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Importance of quinolizidine alkaloids in the relationship between larvae of Uresiphita reversalis (Lepidoptera: Pyralidae) and a host plant, Genista monspessulana

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Abstract

Larvae ofUresiphita reversalis feed almost exclusively on legumes in the tribe Genisteae, which characteristically contain a variety of quinolizidine alkaloids. The larvae are aposematic, and onGenista monspessulana, a major host in California, they feed on the youngest leaves, at the periphery of the plant. These leaves, which were preferred over older foliage in choice tests, contained four to five times the level of alkaloid found in older leaves. The major alkaloids detected in these plants were dehydroaphylline andN-methylcytisine, together accounting for 74% of the total. Preliminary analyses showed the alkaloid profile of exuviae from larvae feeding on these plants was very similar to that of the plants. Two alkaloids, sparteine and cytisine, which are known components of some hosts ofU. reversalis, were phagostimulants for fifth-instar larvae when added to sucrose-impregnated glass-fiber disks. In addition, when sparteine was added to foliage ofG. monspessulana, effectively doubling the percent dry weight of alkaloid, the growth rate of late-instar larvae was positively affected. Cytisine added to plants had no discernible effect on growth of larvae. Alkaloid levels in larvae and in their frass were proportional to levels in the plants on which they fed. Although the majority of alkaloid was excreted, that which was sequestered by the insect was found entirely in the integument, possibly confering some protection from predators.

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... At ABS, L. diffusus occurs at low densities primarily in sandy, elevated sites dominated by slash pine, Pinus elliottii. The herbivore, larvae of the genista moth, Uresiphita reversalis (Lepidoptera: Crambidae) (Fig. 1), is oligophagous, feeding on species in quinolizidine-alkaloid-containing tribes of the Fabaceae (Leen 1997), though appearing restricted to L. diffusus at ABS. Larvae sequester host alkaloids as an anti-predator defence (Montllor et al. 1990) and are aposematically coloured with black, white and chartreuse markings. On L. diffusus, younger larvae are found primarily on upper, younger foliage and shoot tips, where they establish weak silk shelters and characteristically chew out leaves, leaving a papery, translucent window; older larvae are found on lower foliage and consume leaf material completely (M. ...
... This segregation would avoid direct competition, and could also improve food quality for younger larvae by altering source-sink relationships within the plant, by lowering overall plant resistance, and/or by causing induction of defences in lower leaves at the expense of upper leaf tissue. Higher plant quality may have led to greater survival in mixed-age groups if quinolizidine resistance traits were sufficiently toxic (Montllor et al. 1990). These mechanisms have been suggested for other gregarious larval herbivores in the Lepidoptera, but only in the context of the numerical benefits of group feeding (Clark and Faeth 1997;Denno and Benrey 1997;Fordyce 2003;Reader and Hochuli 2003). ...
... A second mechanism for benefits of mixed-age groups could involve a reduction in predation risk. Subject to significant predation risk in other habitats (Bernays 1997), Uresiphita reversalis is warningly coloured, particularly in later instars, and is known to sequester alkaloids for defence against predators (Bernays and Montllor 1989;Montllor et al. 1990). Anti-predation benefits of gregariousness in aposematic species are well known (Hunter 2000), with one proposed mechanism of these benefits being increased signal repellence in larger groups (Gamberale and Tullberg 1998). ...
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Gregarious feeding is a common feature of herbivorous insects and can range from beneficial (e.g. dilution of predation risk) to costly (e.g. competition). Group age structure should influence these costs and benefits, particularly when old and young larvae differ in their feeding mode or apparency to predators. We investigated the relative value of gregarious feeding by aposematic larvae of Uresiphita reversalis that we observed feeding in groups of mixed ages and variable densities on wild Lupinus diffusus. In a manipulative field experiment, the survivorship and growth of young larvae were enhanced in the presence of older conspecifics, but not in large groups of similarly aged larvae. Estimates of insect damage and induced plant responses suggest that mixed-age groups enhance plant quality for young larvae while avoiding competition. We conclude that benefits of gregariousness in this species are contingent on group age structure, a finding of significance for the ecology and evolution of gregariousness and other social behaviours.
... It is assumed that aposematism evolved in response to vertebrate predators such as birds because they are visual hunters capable of learning to avoid distasteful prey. In addition, aposematic Lepidoptera often store plant compounds that are known vertebrate toxins, such as cardenolides (e.g., Brower, 1984), alkaloids (e.g., Rothschild et al., 1979;Kelly et al., 1987;Boppr6, 1990;Montllor et al., 1990), cyanogens (e.g., Jones et al., 1962;Nahrstedt and Davis, 1983;Franzl et al., 1988), or the more unusual azoxyglycosides (Bowers and Latin, 1989). As a result of the association between aposematism and vertebrate predation, the importance of invertebrate (arthropod) predation on aposematic species is seldom studied. ...
... Larvae of Uresiphita reversalis have typically aposematic features. They are brown with white, black, and yellow patches laterally on each segment, feed conspicuously on terminal branches of their hosts (Bernays and Montllor, 1989), and sequester quinolizidine alkaloids (QAs) from Genista monspessulana (Papilionaceae), a major host plant in California (Montllor et al., 1990). Although the larvae excrete most of the QAs ingested, about 1% is retained and deposited in the larval cuticle, which contains about 2.5% dry weight QAs in the last larval instar (Montllor et al., 1990). ...
... They are brown with white, black, and yellow patches laterally on each segment, feed conspicuously on terminal branches of their hosts (Bernays and Montllor, 1989), and sequester quinolizidine alkaloids (QAs) from Genista monspessulana (Papilionaceae), a major host plant in California (Montllor et al., 1990). Although the larvae excrete most of the QAs ingested, about 1% is retained and deposited in the larval cuticle, which contains about 2.5% dry weight QAs in the last larval instar (Montllor et al., 1990). Two hymenopteran predators, the Argentine ant, Iridomyrmex humilis, and the paper wasp Mischocyttarus flavitarsus, have been shown previously to strongly prefer other, more palatable, lepidopteran larvae over U. reversalis in choice tests (Bernays, 1988;Bernays and Cornelius, 1989). ...
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Larvae ofUresiphita reversalis (Guenée) (Lepidoptera: Pyralidae) sequester quinolizidine alkaloids from their leguminous hosts and store them primarily in the cuticle. Stored alkaloids are lost with the last larval molt. Extracts of late-instar larvae and of pupae were applied to larvae of the potato tuber moth,Phthorimaea operculella (Zeller) (Gelichiidae), which are normally palatable to two hymenopteran predators, the Argentine ant,Iridomyrmex humilis (Mayr) (Formicidae), and the paper wasp,Mischocyttarus flavitarsus (Sauss.) (Vespidae). Larvae ofP. operculella treated with alkaloid extracts ofU. reversalis larval exuviae, or with surface extracts of whole larvae, were deterrent to both predators, compared to untreated prey. Extracts of pupal exuviae added toP. operculella, however, were not deterrent.P. operculella larvae treated with the authentic alkaloids sparteine and cytisine were also deterrent to these hymenopteran predators. Storage of small but concentrated amounts of plant secondary compounds in the cuticle appears to be an efficacious means of defense against at least two common predators of lepidopteran larvae.
... However, the plants used in this experiment were initially small seedlings, and the impact of A. hakani on larger plants remains unclear. Levels of resistance and tolerance may change as French broom plants grow; as a fast-growing weed, French broom is more likely to allocate resources to tolerance, although its leaves and stems contain defensive alkaloids (Montllor et al. 1990). For woody plants, herbivory by phloem feeders appears to affect seedlings more strongly than mature plants (Zvereva et al. 2010), and experiments examining the effects of A. hakani on seedlings in comparison to larger plants could yield differing results. ...
... Tolerance may remain constant across ontogeny in many plant species (Barton 2013). Although chemical defenses often change markedly as plants grow (Barton and Koricheva 2010), little is known about changes in chemical defenses of French broom (Montllor et al. 1990). Plant size did not influence nymphal performance of A. hakani in the current study (as measured by survival to adulthood and development time). ...
Article
The impacts of weed biological control agents may vary with plant ontogeny. As plants grow, structural and chemical changes can alter plant resistance, which may reduce herbivory via chemical or structural defenses, and plant tolerance, which may enable plants to maintain fitness despite attack. Resistance and tolerance generally increase as plants grow. Nonetheless, prerelease tests of agent efficacy often overlook plant ontogeny. Here, we assess the performance and impacts of a candidate biocontrol agent, the psyllid Arytinnis hakani (Loginova), in relation to the age of its host plant, the invasive shrub French broom, Genista monspessulana. We also examined whether the psyllid can consistently kill plants when its densities are sufficiently high. Survival of psyllids to adulthood and the timing of adult emergence did not differ between plant sizes, indicating that performance of nymphs was not influenced by plant size. However, adult psyllid survival was reduced on small plants, suggesting that nymphs and adults responded differently to ontogenetic changes in plant quality. Psyllids affected the growth of small and large plants similarly; all measured plant growth parameters were lower in the presence of psyllids regardless of plant size. In a separate experiment, effects on plant survival depended on psyllid density, as higher realized densities of ∼9 psyllids per cm stem length were necessary to consistently kill plants. Thus, results suggest that the psyllid would be equally effective on a range of plant sizes, particularly at high densities, and show the potential of the psyllid to help control French broom in California.
... Larval integument: 2.5% DW; adult: possibly silk glands, transfer to eggs Montllor et al. (1990), , Nihei et al. (2002) Lotus corniculatus, L. japonicus ...
... However, the total QA concentrations in larvae were found, on average, to be only one-fifth of the level of alkaloids found in the larval host plant, Genista monspessulana (Fabaceae), whereas the larval frass contained 1.4 times the levels in this plant. No QAs were detected in pupae, indicating that they were concentrated exclusively in the cuticle (Montllor et al. 1990), but were lost with the exuvia at eclosion . The QA sequestration by these larvae is highly selective; only QAs of the a-pyridone type are taken up, whereas QAs of the aphylline type are excreted. ...
Article
Most plant families are distinguished by characteristic secondary metabolites, which can function as putative defence against herbivores. However, many herbivorous insects of different orders can make use of these plant-synthesised compounds by ingesting and storing them in their body tissue or integument. Such sequestration of putatively unpalatable or toxic metabolites can enhance the insects’ own defence against enemies and may also be involved in reproductive behaviour. This review gives a comprehensive overview of all groups of secondary plant metabolites for which sequestration by insect herbivores belonging to different orders has been demonstrated. Sequestered compounds include various aromatic compounds, nitrogen-containing metabolites such as alkaloids, cyanogenic glycosides, glucosinolates and other sulphur-containing metabolites, and isoprenoids such as cardiac glycosides, cucurbitacins, iridoid glycosides and others. Sequestration of plant compounds has been investigated most in insects feeding or gathering on Apocynaceae s.l. (Apocynoideae, Asclepiaoideae), Aristolochiaceae, Asteraceae, Boraginaceae, Fabaceae and Plantaginaceae, but it also occurs for some gymnosperms and even lichens. In total, more than 250 insect species have been shown to sequester plant metabolites from at least 40 plant families. Sequestration predominates in the Coleoptera and Lepidoptera, but also occurs frequently in the orders Heteroptera, Hymenoptera, Orthoptera and Sternorrhyncha. Patterns of sequestration mechanisms for various compound classes and common or individual features occurring in different insect orders are highlighted. More research is needed to elucidate the specific transport mechanisms and the physiological processes of sequestration in various insect species.
... Caterpillars of the pyralid moth Uresiphita reversalis (Guenée) feed extensively on sky-blue lupines in ridge sandhills of Florida, sometimes resulting in defoliation of individual plants. This moth is a multivoltine species recorded widely in North America, especially in coastal regions, that specializes in feeding on legumes in the tribe Genisteae (Kimball, 1965;Munroe, 1976;Bernays and Montllor, 1989;Montllor et al., 1990). The larvae (second to fifth instars) are highly aposematic: they are brightly colored, they feed in groups during daytime on exposed leaf surfaces, and they are relatively inactive even on hot days (Bernays and Montllor, 1989; J. Carrel, unpubl. ...
... obs.). As a chemical defense, the larvae selectively sequester bitter tasting and toxic QA from the leguminous hosts and concentrate them predominantly in their integument (Montllor et al., 1990(Montllor et al., , 1991Wink et al., 1991;Wink, 1992). But field studies conducted in California reveal that, despite the presence of defensive chemicals, mortality of the first four instars is high (~70% of larvae die in the 3-4 wk required to develop from hatching to fifth instar). ...
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Extensive observations of aposematic Uresiphita reversalis (Guenée) larvae feeding on sky-blue lupine Lupinus cumulicola Small in February in south Florida revealed a low incidence of predation by natural arthropod enemies. Three species of spiders, the wolf spiders Lycosa ceratiola Gertsch and Wallace and L. osceola Gertsch & Wallace and the crab spider Misumenops sp., rejected U. reversalis larvae that were offered to them in laboratory predation tests. However, the green lynx spider Peucetia viridans (Hentz) and the assassin bug Zelus longipes (L.) were found to feed on the caterpillars. Bioassays with the wolf spider L. ceratiola confirmed previous studies showing that the larval integument possess potent antifeedant properties, most likely because it contains quinolizidine alkaloids of dietary origin.
... Consequently, specialists are found more often on herbaceous plants with qualitative defenses (both N-based and more toxic classes of C-based compounds), which are defined as having toxic effects on herbivores. Many specialist herbivores adapt to these qualitative defenses and are often capable of sequestering them to use in defense against their own predators and parasites (Rhoades and Cates 1976; Montllor et al. 1990; Dobler and Rowell-Rahier 1994; Theodoratus and Bowers 1999; Zalucki and Malcolm 1999; Dyer 1995; Engler-Chaouat and Gilber 2007; but see Agrawal and Kurashige 2003). Generalist herbivores, in contrast, are not as likely to be adapted to toxic defenses, and feed broadly on more apparent plants with dose-dependent, C-based defenses (Rhoades and Cates 1976; Rhoades 1979). ...
... Thus, the literature synthesized here supports the plant apparency hypothesis in terms of patterns of plant defense production among plant types but not in terms of the roles of herbivores in driving the evolution of these defenses. The apparent resistance of specialists to plant chemistry may reflect their ability to metabolize or sequester plant secondary metabolites (e.g., Montllor et al. 1990; Dobler and Rowell-Rahier 1994; Zalucki and Malcolm 1999; Dyer 1995; Engler-Chaouat and Gilber 2007). As predicted, statistical differences between the effects of broad classes of plant defenses were greater for specialists than generalists (using herbivory, growth, and consumption as response variables). ...
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Variation in plant secondary metabolite content can arise due to environmental and genetic variables. Because these metabolites are important in modifying a plant’s interaction with the environment, many studies have examined patterns of variation in plant secondary metabolites. Investigations of chemical defenses are often linked to questions about the efficacies of plant defenses and hypotheses on their evolution in different plant guilds. We performed a series of meta-analyses to examine the importance of environmental and genetic sources of variation in secondary metabolites as well as the antiherbivore properties of different classes of defense. We found both environmental and genetic variation affect secondary metabolite production, supporting continued study of the carbon-nutrient balance and growth-differentiation balance hypotheses. Defenses in woody plants are more affected by genetic variation, and herbaceous plant defenses are more influenced by environmental variation. Plant defenses in agricultural and natural systems show similar responses to manipulations, as do plants in laboratory, greenhouse, or field studies. What does such variation mean to herbivores? A comparison of biotic, physical, and chemical defenses revealed the most effective defensive strategy for a plant is biotic mutualisms with ants. Fast-growing plants are most often defended with qualitative defenses and slow-growing plants with quantitative defenses, as the plant apparency and resource availability hypotheses predict. However, we found the resource availability hypothesis provides the best explanation for the evolution of plant defenses, but the fact that there is considerable genetic and environmental variation in defenses indicates herbivores can affect plant chemistry in ecological and evolutionary time. KeywordsHerbivory–Generalist–Genetic variation–Phenotype–Plant defense–Secondary metabolites–Specialist
... In addition, N-methylcytisine, cytisine, tetrahydrorhombifoline , 17-oxosparteine, 5,6-dehydrolupanine, lupanine, 17-oxolupanine, baptifoline, and 13-tigloyloxylupanine were detected as the minor alkaloids in the plant. There are a number of reports on the alkaloid patterns of Genista species by capillary GC-MS (Montllor et al., 1990; Greinwald et al., 1992; Kirch et al., 1995; Pistelli et al., 2001; Martins et al., 2005). In the Montllor et al. (1990) study, dehydroaphyllidine and N-methylcytisine were detected as the major alkaloids in G. monspessulana, together accounting for 74% of the total alkaloids. ...
... There are a number of reports on the alkaloid patterns of Genista species by capillary GC-MS (Montllor et al., 1990; Greinwald et al., 1992; Kirch et al., 1995; Pistelli et al., 2001; Martins et al., 2005). In the Montllor et al. (1990) study, dehydroaphyllidine and N-methylcytisine were detected as the major alkaloids in G. monspessulana, together accounting for 74% of the total alkaloids. Greinwald et al. (1992) investigated the alkaloid pattern of G. cinerea subsp. ...
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In the present study, the alkaloid composition of the aerial parts of Genista vuralii A. Duran & H. Dural (Fabaceae) was investigated by capillary GC-MS. Ten quinolizidine alkaloids were identified by capillary GC-MS, namely, N-methylcytisine, cytisine, tetrahydrorhombifoline, 17-oxosparteine, 5,6-dehydrolupanine, lupanine, 17-oxolupanine, anagyrine, baptifoline, and 13α-tigloyloxylupanine. Among them, anagyrine (93.04%) was the most abundant alkaloid. Furthermore, antibacterial and antifungal activities of the alkaloid extract of G. vuralii were tested against standard strains of bacteria (Escherichia coli, Pseudomonas aeruginosa, Bacillus subtilis, Staphylococcus aureus) as well as fungi (Candida albicans, Candida krusei). The alkaloid extract of G. vuralii presented good activity against S. aureus, B. subtilis, and C. krusei, with minimum inhibitory concentrations (MIC) of 62.5 μg/mL. The remaining MIC values were found to range between 125 and 500 μg/mL. To the best of our knowledge, the current work is the first to report the alkaloid profile and antimicrobial activity of G. vuralii L. growing in Turkey.
... To determine if ergot alkaloids are sequestered by the insects that feed on endophytic perennial ryegrass I followed the method described by Montllor et al. (1990) in which they starved the insects for 24 h to empty their gut prior to analysis. The insects were frozen for 24 h at -20°C before being freeze-dried for 1 wk at -20°C. ...
... Although there were detectable levels of alkaloids in frass it appears as if some of these alkaloids are maintained or persist in the insect (Fig. 5.2 -5.3). Montllor et al. (1990) found that the moth, Uresiphita reversalis, excretes most of the alkaloids consumed, but retains some in the cuticle, which acts as a deterrent to ants and wasps. Boros et al. (1991) found that the noctuid, Lepipolys sp., sequesters iridoid glycosides and stores them through the larva stage until the pupa stage. ...
... For the floristic distribution of chemicals, chemical dictionaries, books, and articles on phytochemistry and systematics were the most helpful (e.g., Kjaer 1960;Williamson and Shubert 1961;Bohlmann et al. 1973;Gibbs 1974;Jensen et al. 1975;Ellis 1977;Stumpf and Conn 1981;Murray et al. 1982;Seaman 1982;Harbourne and Baxter 1993). Web pages, books, agricultural experiment station bulletins, and life-history articles as well as some of the bioassay articles themselves provided most of the information in herbivore host ranges (e.g., Oliver 1907;Mulkern et al. 1964;Soo Hoo andFraenkel 1966a, 1966b;Popov and Ratcliffe 1968;Beckwith 1970;Tietz 1972;Wint 1983;Bowers 1984;Joern 1985;Navon 1985;Montllor et al. 1990). ...
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Literature data were collected on the floristic distribution and toxicity of phytochemicals to herbivores and on herbivore specialization in order to test phytochemical coevolution theory. The theory makes four predictions that can be tested with this information. Herbivores can adapt to novel, more toxic chemicals by becoming specialists, or they can become generalists but at the cost of lower feeding success on any particular host. Thus, the first two predictions are as follows: herbivores should do better on chemicals that are present in their normal host, and this pattern should be stronger for specialists than for generalists. The "escape and radiation" aspect of the theory holds that if a plant taxon with a novel defense chemical diversifies, the chemical will become widespread. Eventually, herbivores will adapt to and disarm it. So the third prediction is that more widespread chemicals are less toxic than more narrowly distributed ones. Because generalists should not do as well as specialists on chemicals disarmed by the latter, the fourth prediction is that the third prediction should be more true for generalists than specialists and should depend on presence/absence of the chemical in the normal host. Multiple regressions of toxicity (herbivore mortality and final weight) on three predictor variables (chemical presence/absence in the normal host, specialism, and chemical floristic distribution) and relevant interactions were used to test these predictions. Chemical presence/absence in the normal host, the interaction between this variable and specialism, and chemical floristic distribution had significant effects on both measures of toxicity, supporting the first three predictions of the model. Support for the fourth prediction (a three-way interaction among all predictor variables) was evident for final weight but not mortality, perhaps because growth is more responsive to toxicity differences than survival. In short, the phytochemistry literature provides broad support for the phytochemical coevolution model.
... There are a handful of cases where phagostimulation by sequestered allelochemicals has been demonstrated (Rowell-Rahier & Pasteels, 1992). For example, curcubitacins act as feeding stimulants to Diabrotica beetles, which sequester these bitter-tasting chemicals and probably use them in anti-predator defence (Metcalf, 1986), and the lepidopteran Uresiphita reversalis sequesters and is stimulated to feed by quinolizidine alkaloids (Montllor et al., 1990). As far as we are aware this is the first report of this phenomenon in sawflies. ...
Article
The sawfly Rhadinoceraea nodicornis Konow (Hymenoptera: Tenthredinidae) is a member of a closely related group of species, the tribe Phymatocerini, which feed on the Liliales and Ranunculales. It is known to sequester steroid alkaloids from its host plants, species in the genus Veratrum (Liliales: Melanthiaceae), and to use them as a defence against predators. There are known chemical relationships between the hosts of R. nodicornis and hosts of related sawfly species. We tested whether the R. nodicornis larvae would accept hosts of closely- and more distantly-related sawflies, but found that they accepted only plant species in the genus Veratrum. This specificity was apparently innate, as it was independent of early larval experience. A feeding bioassay showed that the steroid alkaloids from Veratrum nigrum were phagostimulatory for R. nodicornis larvae, suggesting that they may be involved in host recognition. We discuss the possibility that the evolution of recognition of specific compounds may represent the mechanism of host radiation within the Phymatocerini.
... It was fascinating to discover that small weevils could have most of their body protein tied up in the cuticle! With a postdoc and a German chemist, we showed that quinolizidine alkaloids were important in a caterpillar species, Uresiphita reversalis, on the weed French broom (62). We had worked on it as a potential weed control agent, but the ecology demonstrated that its sensitivity to high levels and intensity of rainfall limited its ability to control spread of the plant. ...
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Elizabeth A. Bernays grew up in Australia and studied at the University of Queensland before traveling in Europe and teaching high school in London. She later obtained a PhD in entomology at London University. Then, as a British government scientist, she worked in England and in developing countries on a variety of projects concerned with feeding by herbivorous insects and their physiology and behavior. In 1983, she was appointed professor at the University of California, Berkeley, where her research expanded to a variety of topics, all related to the physiology, behavior, and ecology of feeding in insects. She was awarded a DSc from the University of London, and at about the same time became head of the Department of Entomology and regentsrsquo professor at the University of Arizona. In Arizona, most of her research involved multiple approaches to the understanding of diet breadth in a variety of phytophagous insect species.
... En algunos casos, el ramoneo resulta en un aumento en la defensa de la biomasa vegetal mientras en otros se reduce la defensa como consecuencia del consumo (BRYANT et al., 1991(BRYANT et al., y 1992. Por otra parte, cuando existe un alto riesgo de consumo, los mecanismos de defensa se incrementan (PROVENZA y MALECHEK, 1986;MONTLOR et al., 1990;NOLAN y NASTIS, 1997). ...
... Cultured larvae reared on this food plant contained IGs to the same order of magnitude as the plant tissue, and so did the larval frass (Mead et al., 1993), clearly demonstrating less than 100 % sequestration. Among Papilionidae sequestering non-glucosidic compounds such as aristolochic acids, quinolizidine alkaloids, or pyrrolizidine alkaloids, the recovery of compounds in larvae can be estimated to correspond to either 0.5-50 % of ingested compounds, or up to 1 g of plant material (Montllor et al., 1990;Vonnickischrosenegk and Wink, 1993;Pinto et al., 2011). ...
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Sequestration of plant secondary metabolites is a widespread phenomenon among aposematic insects. Sarmentosin is an unsaturated γ-hydroxynitrile glucoside known from plants and some Lepidoptera. It is structurally and biosynthetically closely related to cyanogenic glucosides, which are commonly sequestered from food plants and/or de novo synthesized by lepidopteran species. Sarmentosin was found previously in Parnassius (Papilionidae) butterflies, but it was not known how the occurrence was related to food plants or whether Parnassius species could biosynthesize the compound. Here, we report on the occurrence of sarmentosin and related compounds in four different Parnassius species belonging to two different clades, as well as their known and suspected food plants. There were dramatic differences between the two clades, with P. apollo and P. smintheus from the Apollo group containing high amounts of sarmentosin, and P. clodius and P. mnemosyne from the Mnemosyne group containing low or no detectable amounts. This was reflected in the larval food plants; P. apollo and P. smintheus larvae feed on Sedum species (Crassulaceae), which all contained considerable amounts of sarmentosin, while the known food plants of the two other species, Dicentra and Corydalis (Fumariaceae), had no detectable levels of sarmentosin. All insects and plants containing sarmentosin also contained other biosynthetically related hydroxynitrile glucosides in patterns previously reported for plants, but not for insects. Not all findings could be explained by sequestration alone and we therefore hypothesize that Parnassius species are able to de novo synthesize sarmentosin.
... Relative contents of % alkaloids were determined via areas under the peaks from total ion chromatography using Hewlett Packard software. A number of studies on the alkaloid patterns of Genista species have been determined by capillary GC-MS [15,[18][19][20]. Our results compared with literature findings, the alkaloid compositions were similar, but the relative amount of the alkaloids showed a higher diversity. ...
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Alkaloid profile of the aerial parts of Genista sandrasica Hartvig & Strid. (Fabaceae) growing in Turkey was studied by capillary gas chromatography-mass spectrometry (GC-MS). Ten quinolizidine alkaloids were identified in the alkaloid extract of G. sandrasica. The main alkaloids were: sparteine (13.68%), N-acetylcytisine (6.48%), 13-methoxylupanine (13.12%), anagyrine (40.49%) and baptifoline (10.76%). In addition, antibacterial and antifungal activities of the alkaloid extract of G. sandrasica were tested against standard strains of the bacteria (Escherichia coli, Pseudomonas aeruginosa, Bacillus subtilis and Staphylococcus aureus) as well as the fungi (Candida albicans and Candida krusei). The alkaloid extract of G. sandrasica showed significant activity against B. subtilis and S. aureus with minimum inhibitory concentrations (MIC) of 31.25 and 62.5 µg/mL.
... In aposematic species unpalatability is coupled with a warning coloration which can have many conse-quences for the biology and ecology of these species. Many "chemically defended" Lepidoptera are aposematic, and store plant compounds that are known vertebrate toxins, such as cardenolides (Brower, 1984), alkaloids (Rothschild et al., 1979;Boppre, 1990;Montllor et al., 1990), and cyanogens (Jones et al., 1962). Chemical defense of aposematic insects has also been shown to be effective against invertebrate predators, which can learn to subsequently avoid similar prey (Montllor and Bernays, 1993). ...
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El secuestro de compuestos de defensa de las plantas hospederas puede requerir adaptaciones fisiológicas particulares para que las larvas los ingieran, acumulen y almacenen. Los compuestos de defensa son usados para varios propósitos, particularmente contra depredadores, donde la defensa química reduce el riesgo de depredación. La cicasina es un metabolito secundario presente en las cícadas (Cycadales), que son hospederas de mariposas del género Eumaeus (Lycaenidae). La cicasina es secuestrada por la mariposa aposemática E. minyas de su planta hospedera Zamia loddigesii (Zamiaceae) y es usada como defensa química. En experimentos de campo y laboratorio se evaluó la presencia de cicasina en todos los estadios de E. minyas. Mediante experimentos de palatabilidad en el laboratorio, se estableció que la cicasina pura repele a Solenopsis geminata (Hymenoptera: Formicidae), un depredador potencial de E. minyas y, al utilizar extractos de huevos, larvas y adultos de esta mariposa se obtiene el mismo efecto de manera experimental. Para evaluar la eficiencia de esta defensa química en huevos y larvas en condiciones naturales, se realizó un experimento de exclusión de depredadores. Usando un análisis de sobrevivencia se demostró que el número de huevos y larvas sobrevivientes fue significativamente más alto en las exclusiones, sugiriendo que la función protectiva de la cicasina en condiciones naturales no es totalmente efectiva contra los depredadores naturales. Este es el primer estudio que incluye manipulación experimental de la función protectiva de la cicasina en condiciones naturales. Sugerimos que la cicasina en la mariposa aposemática E. minyas tiene una función defensiva contra los depredadores; sin embargo, sus poblaciones pueden estar reguladas por el efecto negativo de sus depredadores, los cuales aparentemente saltan la barrera química defensiva y por el canibalismo.
... Some of these waste-based structures may well be repellent or deterrent to natural enemies, especially if their hosts are chemically 'noxious'. In many species, plant toxins are, in fact, eliminated in regurgitants or digestive wastes (Self et al. 1964; Bowers & Puttick 1986; Blum et al. 1987; Fiedler et al. 1993; Bowers & Larin 1989; Ehmke et al. 1991; Montllor et al. 1990; Rojas et al. 1992; Szentesi & Wink 1991). However, only a few of these fore and aft enteric discharges have been demonstrated to effectively thwart predators (Eisner et al. 1967; Brower 1988; Peterson et al. 1987). ...
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Summary. Both adults and larvae of the sumac flea beetle, Blepharida rhois (Forster), are dietary specialists that feed on smooth sumac, Rhus glabra, on Long Island, NY. Instead of discarding their feces, B. rhois larvae retain it on their backs to form fecal 'shields'. We observed that ants attacking shielded larvae retreated and groomed vigorously, indicating the possible presence of chemical deterrents. To examine whether shields were chemical rather physical barriers against predation, we employed a generalist ant predator as a bioassay. Shields of larvae reared on R. glabra thwarted ants while larvae that had their shields removed were readily taken. Moreover, larvae reared on a substitute diet of lettuce were defenseless. However, protection was restored after their lettuce-derived shields were replaced with shields obtained from larvae reared on R. glabra. We then extracted and fractionated shields in order to locate active deterrents. To determine whether larvae synthesized defensive compounds or obtained them from the host, leaves were also analyzed and compared to the chemicals found in shields. The shield defense was a mixture of three fatty acids, a suite of tannins, their metabolites and phytol. All shield compounds or their precursors were obtained entirely from the host plant. Pure standards of shield compounds were found to be deterrent when assayed. This is one of the first instances of an insect using a mixture of primary and secondary substances for defense against predators.
... Typically al- kaloids are deterrents to feeding by generalist insects, but attractants for more specialized insects. For example, quinolizidine alkaloids in Genista mospessulana are thought to maintain exclusive host use by Uresiphita reversalis (Lepidoptera: Pyralidae) ( Montlor et al., 1990). Also, pyrrolizidine alkaloids of Heliotropium in- dicum are powerful attractants for male Ithomiine and Danaine butterflies to their host plant ( Pliske et al., 1976). ...
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Prediction of host plant range and ecological impact of exotic phytophagous insects, such as insects for classical biological control of weeds, represents a major challenge. Recently, the flowerhead weevil (Rhinocyllus conicus Fröl.), introduced from Europe into North America to control exotic thistles (Carduus spp.), has become invasive. It feeds heavily on some, but not all species of native North American thistles (Cirsium spp.). We hypothesized that such non-target use among native plants could be better predicted by knowledge of characteristic chemical profiles of secondary compounds to supplement the results of host specificity testing. To evaluate this hypothesis, we reviewed the literature on the chemistry of Cirsium and Carduus thistles. We asked what compounds are known to be present, what is known about their biological activity, and whether such information on chemical profiles would have better predicted realized host range and ecological effects of R. conicus in North America. We found an extensive, but incomplete literature on the chemistry of true thistles. Two main patterns emerged. First, consistent chemical similarities and interesting differences occur among species of thistles. Second, variation occurs in biologically active groups of characteristic compounds, specifically flavonoids, sterols, alkaloids and phenolic acids, that are known to influence host plant acceptance, selection, and feeding by phytophagous insects. Surprisingly, sesquiterpene lactones, which are characterisitic in closely related Asteraceae, have not been extensively reported for Cirsium or Carduus. The minimal evidence on sesquiterpene lactones may reflect extraction methods vs. true absence. In summary, our review suggests further research on thistle chemistry in insect feeding is warranted. Also, since the exotic Canada thistle (Cirsium arvense) is an invasive thistle of current concern in North America, such research on mechanisms underlying host range expansion by exotic insects would be useful.
... Nihei et al. 2002). Species such as Uresiphita reversalis, for example, are known to sequester quinolizidine alkaloid from its host plants and use it as a defence as they become aposematic or toxic to predators (Bernays & Montllor 1989;Montllor et al. 1990). ...
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In a three-hour bioassay, we tested the palatability and feeding preferences of Uresiphita maorialis (kōwhai moth) for Sophora tetraptera, Sophora microphylla and Sophora prostrata. Palatability tests showed no differences among the Sophora species. Feeding preferences, on the other hand, showed that S. tetraptera and S. microphylla leaves are preferred over S. prostrata leaves. Our results support our field observations in Wellington city parks and gardens showing that S. tetraptera and S. microphylla plants frequently have higher densities of larvae than S. prostrata
... Among Lepidoptera that sequester plant allelochemicals, deposition of the defensive compounds in the larval integument is indeed common and occurs in diverse taxa. The compounds include quinolizidine alkaloids in Uresephita reversalis (Guene e) (Pyralidae) (Montllor et al., 1990; Wink et al., 1991), pyrrolizidine alkaloids in various Arctiidae (Wink & Schneider, 1990; von Nickisch-Rosenegk & Wink, 1993), cannabinoids in Arctia caja (L.) (Arctiidae) (Rothschild et al., 1977), cardenolides in Syntomeida epilais (Walker) (Arctiidae) (von Nickisch-Rosenegk et al., 1990), cyanoglucosides in Zygaena (Franzl et al., 1988), and iridoid glycosides in Nymphalidae (Bowers, 1993). Except for the case of U. reversalis, the surface chemistry of which deters ants and vespid wasps (Montllor et al., 1991), these sequestration studies are not accompanied by direct tests (i.e. ...
Article
Abstract 1. Parasitoids in the genus Trogus (Hymenoptera: Ichneumonidae) attack the larvae of swallowtail butterflies (Lepidoptera: Papilionidae). Only two of the three major tribes of the subfamily Papilioninae are attacked although species of all three tribes commonly occur together. The tribe Troidini is relatively free of parasitoids of any kind, and it has been proposed that the aristolochic acids sequestered by troidines protect them from parasitism. 2. The responses of T. pennator (Fabricius) to the sympatric troidine Battus philenor (Linnaeus) were examined. Three hypotheses that could explain why this wasp does not parasitise B. philenor were considered. (1) Battus philenor does not produce compounds used by the wasp to locate hosts. (2) The larval integument contains compounds that deter attack. (3) The parasitoid offspring cannot survive in B. philenor. 3. The first hypothesis was not supported as the frass of B. philenor larvae was found to act as a searching arrestant comparable to the frass of a host species. 4. The second hypothesis was supported. The B. philenor larvae were rejected when the wasps examined them using their antennae, and ethanolic washes of B. philenor cuticle deterred attack by T. pennator when applied to otherwise acceptable host larvae. Bioassays of fractions of the ethanolic wash and of pure aristolochic acids established that aristolochic acids were at least partly responsible for the deterrent effect. 5. The third hypothesis was also supported. Larvae of B. philenor attacked by the parasitoids developed into butterflies. 6. These results indicate that both behavioural and physiological barriers, the former attributable at least in part to sequestered compounds and the latter of unknown mechanism, prevent T. pennator from parasitising B. philenor.
... Native herbivores could select for the maintenance of QA expression in introduced G. monspessulana. For example, some QAs are phagostimulants for U. reversalis larvae (Montllor et al. 1990), which also sequester QAs from the plant to deter predators (Montllor et al. 1991). Surveys identifying and quantifying local native herbivores on introduced G. monspessulana populations in the U.S. are lacking, but should be conducted to increase our understanding of the influence that these herbivores might have on the evolution of chemical defenses in invasive G. monspessulana populations. ...
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The evolution of redirecting resources from plant defense to growth or reproduction may explain why some exotic species are successful invaders in new environments. For example, the evolution of increased competitive ability hypothesis posits that escape from herbivores by invasive plants results in the selection of more vigorous genotypes that reduce their allocation of resources to defense. In addition, understanding the defense strategy of an invasive plant may help forecast the likely impact of herbivory. We tested the prediction of reduced defense (i.e., resistance) in Genista monspessulana, measured indirectly as the performance of a specialist psyllid herbivore, by comparing five native and introduced plant populations. We also examined the ability of G. monspessulana to compensate for herbivory in the presence and the absence of psyllids for a single plant population from the native and introduced regions. Plant origin (native or introduced) did not influence the psyllid’s abundance and population growth rate, suggesting no change in resistance to herbivory for introduced plants. Similarly, we found no overall difference in plant performance between individuals in the presence and the absence of psyllid herbivory, suggesting that G. monspessulana was able to fully compensate for herbivory. Damaged plants compensated by changing the pattern of branching, which also resulted in greater dry leaf biomass. We conclude that evolution of reduced defenses does not explain the success of G. monspessulana as an invader and that compensation for herbivory may limit the efficacy of the psyllid as a biological control agent. © 2015, Springer Science+Business Media Dordrecht (outside the USA).
... Only few insects have adapted to quinolizidine alkaloids and sequester them as defense compounds, e.g., some aphids and larvae of the pyralid moth Uresiphita reversalis (Wink and Witte, 1991 ;Montllor et al., 1990) . This is in contrast to pyrrolizidines, which are utilized by a large number of butterflies and beetles. ...
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Plants produce an enormous variety of natural products with highly diverse structures. These products are commonly termed “secondary metabolites” in contrast to the “primary metabolites” which are essential for plant growth and development. Secondary metabolites were formerly regarded as “waste products” without physiological function for the plant. With the emergence of the field of chemical ecology about 30 years ago, it became evident, however, that these natural products fulfill important functions in the interaction between plants and their biotic and abiotic environment. They can serve, for example, as defense compounds against herbivores and pathogens, as flower pigments that attract pollinators, or as hormones or signal molecules. In addition to their physiological function in plants, natural products also have a strong impact on human culture and have been used throughout human history as condiments, pigments, and pharma­ceuticals. This chapter provides an overview about the diversity of secondary metabolites in plants, their multiple biological functions and multi-faceted cultural history. The compounds are classified into four different groups according to their biosynthetic origin: alkaloids, phenylpropanoids, polyketides, and terpenoids. Since more than 200,000 structures of natural products from plants are known, only selected groups and compounds are presented.
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The genus Psiadia Jacq. represents the most important indigenous genus, by the number of species present, in the Mascarene archipelago (Mauritius, Reunion, Rodrigues), and is a typical example of adaptive radiation in oceanic islands. The Mauritius species are used in traditional pharmacopoeia for their expectorant properties, and most of them are heavily threatened. Molecular genetic relationships between representatives of eight endangered endemic Psiadia species from Mauritius, conserved in Le Mondrain Reserve, and P. dentata (Cass.) DC, endemic from Reunion island, were studied. The absence of length variations of the 5s rDNA non-transcribed spacer demonstrated the recent common origin of all the species surveyed. RAPD analysis revealed a relatively high intra-specific variability in accordance with the outcrossing mode of reproduction of Psiadia species. Moreover, RAPD analysis showed the existence of four major phenetic groups: (A) P. arguta (Pers.) Voigt, P. dentata, (B) P. penninervia D. C., P. terebinthina A.J. Scott, P. lithospermifolia (Lam.) Cordem, (C) P. viscosa (Lam.) A.J. Scott, P. canescens A.J. Scott, P. cataractae A.J. Scott, and (D) P. pollicina A.J. Scott. These groups were consistent with the chemical composition of the essential oils of the species as well as with their floral characteristics, based on literature. A molecular germplasm database for Psiadia species was established, which will allow further characterisation of new samples being introduced in Le Mondrain Reserve for conservation purpose.
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A survey of the literature and museum collections of Uresiphita indicates larval hosts are primarily quinolizidine-bearing plants in tribes of the Fabaceae. Three species, Uresiphita reversalis, U. ornithopteralis and U. polygonalis, were collected from seven genera in the Genisteae (Chamaecytisus, Genista, Lupinus, Spartium, Laburnum, Ulex and Cytisus) and from three genera in the Sophoreae (Sophora, Pericopsis and Bolusanthus). Two species, U. reversalis and U. polygonalis, were collected from three genera in the Thermopsidae (Baptisia, Anagyris and Piptanthus) and two, U. reversalis and U. ornithopteralis, were collected from two genera in the Bossiaceeae (Hovea and Templetonia). A few legume species that are not known to bear quinolizidine alkaloids were also reported. In particular, U. reversalis, U. polygonalis, and U. ornithopteralis were each collected from Acacia (Mimosaceae) in areas as widely distributed as Australia and the United States (California, Texas and Hawaii). This is a consistent anomaly in the over-all host-use pattern. Other nonleguminous species have been reported but are probably not indicative of hosts upon which development may be completed.
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A number of aposematic butterfly and diurnal moth species sequester unpalatable or toxic substances from their host plants rather than manufacturing their own defensive substances. Despite a great diversity in their life histories, there are some general features in the selective utilization of plant secondary metabolites to achieve effective protection from predators. This review illustrates the biochemical, physiological, and ecological characteristics of phytochemical-based defense systems that can shed light on the evolution of the widely developed sequestering lifestyles among the Lepidoptera.
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This study describes the chemical ecology of a tritrophic interaction among species endemic to the island of Hawaii, USA: a tree (Sophora chrysophylla: mamane), an endangered bird (Loxioides bailleui; palila), and moth larvae (Cydia spp.). Palila and Cydia both specialize on the seed embryos of mamane but avoid eating the seed coats. Palila actively seek out and feed mamane embryos and Cydia larvae to their nestlings. Because mamane embryos contain potentially toxic levels of alkaloids, including broadly toxic quinolizidine alkaloids, and because insects often sequester alkaloids from their food plants, we focus on the questions of why palila forage upon mamane embryos and why they supplement their diet with Cydia larvae. Our data show that mamane embryos contain high amounts of potentially toxic alkaloids, but are well balanced nutritionally and contain lipids, carbohydrates, proteins, amino acids, and minerals at levels that are likely to be sufficient for maintenance and breeding. Mamane seed coats contain lower levels of alkaloids and nutrients, somewhat higher levels of phenolics, and much higher levels of nondigestible fiber. Taken together, these results suggest that palila have evolved tolerance to high levels of alkaloids and that they forage upon embryos primarily because of their availability in the habitat and high nutritional reward. Our data also suggest that Cydia are used by palila because they are readily accessible, nontoxic, and nutritious; the larvae apparently do not sequester alkaloids while feeding upon mamane seeds. Our results are interpreted with respect to the likelihood of current and historical coadaptive responses in this ecologically isolated and simplified island setting.
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Quinolizidine alkaloids, found in the leaves of Cytisus monspessulanus L. (Leguminosae), were characterized in the cuticle of larvae of the pyralid moth Uresiphita reversalis (Lepidoptera: Pyralidae) when the latter were fed on this weed. By GC-MS analysis of the methanolic extracts of the cuticle, four quinolizidine alkaloids, N-methylcytisine, cytisine, aphylline and anagyrine, were identified as possible defense substances. In addition, the quinolizidine alkaloid, (+)-2,3-dehydro-10-oxo-alpha-isosparteine was characterized in both the insect and host plant.
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Genista monspessulana (L.) L.A.S. Johnson (Fabaceae) is a Mediterranean plant introduced to South America and other regions for ornamental purposes. However, it is considered an invasive shrub due to its reproductive vigor in many areas. Unlike other Genista plants, G. monspessulana has few studies disclosing its biologically active components, particularly cytotoxic agents against cancer cells. Thus, as part of our research on anti-proliferative bioactives, a set of ethanolic seed extracts from ten accessions of G. monspessulana, collected in the Bogotá plateau, were evaluated against four cell lines: PC-3 (prostate adenocarcinoma), SiHa (cervical carcinoma), A549 (lung carcinoma), and L929 (normal mouse fibroblasts). Extracts were also analyzed through liquid chromatography coupled with mass spectrometry (LC/MS) to record chemical fingerprints and determine the composition and metabolite variability between accessions. Using multiple covariate statistics, chemical and bioactivity datasets were integrated to recognize patterns and identify bioactive compounds among studied extracts. G. monspessulana seed-derived extracts exhibited dose-dependent antiproliferative activity on PC-3 and SiHa cell lines (>500 µg/mL < IC50 < 26.3 µg/mL). Seven compounds (1–7) were inferred as the compounds most likely responsible for the observed anti-proliferative activity and subsequently isolated and identified by spectroscopic techniques. A tricyclic quinolizidine (1) and a pyranoisoflavone (2) were found to be the most active compounds, exhibiting selectivity against PC-3 cell lines (IC50 < 18.6 µM). These compounds were used as precursors to obtain a quinolizidine-pyranoisoflavone adduct via Betti reaction, improving the activity against PC-3 and comparable to curcumin as the positive control. Results indicated that this composition–activity associative approach is advantageous to finding those bioactive principles efficiently within active extracts. This correlative association can be employed in further studies focused on the targeted isolation of anti-proliferative compounds from Genista plants and accessions.
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The roles of plant and insect cuticular lipids in insect and plant interactions are reviewed. Emphasis is given to the influence that the host plant and the surface lipids of the host plant have upon insect herbivores and the predators and parasitoids of these herbivores. Variations in cuticular lipids of herbivorous insects are dependent upon the host plant, and these variations may affect the behavior of predators and parasitoids. The cuticular lipids of species which interact on multiple trophic levels are compared. Similarities were found between the hydrocarbons of herbivorous insects, their host plants, and their predators or parasitoids.
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Uresiphita reversalis Guenée (Lep., Crambidae) is a North American species whose native hosts include legumes (Fabaceae) in the genera, Lupinus L. (Genisteae, Lupininae), Baptisia Vent. (Thermopsidae) and Sophora L. (Sophoreae). Several species from the Genisteae, subtribe Genistinae, have been introduced to the United States and U. reversalis has expanded its host range to include these species. Members of all of these tribes bear quinolizidine alkaloids (QA). Ovipositional and larval preferences of U. reversalis for both introduced and native species were examined. Adults and larvae prefer Genista L. and thus preference is proposed to be indirectly or directly associated with the presence of QA with higher toxicity in this genus than in other host genera. Larvae of U. reversalis are known to sequester QA, which are deterrent and toxic to their natural enemies.
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This chapter deals with aspects of the occurrence, the spectroscopic characteristics, and the chemical properties of lupine alkaloids that have been isolated. It includes newly proposed biosynthetic pathway, biotechnological studies, a summary of biological activities, and a discussion of chemotaxonomic aspects of the leguminous plants which accumulate lupine alkaloids. More than 200 naturally occurring lupine alkaloids are known, most of which have been isolated from leguminous plants, especially the subfamily Papilionaceae. A considerable number of lupine-type alkaloids have been found in Papaveraceae, Berberidaceae, Solanaceae, Compositae, Chenopodiaceae, Nymphaeaceae, Ranunculaceae, Scrophulariaceae, Ericaceae, Monimiaceae, Adociidae, and Rubiaceae. The leguminous plants that accumulate the common lupine alkaloids are divided into three main groups: plants which produce the matrine, the lupinine, and the cytisine/sparteine-type alkaloids. There are the Muackia species and a few other species that produce rare bases. Although there is at present no useful drug derived from the lupine alkaloids, except for (+)-sparteine that serves as an oxytociduterotonic, the newly found pharmacological properties of the lupine alkaloids.
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This chapter discusses that modern work on alkaloid chemical ecology is highly mechanized, using gas chromatography–mass spectroscopy (GC–MS) or high-performance liquid chromatography (HPLC) with computer libraries of spectra to analyze mixtures and identify compounds. This has multiplied reports on simpler, more volatile, and more variable alkaloids in the studies of chemical ecology, since meaningful data are easy to obtain from these classes with the methods available. Although alkaloid activities are extremely varied and frequently multiple in natural systems, most seem related to the interaction of the lone pair of electrons on nitrogen with DNA synthesis, nerve function, and specific receptors. Enough exceptions are known, however, to be able to predict that many new natural and pharmacological activities of alkaloids have yet to be discovered. The chapter also discusses that it is possible that well-chosen laboratory surrogates for natural herbivores, predators, and pathogens provide reliable data on natural activity. Models are adequate predictors of effects in natural systems, but enough cases of poor correlation are known to cast suspicion on the relevance of laboratory populations to predict ecological activities in the field.
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The weevils Sitona gressorius and Sitona griseus are specialist herbivores on lupins in Europe. The adult weevils feed on the leaves, and the larvae on the root nodules of the plants. This causes severe damage to lupin crops. In the present study, the feeding preferences of lupin weevil adults on different lupin genotypes were examined with respect to a possible effect of lupin alkaloids on host selection. A total of 12 genotypes from the species Lupinus albus, L. angustifolius, L. luteus, and L. nanus were grown in a field experiment and the feeding damage on the leaves caused by naturally occurring lupin weevil adults was estimated. Additionally, a feeding choice test with S. gressorius adults was performed to examine feeding preferences under laboratory conditions. A gas chromatographic analysis provided information on the alkaloid content and profiles in the leaves of the tested lupin genotypes. In the field experiment, significant differences in the extent of the feeding damage within the 12 lupin genotypes were observed. The dual-choice feeding bioassay did not show discrimination of lupin species, but two L. angustifolius genotypes were significantly less affected than the standard L. luteus “Bornal”. The alkaloid analysis revealed large contrasts in alkaloid concentrations and profiles in the leaves of the tested genotypes. Correlation analysis with the results from the field and laboratory did not indicate a significant influence of the total foliar alkaloid content on the extent of weevil feeding.
Chapter
In previous chapters the authors considered the distribution of alkaloids within the plant kingdom and how the plants synthesize, transport, and store them. In this chapter I shall concentrate on the question of the role and function of alkaloids, to what purpose they are produced.
Chapter
Several secondary constituents which are produced by higher plants are used both by plants and also by insects for defense. For example, pyrrolizidine alkaloids accumulate in many Asteraeae and are taken up from the plant tissues by Nymphaelidae or Arctiidae and stored in their body tissues, thus becoming toxic to insectivores.1 The same is true for: cardiac glycosides, produced by Asclepidaceae and used by the monarch butterfly;2,3 mustard oils, produced by Brassicaceae and used by Pieridae;4 quinolizidines, produced by Fabaceae and used by Pyralidae;5,6 the azoxymethanol glucoside cycasin, produced by Cy-cadaceae and used by Lycaenidae.7 Additionally, iridoids,3,8 alkaloidal glycosi-dase inhibitors,9 tropane alkaloids,10 butenolides,11 aristolochic acids,12 and cyanogenic glycosides13,14 also are all exploited to some degree by insects.
Article
Extensive observations of aposematic Uresiphita reversalis (Guenee) larvae feeding on sky-blue lupine Lupinus cumulicola Small in February in south Florida revealed a low incidence of predation by natural arthropod enemies. Three species of spiders, the wolf spiders Lycosa ceratiola Gertsch & Wallace and L osceola Gertsch & Wallace and the crab spider Misumenops sp., rejected U. reversalis larvae that were offered to them in laboratory predation tests. However, the green lynx spider Peucetia viridans (Hentz) and the assassin bug Zelus longipes (L.) were found to feed on the caterpillars. Bioassays with the wolf spider L. ceratiola confirmed previous studies showing that the larval integument possess potent antifeedant properties, most likely because it contains quinolizidine alkaloids of dietary origin.
Article
Although alkaloids are known feeding deterrents for lepidopteran larvae, including the spruce budworm, Choristoneura fumiferana (Clemens), few studies have investigated their effects on lepidopteran oviposition. Quinolizidine-containing alkaloid extracts and isolated quinolizidine alkaloids were obtained from 2 Chinese plants, Sophora alopecuroides L. and Thermopsis lanceolata Robert Brown, to evaluate their effects on spruce budworm oviposition. Application of extracts from either plant on Parafilm substrate significantly deterred oviposition at dosages as low as 4.7 and 7.9 μg/cm2, respectively, in dual-choice bioassays. Of 9 quinolizidine alkaloids produced by these plants, 6 deterred oviposition on Parafilm substrate treated at 7.9 μg/cm2 or less. The most effective compounds were aloperine (0.3 μg/cm2 = 1.3 nmol/cm2), sparteine (1.6 μg/cm2 = 6.8 nmol/cm2), and cytisine (1.6 μg/cm2 = 8.4 nmol/cm2). Oviposition was deterred also on fresh host foliage, 8-cm twigs of balsam fir, Abies balsamea (L.) Miller, which had been sprayed with either a 1-ml aliquot of alkaloid extract (10 mg/ml) of S. alopecuroides or 1 ml of an aloperine solution (1 mg/ml). There was no effect on longevity of males or females continuously exposed to artificial substrate treated with aloperine or alkaloid extract from S. alopecuroides in no-choice bioassays, nor was the ability of males to inseminate females affected. However, female production of egg masses was inhibited, although clutch size (eggs per egg mass) was not affected. These results are the 1st demonstration of the behaviorally deterring and physiologically inhibiting effects of quinolizidine alkaloids on lepidopteran oviposition.
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Aphids (Aphis cytisorum) which infest broom plants (Cytisus scoparius) accumulate up to 500 µg alkaloid/g fr. wt. The alkaloids, which are similar to those of the plants, consist of 17-oxosparteine, sparteine, 12,13-dehydrosparteine, and lupanine. Infested plants contain >50% less alkaloids than aphid-free plants. In Lupinus aphid resistance which is due to their high alkaloid content is more expressed: Whereas bitter varieties are free from aphids, only the sweet alkaloidfree plants are susceptible to aphid infestation. The accumulation of alkaloids in aphids indicates that the quinolizidine alkaloids are translocated via the phloem in legume plants. This assumption is supported by direct evidence: analysis of phloem sap from Lupinus contains up to 5 mg alkaloid whereas xylem sap is virtually free of alkaloids. The interrelationship between quinolizidine alkaloids and hervivores is discussed.
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Quinolizidine alkaloids deter the feeding of herbivores (mammals, insects, molluscs), inhibit the growth and the development of bacteria and fungi and inhibit the germination of grass seeds and lettuce. Half-maximal inhibitor concentrations fall in the range between 0.5 and 15mM (= 0.01–0.3%). The actual concentrations of lupin alkaloids in the plant are between 5–200mmol/kg, i.e. much higher than the inhibitory concentrations. Since alkaloid-free lupins have a higher incidence of herbivory and disease, we assume that the biological function of lupin alkaloids is chemical defense besides minor roles as nitrogen transport and nitrogen storage compounds.
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Experiments are described which test the hypothesis that more host-specific species of caterpillars should be less aceptable to a generalist predator than polyphagous species. Caterpillars of all species were tested in paired choice tests with the Argentine ant, Iridomyrmex humilis. Experiments were replicated ten times, videotaped and later analyzed. Brightly colored specialist species (normally considered to be aposematic) were clearly the least palatable, while more cryptic specialists were also significantly less acceptable than generalists overall. Leaf-tying species were considered separately; all were highly palatable independent of host range. The results indicate that among caterpillars that do not construct leaf shelters, those with a wide post range are more acceptable than those with a narrow host range. This is consistent with the notion that generalist predators provide selection pressure favoring narrow host range in their herbivorous prey.
Article
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Quinolizidine alkaloids formed in the leaves of Lupinus albus L. are translocated via the phloem to the other plant organs, especially the maturing fruits. Compared with amino-acid transport in the phloem, the alkaloids contribute about 8% to the overall nitrogen being exported from the leaf. Since it is likely that the alkaloids are subsequently degraded in the target tissues a minor role of quinolizidine alkaloids might be nitrogen transport. A marked diurnal fluctuation of alkaloids was observed in the leaves, the phloem sap, the roots and the fruits with an increase during the day and an amplitude of several hundred percent thus providing evidence for a rapid turnover of endogenous alkaloids.
Chapter
Plants, as well as other organisms, are composed of chemical substances. In 1891, the pioneer of cytochemistry, A. Kossel, subdivided plant components into primary and secondary ones. Mothes (1980, 1984) quotes from an 1896 lecture of Kossel, who addressed the Berlin Physiological Society (in liberal translation from the German): The search and description of those atomic complexes, which are the essence of life are the foundation for the investigation of the life processes. I propose to call the essential components of the cell PRIMARY and those that are not found in all the cells that have the capacity to develop, SECONDARY. The decision whether a substance is a primary or a secondary one is in some cases difficult.
Article
Coloration, position and movements on the plants, feeding activity, and the importance of host plant alkaloids are described. Larvae are distasteful to predators. -from Authors
Chapter
The biochemistry and physiology of quinolizidine alkaloids is reviewed with respect to their role in lupin metabolism. Minor roles of the alkaloids may be nitrogen transport and nitrogen storage, but their main function is that of chemical defense. Alkaloid concentrations in the plant are in the same order or even higher than the inhibitory concentrations against pathogens that have been established experimentally. Alkaloid-free lupins are highly susceptible to herbivore predation, which shows that the alkaloids are obviously important for the survival of a lupin plant.
Article
Toxic chemicals and nutrients are often positively correlated within and among plants. We studied how such correlations affect the suitability of plants as food for herbivores by assessing the growth and survivorship ofSpodoptera eridania (army worm) on artificial diets containing lupine alkaloids and casein. We found that (1) the effects of casein were determined by other dietary components: increased dietary casein led to increased larval growth only when the diet was also high in wheat germ. (2) Dietary alkaloids were effective at very low concentrations, reducing both growth and survivorship. The alkaloids lupanine and sparteine were not synergistic in their effects, and the interaction between alkaloids and casein was significant only in the low-wheat-germ diets. (3) The effects of casein and alkaloids were generally apparent only in the first instar, and the growth of fifth-instar larvae was unaffected by diet. (4) Using these artificial diet experiments, we can make simple predictions about the food quality of plants grown under various nutrient regimes. These predictions are consistant with recent ideas about optimal plant defenses.
Article
HOST selection in aphids seems to occur mainly after alightment but little is known, apart from the probing response, of the stimuli or receptors involved1,2. In an investigation of a natural population of Acyrthosiphon spartii (Koch.) on broom (Sarothamnus scoparius L.) over 3 years, adults were observed to change their feeding sites as the seed pods enlarged and this coincided with the movement of the alkaloid sparteine between various plant organs. As the petals fell many adults and some fourth instar aphids left the stems and leaves and moved on to the pods where feeding and reproduction recommenced. This movement was not a result of overcrowding because at that time there was adequate surface area on the stems and leaves.
Article
Pyrrolizidine alkaloids (PA) have been identified in six species of Arctiidae reared on Senecio and Crotalaria. These include senecionine, seneciphylline, integerrimine, jacobine, jacozine, jacoline, jaconine and a metabolite (C15H25NO5) from Senecio, and monocrotaline, trichodesmine and crispatine from Crotalaria.The all-red aberration of Tyria jacobaeae (var. conyi) contained much less of the metabolite than normal examples of this species. Female Spilosoma lutea reared on the same plants of S. jacobaea contained markedly more jacobine and jacoline than die males.Host plant relationships and secondary plant substances are discussed. It is suggested that the Arctiid moths' own deterrent secretions, directed against vertebrate predators, pre-adapts them for feeding on foliage likewise protected against large herbivores by toxic secondary plant substances such as cardenolides and pyrrolizidine alkaloids. These latter substances are more toxic to vertebrate than to insect herbivores, and their dual function of deterrent and insect aphrodisiac puts a premium on their sequestration and storage once a species has achieved the initial steps, and occupied the plant niche concerned. It is further suggested that the polyphagous habits of the Arctiidae result in a more equitable distribution of die secondary plant substances within the Mullerian complex concerned, thus providing a generalized warning message for the potential vertebrate predator.
Article
Colorado populations of herbaceous perennial lupines show three distinct patterns of amounts, kinds, and individual variability of inflorescence alkaloids. These patterns, interpreted as alternative chemical defense strategies, can be related to the susceptibility of populations to attack by larvae of a small flower-feeding lycaenid butterfly, Glaucopsyche lygdamus. In situations ecologically unfavorable to G. lygdumus, lupine populations have “low” alkaloidal profiles, accumulating relatively low amounts of single, bicyclic alkaloids in their inflorescences, with little individual alkaloidal variability, Lupine populations which are quite available to G. lygdamus, on the other hand, accumulate much higher amounts of inflorescence alkaloids. Of these alkaloidally “high” populations, those which suffer only minor predation by G. lygdamus have individually variable mixtures of three or four inflorescence alkaloids, which are found to be isomers of lupanine and closely related tetracyclic compounds. In contrast, those which suffer heavy predation by G. lygdamus show a mixture of nine diverse alkaloidal components including lupanine, hydroxylupanine, and hydroxylupanine esters which is quite invariant from individual to individual. It is hypothesized that individual variability in alkaloids is an anti-specialist chemical defense mechanism. Such individual variability may be advantageous to plant populations by reducing the possibility of selection for strains of specialist herbivores capable of detoxifying or otherwise withstanding plant defensive compounds.
Article
The narrow host range of insect herbivores is noted, and some of the reasons why specificity has evolved are reviewed. Works indicating the need for new approaches are pointed out including the possibility that generalist predators provide a suitable pressure. Experiments to test the hypothesis that generalists are more vulnerable than specialists to predators are described. They involved a vespid wasp and over thirty species pairs of caterpillars, matched for size and density. Overall, generalists were taken more readily than specialists: some but not all reasons could be detected. The results are discussed in ecological and evolutionary terms.
Article
We examined the effects of nitrogen nutrition and defoliation on the alkaloids, nitrogen levels, and growth of Lupinus succulentus by growing plants under five nitrogen/defoliation treatments: 1) fertilization with a high-nitrate nutrient solution, 2) fertilization with a low-nitrate solution, 3) inoculation with N-fixing bacteria but without available soil nitrogen, 4) high-nitrate solution plus periodic partial defoliation, and 5) low-nitrate plus defoliation. In the absence of defoliation, plants from both the N-fixing and high-N treatments had higher concentrations of alkaloids and nitrogen, and higher growth rates than the low-N plants. Periodic defoliation had little effect on the high-N plants, but defoliated N-fixing plants were severely stunted and had lower alkaloid and nitrogen levels. The experimental treatments also affected the relative concentrations of the alkaloids. Our results indicate that 1) alkaloid composition and concentration in L. succulentus are determined by both nitrogen availability and developmental state, 2) plants relying solely on N-fixation respond quite differently to defoliation than those with adequate soil nitrogen, and 3) the food value of the plant tissue can be affected by an interaction between the effects of defoliation and nitrogen status.
Article
Alkaloid profiles of extracts of fourteen papilionaceous species in the tribes Thermopsideae and Genisteae (sensu Polhill) have been determined. Altogether, eighteen quinolizidine alkaloids, representative of four structural groups, and one dipiperidine alkaloid were identified among the legumes studied. The chemotaxonomic implications of these data are discussed.
Poisonous alkaloids in the body tissues of the garden tiger moth (Arctia caja L.) and the cinnabar moth (Tyria (=Callimorpha)jacobaeae L.) (Lepidoptera)
  • R T Aplin
Biomass and nitrogen budgets during larval development ofLymantria dispar andChoristoneura fumiferana: Allometric relationships
  • M E Montgomery
The distribution of secondary compounds within plants Herbivores: Their Interaction with Secondary Metabolites
  • N Mckey
The strange fate of pyrrolizidine alkaloids Perspectives in Chemoreception and Behavior
  • D Schneider
Chemical ecology of quinolizidine alkaloids Allelochemicals: Role in Agriculture and Forestry
  • M Wink
Poisonous alkaloids in the body tissues of the garden tiger moth (Arctia caja L.) and the cinnabar moth (Tyria (=Callimorpha)jacobaeae L.) (Lepidoptera), pp. 579?595
  • R T Aplin
  • M Androthschild
  • R.T. Aplin
Aposematism ofUresiphita reversalis larvae (Lepidoptera: Pyralidae)
  • E A Bernays
  • C B Andmontllor
  • E.A. Bernays
The distribution of secondary compounds within plants
  • N Mckey
  • N. McKey
Quinolizidine alkaloids of the Leguminosae: Structural types, analysis, chemotaxonomy, and biological activities
  • A D Kinghorn
  • M F Andbalandrin
  • A.D. Kinghorn