The transfer of conidia of Metarhizium anisopliae between tsetse flies Glossina morsitans and the effects of fungal inoculation on mating and blood meal feeding behaviors were investigated in the laboratory. Male or female flies were inoculated with fungal conidia ("donors") and allowed to pair with fungus-free mate of opposite sex ("recipients") at 1-day-interval up to three mates. Fungus-treated male or female "donor" flies as well as their mates "recipients" died from fungal infection. However, mortality in male "recipient" flies declined with successive mating, from 82.5 to 32.5 %. Fungus-treated males readily located female flies and mating was successful in most cases comparable to the controls. There were no significant differences (P > 0.05) in mean duration of mating, number of jerking movements between fungus-treated and fungus-free males for all the mating lines, except in the number of jerking movements when male flies mated with the 3rd line female flies. Fungus-treated and fungus-free female flies previously mated with treated and non-treated males showed refractoriness during subsequent pairings. The number of fertile female flies was higher (P < 0.05) in fungus-free than in fungus-treated treatments, thus producing more pupae. High concentration of fungus (3.0 × 10(6) conidia ml(-1)) significantly (P < 0.05) reduced blood meal intake of flies. This study has shown that fungal infection does not affect the mating behavior of tsetse flies and fly-to-fly contamination does occur during matings. These are important attributes if entomopathogenic fungi have to be used in auto-dissemination strategy and be integrated into sterile insect technique.
The results of the monitoring of Thysanoptera species on cultivated plants in Slovenia (2000–2001),
Croatia (1994–1996), and Serbia and Montenegro (1988–2003) are presented in this study. The aim of the
investigation was to study the host plant distribution of the predator Aeolothrips intermedius Bagnall and its
potential prey. Banded thrips were found on 30 different host plant species belonging to 16 botanical families,
always in mixed populations with phytophagous or facultative phytophagous insects (including 18 Thysanoptera species). On the vegetative parts of the cultivated plants, banded thrips were found less numerous in spite of the massive population of some harmful thrips species. This indicates highly important role of pollen as alternative food for Aeolothrips intermedius.
The biology of barley shoot fly Delia flavibasis was studied using resistant (Dinsho and Harbu) and susceptible (Holker) barley cultivars at Sinana Agricultural Research Center, Ethiopia. A higher number of eggs was laid on Holker (17 eggs/female) than on Dinsho (11 eggs/female) or Harbu (12 eggs/female). However, there were no differences between cultivars in preoviposition and total reproductive periods. The shortest time required to complete larval, pupal and total developmental stages from egg to adult emergence occurred when the insect was reared on the cultivar Holker. Pupal weight, adult emergence and adult longevity did not differ between cultivars. The female to male sex ratio was 1:1. This study enabled us to understand the duration of each of the life stages of D.
flavibasis, which will undoubtedly aid researchers and growers to design a sustainable management strategy against barley shoot fly.
This study estimates the efficacy of an attract-and-kill (A&K) technique to control the horse chestnut leaf miner, Cameraria ohridella Deschka and Dimic (Lepidoptera, Gracillariidae), an invasive insect pest of the horse chestnut, Aesculus hippocastanum L. (Hippocastanaceae). The A&K formulation was dispensed as 50 μl droplets of paste-like matrix, containing C. ohridella sex pheromone, (8E,10Z)-tetradeca-8,10-dienal (85% + pure; 0.16% w/w) and a fast acting contact toxicant, pyrocides (94% pure; 6% w/w), applied directly to the bark of the trees. It was tested in 2003 at rates of 30 and 45 droplets/tree at the Ostrobramska site and at rates of 30, 60 and 90 droplets/tree at the Woloska site in Warsaw, Poland, for the first insect generation. A set of untreated plots (0 droplets/tree) was established at each site as well. The treatment efficacy was estimated using two indices: (1) moth catches in pheromone traps and (2) the number of mines per leaf. Trap catches were significantly higher in the untreated plots than in the treated plots regardless of the application rate in all sites. However, there were no significant differences in leaf damage amongst all plots on each site. At the "Lazienki Krolewskie" park the attractiveness of two types of pheromone sources were compared: traps were baited with rubber septum lures or with A&K droplets. The catches of C. ohridella in traps baited with lures were lower than captures in A&K droplet-baited traps, but the difference was not significant. Possible reasons for the low efficacy of the A&K method in management of C. ohridella and reducing leaf damage are discussed.
The present studies were carried out to evaluate resistance in the populations of Spodoptera litura Fab. (Lepidoptera, Noctuidae) from five districts of Hunan Province in China to various insecticides from 2010 to 2012 using a standard leaf dip bioassay method. For organophosphates and pyrethroids, resistance ratios compared with a susceptible Lab-BJ strain were in the range of 14-229-fold for organophosphates and 12-227-fold for pyrethroids. Similarly, relative low levels of resistance to emamectin, indoxacarb, and chlorfenapyr were observed in all five populations. In contrast, the resistance to carbamates (thiodicarb or methomyl) was significantly higher than that of organophosphates, pyrethroids and newer chemistry insecticides. The pairwise correlation coefficients of LC50 values indicated that the newer chemistry insecticides and old generation insecticides were not significant except abamectin, which was negatively significantly correlated with methomyl. A significant correlation was observed between thiodicarb, methomyl, and deltamethrin, whereas resistance to bifenthrin showed no correlations with resistance to other insecticides except deltamethrin. The results are discussed in relation to integrated pest management for S. litura with special reference to management of field evolved resistance to insecticides.
Carboxylesterases (CEs) are important enzymes that catalyze biological detoxification, hydrolysis of certain pesticides, and metabolism of many esterified drugs. The development of inhibitors for CE has many potential uses, including increasing drug lifetime and altering biodistrubution; reducing or abrogating toxicity of metabolized drugs; and reducing pest resistance to insecticides. In this review, we discuss the major classes of known mammalian CE inhibitors and describe our computational efforts to design new scaffolds for development of novel, selective inhibitors. We discuss several strategies for in silico inhibitor development, including structure docking, database searching, multidimensional quantitative structure activity analysis (QSAR), and a newly-used approach that uses QSAR combined with de novo drug design. While our research is focused on design of specific inhibitors for human intestinal carboxylesterase (hiCE), the methods described are generally applicable to inhibitors of other enzymes, including CE from other tissues and organisms.
The effects of two polyphenolic flavonoids (flavanone naringenin and flavonol quercetin) on development, fecundity, and mortality of the pea aphid, Acyrthosiphon pisum Harris (Hemiptera: Aphididae), were determined in vitro, on an artificial diets. Also determined in vitro (DC EPG method), on sucrose-agarose gels, were the effects of flavonoids on the probing and feeding behavior of adult apterae. When added to a liquid diet, higher concentrations of studied flavonoids increased the developmental time, the pre-reproductive period, and mortality and decreased fecundity and the intrinsic rate of natural increase of A. pisum. In most events associated with stylet activity (as indicated by EPG waveform g-C), differences in probing behavior did not statistically differ between the control gel and those with flavonoids; quercetin at 10, 100, and 1,000 µg cm(-3) prolonged the number of gel penetrations; and quercetin only at 10,000 μg cm(-3) prolonged the time the first g-C waveform was observed. Addition of flavonoids to the gels generally reduced passive ingestion from fluids of the gels (EPG waveform g-E2). At higher concentrations (>1,000 µg cm(-3)) the flavonoids completely stopped salivation (EPG waveform g-E1) and passive ingestion from fluids of the gels (EPG waveform g-E2). In events associated with active ingestion (EPG waveform g-G), however, differences in feeding behavior did not statistically differ between the control gel and those with flavonoids. The present findings demonstrate detrimental effects of the flavanone naringenin and flavonol on the behavior of the pea aphid. This can be employed in a biotechnological projects for plant breeding resistant to herbivores, including aphids.
Two liquid and one dry pre-commercial release spinosad formulations were evaluated at the labeled rate of 1 ppm against five stored-grain insect species on wheat, short-grain rice, long-grain rice, and maize. Except on maize, efficacy of spinosad was compared with a currently registered grain protectant, chlorpyrifos-methyl (3 ppm) plus deltamethrin (0.5 ppm). The 7- and 14-day mortalities of the lesser grain borer, Rhyzopertha dominica, were 99.0-100.0% on spinosad and chlorpyrifos-methyl plus deltamethrin-treated wheat, short-grain rice, and long-grain rice. Adult progeny of R. dominica after 42 days on these commodities decreased by 99.7-100.0% relative to progeny production on untreated wheat. Mortality and reduction in adult progeny of the rice weevil, Sitophilus oryzae, on the three commodities, and that of the maize weevil, Sitophilus zeamais, on maize and the red flour beetle, Tribolium castaneum, on wheat were 100.0% only with chlorpyrifos-methyl plus deltamethrin. The liquid spinosad formulations were most effective against the Indianmeal moth, Plodia interpunctella, on maize and wheat. Except for R. dominica, the effectiveness of spinosad on the other species varied with the formulation, exposure time, and commodity. Chlorpyrifos-methyl plus deltamethrin was effective against insect species on the commodities tested.
Die beiden DinitrocarbazolprparateF 113 U undF 114 der Firma SCHERING, Berlin, wurden in Laboratoriumsund Flugkfigversuchen auf ihre Giftwirkung gegen die Biene geprft.
1. Die LD 50 fr 22 C liegt bei etwa 0,75 mg Gift pro Biene.2. Vergiftungserscheinungen: Starke Unruhe, unbeholfene Bewegungen der Beine, vor allem des letzten Beinpaares. Noch flugfhige Tiere fliegen auergewhnlich schnell in unregelmigen Kurven. Gesteigerte Stechlust. Typisch fr die Todesstelung: Flgel nach unten abgespreizt, das letzte Beinpaar nach hinten gerade abgestreckt.3. Das Mittel wirkt nicht als Kontaktgift.4. Das Prparat zeigt im Ftterungsversuch stark abschreckende Wirkung auf die Biene.5. Ein Flugkfigversuch besttigt die nach den Ergebnissen der Laboratoriumsversuche zu erwartende Ungefhruchkeit des Mittels fr die Bienen.
1. Die LD 50 fr 22 C liegt hher als 3 mg Gift pro Biene.2. Vergiftungserscheinungen: hnlich denen, die beiF 113 U-vergifteten Bienen zu beobachten sind. Dasselbe gilt fr die Todeshaltung.3. Das Mittel zeigt keine Kontaktgiftwirkung.4. Im Ftterungsversuch bt das Prparat eine nur schwach abschreckende Wirkung aus.5. Flugkfigversuche lassen das Mittel als bienenungefhrlich erscheinen und stehen somit im Einklang mit den Ergebnissen der Laboratoriumsprfungen.
The effect of 14 soybean genotypes (Sahar, Sari, Williams, Tellar, Hill, Clark, Tms, Dpx, Zane, 032, 033, L17, Ks3494 and I27) on life history and fecundity of two-spotted spider mite (TSSM), Tetranychus urticae Koch, was investigated. All experiments were conducted at 28±1°C, 65±5% r.h. and a photoperiod of L16:D8h. The highest
development time was 8.41 and 8.78 days for male and female on I27, and the lowest value of this period was obtained on Sahar
and Ks3494 for male and female, respectively (7.11 and 7.60 days, respectively). The TSSM fecundity varied from 33.62 to 153.82
eggs per female, which was minimum on 032 and maximum on L17. The comparison of TSSM biological parameters on different soybean genotypes and cluster analysis of these parameters demonstrated
that Ks3494, 032, Dpx and Sahar were the most resistant genotypes to this pest. An antibiosis process could be, at least in
part, the cause of this variation. Knowledge of the extent of susceptibility or resistance of genotypes and biology of a pest
on a crop are fundamental components of integrated pest management (IPM) programs for any crop. Implication of these observations
in the control of TSSM on soybean is discussed.
In a study of the parasitoid complex of the locust leaf miner Phyllonorycter robiniella (Clemens, 1859), 23 species of its parasitoids were recorded at 18 localities in Serbia. The parasitoid species included 2 species of the family Braconidae, 1 of the family Eupelmidae, and 20 of the family Eulophidae. The recorded species of parasitoids are polyphagous; in addition to Ph. robiniella, they also develop on other species of leaf miners as primary; primary and secondary; or primary, secondary, and tertiary parasitoids. Among the recorded species of parasitoids, the most significant were the species Pholetesor bicolor, Pholetesor nanus, Sympiesis sericeicornis, Sympiesis acalle, Minotetrastichus frontalis, Pediobius saulius, and Baryscapus nigroviolaceus. The parasitoids were found to have a strong effect on the abundance of Ph. robiniella because they reduced more than 50% of its larvae and pupae in the majority of study samples.
In Belgium, the current distribution and abundance of Xylosandrus germanus (Coleoptera, Scolytidae), a relatively new species to the Belgian fauna, is poorly known. Therefore, data on the range and population levels of this ambrosia beetle, on a regional and local scale respectively, are presented. Based on those results, the beetles range is discussed. Among the analysed biotic and abiotic factors that could influence the species settlement and population levels, climatic ones, and temperature in particular, seem to exert a crucial influence.
Trissolcus manteroi (Hymenoptera, Scelionidae) was supplied from Aelia rostrata Boh. (Hemiptera: Pentatomidae) egg batch from Gölbaşı-Ankara, Turkey. The host and the male of T. manteroi are the new records for the world fauna. Male description was given and diagnostic characters were photographed by using
scanning electron and stereoscopic microscopes.
Numerous occurrence of Echinothrips americanus Morgan, 1913, a relatively newly established pest in European greenhouses, on a wide spectrum of cultivated plants throughout
Slovakia has encouraged us to present current data on its food ecology. Analysing 1,650 plant species, the poinsettia thrips
was found on 106 species (48 families) including 19 showing sporadic, 75 moderate and 17 high infestation. Larvae were detected
on 25 plant taxa from 13 families, most of them being new hosts. Mature clusters of Acalypha hispida, showing moderate to high infestation level and carrying both larvae and adults, were selected for more detailed statistical
evaluation. Preference of adults for upper and lower leaf surface tends to be without statistical significance, the larvae
on the contrary were strongly related to the lower side (Pearson’s χ2=13.3552, P=0.0013). Concerning the age, increased occurrence was apparent on younger leaves for both larvae and adults. For larvae
the nonparametric test gives the statistical difference between three age categories of leaves with the following values:
Kruskal–Wallis χ2=6.6384, P=0.03618. The statistical significance of age seems to be more crucial for younger shoots, as proved by the statistics for
both larvae (Kruskal–Wallis χ2=8.4852, P=0.0144) and adults (Kruskal–Wallis χ2=7.1049, P=0.0287). Different food preferences of larvae and adults may result in specific approach when applying an effective biological
or chemical control. Narrower tolerance of larvae could make them more manageable target in plant protection instead of efforts
to control the whole thrips population.
KeywordsHost plant-Food ecology-Ornamentals-Pest-Greenhouse
Liriomyza huidobrensis (Blanchard) (Diptera: Agromyzidae) is an important pest in cucumber greenhouses in Izmir, Western Turkey. This study was carried out during the spring and autumn seasons of 1999 and 2000 in two adjacent cucumber greenhouses, each 1,000m2 in size. Population densities of adult L. huidobrensis in insecticide-treated and non-treated greenhouses were compared by using yellow sticky traps. Ten traps were placed in the non-treated greenhouse and ten traps in the insecticide-treated greenhouse. Yellow sticky traps were changed weekly and the number of flies counted in order to compare the two greenhouses. In addition to monitoring the leaf miner population, in each greenhouse 100plants were checked and the ratio of infested plants, the ratio of infested leaves per plant and the number of mines per leaf were recorded weekly. The population density of the leaf miner was almost the same in both insecticide-treated and non-treated greenhouses. Thus, it was concluded that using yellow sticky traps will be healthier and more cost effective than using pesticides. Furthermore using pesticides is risky for the environment and the use of yellow sticky traps can easily reduce the number of pesticide applications. If yellow sticky traps are used in the greenhouse in a completely isolated environment and the appropriate insecticide is used when it is necessary, this will provide successful and integrated management against L. huidobrensis.
1. Getreide-Krankheiten und -Schdlinge sind von groer Bedeutung fr die Trkei. Sie verursachen alljhrlich bedeutende Verluste.2. Es gibt verschiedene Einlagerungsmethoden von Getreide in der Trkei. In den letzten Jahren wurden moderne Speicher und Silos gebaut.3. Viele Arten von Schadinsekten verursachen in der Trkei im lagernden Getreide groe Verluste.4. Der Vorratsschutz in der Trkei ist erst in den Anfngen.5. Der Getreide-Einkauf, die Einlagerung, die Belieferung der Mhlen mit Getreide und der Verkauf und Export von Getreide sind Aufgaben der Trkischen Getreide-Direktion.6. Im Jahre 1953 wurden in Istanbul einige neue Insektizide gegen verschiedene Getreideschdlinge erprobt.7. Brauchbar erwiesen sich folgende Prparate:A. Zur Entwesung leerer Speicher: Hygan Spezialpuder, verstrkt; Gammexane-Emulsion-Konzentrat; Fumite; Gammapoudre 100.B. Zur Entwesung von lagerndem Getreide: Hygan Spezialpuder; Hortexpuder; Versuchsmittel Hoe 2649.C. Begasungsmittel: Tetrakil; Phostoxin.
The insecticidal activities of the extracts, fractions, and pure compound of Sterculia foetida (L.) seeds were investigated against three major stored product pests, namely, Sitophilus oryzae (L.), Callosobruchus chinensis (L.), and Tribolium castaneum (H.), through contact and fumigation bioassay. Responses varied with test chemicals, insect species, exposure times, and
doses individually. The biologically active constituent of the S. foetida seeds was characterized as a cyclopropene fatty acid structurally elucidated as (2n-octylcycloprop-1-enyl)-octanoic acid (I) by spectroscopic analysis. The filter paper application of, (2n-octylcycloprop-1-enyl)-octanoic acid (I) at 0.2mg/cm2 caused 100% mortality to all test insects 2days after treatment (2 DAT). Among the chromatographic fractions, only the pure
hexane-eluted fraction caused 100% mortality at 0.3mg/cm2 to S. oryzae and C. chinensis 2 DAT, while the dose required to obtain the same percentage of mortality with the crude seed extract was 0.6mg/cm2. Under all treatment conditions, T. castaneum exhibited less susceptibility, taking longer than the other insects to show symptoms of toxicity. In terms of fumigant activity,
the compounds appeared to be more effective in a vapor form against all the three insects in closed containers compared with
open containers. These results suggest that the insecticidal activities of the test compounds were attributable to contact
mode of action, although there was also significant fumigant toxicity. The results indicate that the bioactive compound isolated
from S. foetida could act as a potent insecticide against S. oryzae, C. chinensis, and T. castaneum populations.
KeywordsCyclopropene fatty acid-
Insecticidal seed treatment is an alternative method to spray and granular applications. It can protect the crop right from
germination to reproductive stage. Recurrent use of chemical insecticides destabilizes the ecosystem and enhances the development
of resistance in pest population. Use of biopesticides like neem oil (NO) is a promising one in this situation. Two field
experiments were conducted to test the efficacy of NO as a seed dresser (20mlkg−1) and the effect was compared with systemic chemical insecticides imidacloprid (7gkg−1) and carbosulfan (7gkg−1) and Pseudomonas fluorescens (10gkg−1). Field studies revealed that the neem oil 60EC (C) (NO 60EC (C)) recorded minimum population of sucking pests Leafhopper—Amrasca biguttula biguttula Ishida and Aphids—Aphis gossypii Glover (Homoptera: Cicadellidae and Aphididae), i.e., below the ETL (2 number per leaf) up to 45days after sowing and provided
better yield compared to control. Although the systemic chemical insecticide imidacloprid performed better by recording 11,280
and 11,580kgha−1 of marketable fruit yield, NO 60EC (C) also recorded about twofold increase in marketable fruit yield 11,000 and 10,620kgha−1, respectively, in 2001 and 2002 experiments. Results of this study suggest that NO could be used as a potential seed dresser
for managing sucking pests in okra.
Genetic sexing technique based on the construction of a balanced lethal strain (BLS) has been proposed for Phthorimaea operculella (Zeller). The isolation of female with T(W;Z) translocation is a fundamental step to develop such a strain. Gamma irradiation
was used to induce the requested translocations. The availability of sex-linked morphological marker is required to facilitate
the detection of such mutations. Since a visible sex-linked marker has not been found in P. operculella, the main objective of our study was therefore to determine the possibility of using sex heterochromatin body as a marker
to identify the required translocated females. The appearance of sex heterochromatin body and the analysis of sex chromosomes
in F1 females of irradiated P. operculella females were investigated. The percentage of abnormality in sex heterochromatin body in highly polyploid Malpighian tubule
nuclei was positively correlated with the applied dose. Based on the appearance of this body, three mutant lines were isolated:
elongated, small and fragmented lines. W chromosome was easily distinguished from Z chromosome when the analysis of pachytene
sex chromosome bivalents of P. operculella females was carried out. The aberrations involved in W chromosome directly influenced the appearance of sex heterochromatin
body in highly polyploid somatic cells of the isolated mutant lines. The results showed that sex heterochromatin could be
used as sex determination and cytogenetic marker in P. operculella.
The structure of the female sex-determining W chromosome was examined in wild-type females and in three mutant female lines
of the codling moth, Cydia pomonella. The mutant lines were isolated from progeny of irradiated females using the abnormal appearance of sex chromatin body in
female somatic polyploid nuclei as a cytogenetic marker. A detailed cytogenetic analysis was carried out using three different
fluorescence in situ hybridization techniques: genomic in situ hybridization (GISH), comparative genomic hybridization (CGH),
and fluorescence in situ hybridization (FISH) with the codling moth W-chromosome painting probe. The FISH techniques enabled
us to identify the W chromosome and its fragments in mitotic and meiotic chromosome complements and thus helped us to resolve
complicated W chromosome aberrations induced by irradiation.
To study the bark beetle attacks on Turkish fir stands and to determine the principle site and stand factors influencing beetle
attacks, trap log method was used in the Western Black Sea Region of Turkey. The study was carried out in ten different locations
prior to flying time in February 2003. On each experimental plot, three healthy fir trees with 30–50cm diameter and 200m
apart were cut down with a chainsaw. From each sampling tree, needles were sub-sampled for determination of specific leaf-area
and macro-nutrient concentrations. In addition, on each experimental plot, crown closure, basal-area, and stand density were
measured. To determine the bulk density and nutrient concentrations of the soil, samples were taken around trees on each plot.
The relationship between measured stand variables, the number of beetle species and beetle populations were evaluated using
correlation and stepwise multiple regression procedure. Eight different species belonging to four different families from
Coleoptera were identified in examining the trap logs. Six of these eight species (Pissodes piceae Illig., Pissodes notatus Fabr., Cryphalus piceae Ratz., Pityophthorus pityographus Ratz., Xyloterus lineatus Oliv., Pityokteines curvidens Germ.) were identified as harmful beetles (HB). The other two (Thanasimus formicarius L. and Rhizophagus dispar Payk.) were identified as predator species. The analysis showed that the total number of HB increased as the site’s slope
and needle specific leaf area increased. However, as needle N concentrations increased, HB population decreased. Increased
Ca concentration in fir needle reduced total insect attack.
Tuta absoluta is a pest native to South America that produces significant damage to tomato crops and was first detected in Europe in late
2006. Data obtained during 2008 from commercial tomato crops in which IPM was applied suggested that good pest control was
possible through the combined action of the predatory mirid bugs Macrolophus pygmaeus and Nesidiocoris tenuis and the use of selective insecticides. The aim of our study was to evaluate the lethal and sublethal side effects of three
of the insecticides most widely used to control T. absoluta on these predators: azadirachtin, spinosad and indoxacarb. Seven days after applying the treatment at the maximum recommended
field rates, the mortality produced by indoxacarb ranged from 28% for nymphs of M. pygmaeus to 77% for females of N. tenuis and were significantly higher than those produced by azadirachtin, spinosad and the control (<13%). However, indoxacarb did
not affect the number of descendants of females exposed to residues during the last days of their preimaginal development.
In contrast, spinosad significantly reduced the offspring of M. pygmaeus and azadirachtin significantly reduced the offspring of N. tenuis females. The sublethal effects of azadirachtin and spinosad on predator reproduction should therefore not be ignored. This
information could be useful when selecting the most appropriate insecticide to control T. absoluta in greenhouses and field crops in which M. pygmaeus and N. tenuis are used as biological control agents.
KeywordsInsecticide toxicity–Azadiracthin–Indoxacarb–Spinosad–Sublethal effects–Zoophytophagous predators
Leaf beetle occurrence and abundance on certain shrubs and bushes were surveyed during 2002–2003 in several natural habitats of Isparta. The 34 leaf-beetle species collected are listed and classified according to their relative percentage of the total caught and to their associated host plants. In all habitats sampled, leaf beetles showed a preference for plants from the genera Quercus and Crataegus. Some abundant species causing serious damage to their food plants are discussed.
The relative abundance and the population development of small rodents were investigated on 17 sites in Croatian forests from September 1999 through June 2003. Common snap traps were set for two or three nights along transect lines in different forest types. In 27,598 trap–nights, 2,151 specimens were trapped. Small rodents were present in up to 45% of the traps in pedunculate oak forests dominated by Quercus robur L. In common beech forests with a predominance of Fagus sylvatica L., the percentage of occupied traps reached 59%. At most sites the following species were dominant:Clethrionomys glareolus Schr., Apodemus agrarius Pall. and A. flavicollis Melch. Additionally, in a forest community of Carpino betuli-Quercetum roboris typicum R., the absolute number of small rodents was calculated by means of the standard minimum method. The minimum rodent density was observed in April 2003 with 11.63n/ha (number of specimens per hectare). The maximum was reached in March 2001 with 82.03n/ha. Near the same site, the absolute number of the small rodent population was estimated using the Y method in spring 2001 as approximately 101.34n/ha. In general, the abundance of small rodents was dependent on the forest seed crop.
Two-spotted spider mite (TSSM) and onion thrips are serious pests of potatoes in the Ardabil region (Iran). In the present
study, anthocorid species were identified in potato fields of this region during 2006 and 2007. The results of the abundance
study indicate that Orius niger (Wolff) and O. minutus (Linnaeus) are major predators of these pests in potato fields. The life table parameters of these predators were compared
when they were fed 2nd instar larvae of onion thrips or female TSSM on potato leaves. In these experiments, O. niger had a lower nymphal mortality, longer oviposition period, higher net reproductive rate (R
0), and higher intrinsic rate of natural increase (r
) when fed thrips instead of mites. O. minutus feeding on mites compare to thrips had a lower nymphal mortality, longer oviposition period, higher net reproductive rate,
and higher intrinsic rate of natural increase. Based on these results, it can be concluded that these predators could be useful
as biological agents in potato fields.
The bioefficacies of essential oil and aromatized clay powder based on the mixture of clay and essential oil extracted from
Clausena anisata were evaluated for their insecticidal activities and their effects on progeny production of Acanthoscelides obtectus. Contact toxicity assayed by coating on bean grains showed that these chemicals caused significant mortality of the test insect.
Beetle mortality was dose dependant and after 2-day exposure the aromatized clay powder was more toxic (LD50=0.069μl/g grain) than the pure essential oil (LD50=0.081μl/g grain). There was, however, a highly significant loss of toxicity after 24 and 36h following treatment with
essential oil and aromatized powder, respectively. Both aromatized clay powder and pure essential oil considerably reduced
the F1 progeny insect production. The essential oil evoked moderated repellent action and high fumigant toxicity (LC50=0.093μl/cm3) against adults of A. obtectus. These results suggest that the clay powder could be used to stabilize the essential oil to increase its efficacy for use
as an alternative to synthetic insecticides.
Caraway (Carum carvi L.) belongs to the traditional crops which have been grown in Bohemia since the end of the 19th century. Depressaria daucella (Denis and Schiffermller) and Aceria carvi Nal. are two main pests of caraway in the Czech Republic. The latter becomes a serious problem in major caraway-growing areas. So far, no effective method for its control is known. The aim of this paper is to describe the phenology of symptoms of A. carvi infestation and damage caused by this pest. Our observation revealed that although A. carvi overwinters hidden within leaves of young caraway plants, the first symptoms are usually not visible before the start of flowering. Though the initial density of the pest is low, the mite population multiplies during the season when the pest attacks plant tissues and causes development of galls on leaves and flowers. Comparison of healthy plants and plants infested by A. carvi showed that infested plants had significantly more umbels but produced far fewer seeds, and the yield of caraway was thus substantially decreased. Recommendations for crop management methods to suppress the pest are given.
The influence of variable photoperiods on the feeding activity and fecundity of Galendromus occidentalis (Nesbitt) was studied on a diet of Tetranychus urticae Koch eggs. Starved G. occidentalis females were fed T. urticae eggs under ten 24-h light:dark regimes. Half of the tests started during photophase and the other half during scotophase. T. urticae eggs that were consumed and G. occidentalis eggs that were laid were counted at the end of each photophase and scotophase in a 24h period. In general, G. occidentalis consumed more T. urticae eggs per h in the first phase of the experiment than in the second, regardless of whether the lights were on or off. In contrast to egg consumption, there were no statistical differences in the mean daily fecundity at the end of the 24-h periods. However, when the experiment was started during photophase, higher fecundity/h was encountered during scotophase than during the photophase. As a result, egg consumption rates were affected by photoperiods in both phases of the experiments. Logistic regression analysis revealed that variable photoperiods and egg consumption did not influence the fecundity of G. occidentalis.
The side effects of methoxyfenozide, indoxacarb, pyridaben, acetamiprid, azadirachtin A, spinosad, and propargite on Aphidius colemani, Aphidoletes aphidimyza, and Neoseiulus cucumeris were tested under laboratory conditions. Methoxyfenozide had low toxic effect on all three species, causing mortality after
24h in 4.4, 11.4, and 29.3% of N. cucumeris, A. colemani, and A. aphidimyza, respectively. Similarly, indoxacarb caused mortality after 24h in 11.9, 20.0, and 24.9% of A. aphidimyza, N. cucumeris, and A. colemani, respectively. In general, N. cucumeris exhibited the lowest sensitivity to all the insecticides. In contrast, A. colemani was highly sensitive to most of the tested insecticides. Methoxyfenozide was shown to significantly reduce fecundity of A. aphidimyza. In contrast, there was no effect of pure azadirachtin A on A. colemani fecundity. Results showed that both methoxyfenozide and indoxacarb would be suitable for use in the integrated pest management
(IPM) because of their low toxic effect against all of the tested model species of natural enemies.
–Insecticides–Side effect–Natural enemies
Typhlodromus pyri Scheuten (Acari, Phytoseiidae) has been reported as the most important predator of the European red mite, Panonychus ulmi (Koch) (Acari, Tetranychidae) in apple culture. However, biological data on T. pyri was insufficient on important parameters like seasonal population dynamics and within-tree and on-leaf distribution in apple orchards in the region of Meckenheim, Germany. The purpose of the present work was, therefore, to obtain experimental data on these parameters of T. pyri from 2000 to 2002 in the apple orchards in this region. The results showed that overwintered females of T. pyri reactivate and start laying eggs between late March and early April. The mean daily number of the different stages of T. pyri per leaf peaked in July each year, where it ranged between 0.92–1.68 eggs, 0.81–1.41 nymphs, 0.64–1.32 females and 0.37–0.52 males. A significantly higher number of T. pyri individuals congregated in the bottom layer of trees (0.34–0.64 individuals/leaf) than in the middle and top layers (0.23–0.38 and 0.12–0.23 individuals/leaf, respectively). We found that 91.4–94.1% of the total eggs, 89.6–91.7% larvae, 73.0–76.5% nymphs, 60.5–64.6% adult females and 52.6–55.9% adult males concentrated their activities in the inner area of the leaf surface. More than 50% of the predatory mites congregated in the bottom layer in winter. Mean total density of the overwintering females in December of 2000,2001 and 2002 ranged between 10.6–14.2 females/5cm twig in the bottom, 7.3–10.4 in the middle and 4.1–6.9 in the top layers of the apple trees. Mean total fecundity recorded over the 3 years was lowest in the overwintering generation with 31.8–37.6 eggs/female, highest in the June generation with 45.9–53.7 eggs/female, and intermediate in the August generation with 41.5–46.1 eggs/female. The overwintering generation was composed entirely of females, while the female to male ratio in the June generation was 2:1, and in the August generation 3:1. T. pyri overwinters as adult females in rough structures, cracks and crevices of twigs.
The two-spotted spider mite, Tetranychus urticae Koch, is a very polyphagous pest with a worldwide distribution. In order to appraise population growth parameters of this pest, samples of two-spotted spider mites were taken from soybean (Glycine max) fields of Moghan region, Iran in June 2007 and are reared on bean plants var. Derakhshan (Phaseolus vulgaris) in a growth chamber. The life table parameters of this pest were calculated on three commercial soybean cultivars (Zane, Hach, and L17) and one hybrid (Hob × Will) at 25 ± 1°C, 60 ± 10%RH, and 16 h photophase. The developmental times of immature stages varied from 9.69 on Hach to 9.82 days on L17, whereas the immature survival was 57–79% on Hach and Hob × Will, respectively. On average, there were 65.5, 40.8, 38.8 and 34 eggs produced per female on L17, Hach, Hob × Will and Zane, respectively. The intrinsic rate of natural increase (r
) for T. urticae on Hob × Will was the highest, whereas the values for r
ranged from 0.211 (females/female/day) on Zane to 0.292 on Hob × Will. Also, jackknife values of other life table parameters such as net reproductive rate (R
0), generation times (T), doubling time (DT), and finite rate of increase (λ) on these cultivars were estimated. Overall, the two-spotted spider mite indicated a better performance on Hob × Will than on the other soybean cultivars.
The levels of susceptibility of adult female European red mite, Panonychus ulmi (Koch) populations collected from apple orchards in Bursa region of Turkey, to acaricides, dicofol, bromopropylate and fenpyroximate
belong to two different groups and an acaricide–insecticide, amitraz, were determined by a petri leaf disk-Potter spray tower
method. When compared with the susceptible population, resistance ratios, as indicated by LC50 values, ranged from 2.2 to 11.9, 0.8 to 3.6, 1.0 to 22.5 and 0.9 to 7.9, while LC90 values varied from 1.6 to 9.8, 1.0 to 5.4, 1.0 to 47.4, 1.4 to 36.6, respectively, for amitraz, dicofol, bromopropylate and
fenpyroximate. An examination of bioassay responses showed that susceptibility was lower for fenpyroximate and bromopropylate
than for the other two compounds in the order of amitraz<dicofol. In conclusion, P. ulmi susceptibility to tested compounds varied widely from location to location.
The aim of the study was to develop a stage-structured within-patch model describing predator-prey interactions of Cheyletus eruditus (Schrank) and Acarus siro L. on stored grain. Parameterisation of the model was done using data from the literature. Due to considerable variance in these data, statistical methods were used to extrapolate the parameters. The results of the simulations were compared with the experimental control of A. siro by C. eruditus on wheat. The results indicated that all life-history studies of A. siro yielded overestimated parameters leading to an unnaturally rapid population growth of A. siro on grain. The main reason seems to be the use of high quality food (wheat germs), which considerably increased fecundity. A new model with reduced fecundity was found to correspond well with the observed dynamics in a granary. The model of C. eruditus, including parameters from different sources, produced dynamics quite similar to the observed one. A simulation of biological control under laboratory conditions, on 45g of wheat, showed that C. eruditus is able to control A. siro within the observed period. In contrast, simulation of the control in a granary showed a marked difference in comparison with the observed dynamics. The discrepancy is attributed to the effects of spatial factors, such as immigration. The predator-prey model developed here appears to be valid for the prediction of the local (within-patch) population dynamics of A. siro and C. eruditus on wheat grain at 20C and 80% RH.
The ethanol extracts obtained from both leaf and seed in the Thorn apple (Datura stramonium L.) (Solanaceae) were investigated for acaricidal, repellent and oviposition deterrent properties against adult two-spotted
spider mites (Tetranychus urticae Koch) (Acari: Tetranychidae) under laboratory conditions. Leaf and seed extracts, which were applied in 167,250 and 145,750mg/l
concentrations, respectively (using a Petri leaf disc-spray tower method), caused 98 and 25% mortality among spider mite adults
after 48h. The simple logistic regression analysis showed that the independent variable, an increase in the dose of leaf
extract was associated with a significant increase in the death rate of T. urticae females, but an increase in the dosage of seed extracts did not have a significant effect. Using probit analysis and estimating
the parameters with a confidence limit of 95%, we determined the LC50 values of leaf extract to be 70,593mg/l. According to Pearson’s χ2 test, mites showed the strongest run off to bean leaf surfaces sprayed with both leaf and seed extracts (in sub-lethal doses:
<7,500mg/l and <25,000mg/l, respectively) and moved towards surfaces that had not been sprayed with extracts. Furthermore,
repeated measures ANOVA indicated a significant difference between the number of eggs laid on unsprayed bean leaves compared
to bean leaves that were sprayed with leaf and seed extracts at sub-lethal doses, 2,500 and 25,000mg/l concentrations, respectively.
These results suggest that D. stramonium extracts could be used to manage the two-spotted spider mite.
KeywordsAcaricidal-Oviposition deterrent-Repellent-Spider mite-Thorn apple
Growers of greenhouse roses in Cyprus have recently reported failures of several acaricides against two-spotted spider mite
(Tetranychus urticae Koch). To verify the cause of these failures we evaluated the effectiveness of seven acaricides against two rose and two
cucumber spider mite populations in the laboratory. The acaricides included in our study represented the most important mode
of action groups registered for use in greenhouses on the island. Label rates of all seven acaricides (abamectin, clofentezine,
dicofol, fenbutatin oxide, fenazaquin, propargite and milbemectin—a product under registration) caused close to 100% mortality
in the cucumber populations, but significantly lower mortality in the two rose populations. Mortality never exceeded 65% in
the first rose population and 20% in the second population for any acaricide, suggesting development of resistance. The higher
frequency of acaricide applications in roses and the perennial nature of the crop, that sustains genetically similar populations
for long periods of time, may have facilitated the development of resistance. Judicious use of newer acaricides with distinct
modes of action as they become registered may help control resistant spider mite populations in roses and other ornamental
crops. Additionally, adoption of a mode of action labeling scheme of pesticides and training of growers on alternation of
products will facilitate long term sustainable spider mite management in Cypriot agriculture.
In laboratory tests, the toxicity of acaricides targeted against house dust mites was tested on five species of stored product
mites (Acarus siro, Aleuroglyphus ovatus, Carpoglyphus lactis, Lepidoglyphus destructor, and Tyroborus lini). The formulations of benzyl-benzoate, benzyl-benzoate/permethrin/pyriproxyfen, and neem were diluted in water and applied
to filter paper in an unventilated chamber. The mortality of mites was observed after 24h of exposure to acaricide-impregnated
filter paper. All of the tested acaricides were toxic to all of the mite species. There were significant differences in mortality
among the species and the acaricides. Benzyl-benzoate/permethrin/pyriproxyfen was the most effective, followed by benzyl-benzoate
and neem. L. destructor (LD50 0.01–0.11μg) was the most sensitive mite species, followed by A. siro (LD50 0.04–0.12μg), T. lini (LD50 2–21μg), A. ovatus (LD50 3–18μg), and C. lactis (LD50 4–64μg). Based on the highly toxic effects of the tested acaricides against the stored product mites, the acaricides should
be considered as a potential tool in the control of stored product mites, although next screening is necessary.
The development time, longevity, and fecundity of Dysaphis plantaginea were measured on six apple cultivars (Golden delicious, Red delicious, Renetta canada, Florina querina, Golden lasa, and Golden orange) under controlled conditions, in order to establish the life tables of D. plantaginea on the different cultivars and to evaluate the tolerance of the cultivars against this pest. The intrinsic rates of increase (r
m) were 0.07 and 0.11day−1 on F. querina and G. orange, respectively. On the other four cultivars, rates ranged between 0.22 and 0.26day−1, with the maximum value registered on G. lasa. All the biological and demographic parameters evaluated, i.e. survival of larvae (M=5.8–72.2%), mean generation time (T=14.94–20.62days), and net reproduction rate (R
=4.23–47.37), show that G. orange and F. querina are tolerant cultivars while R. delicious, R. canada, G. lasa, and G. delicious are susceptible hosts.
The olive psyllid, Euphyllura phillyreae Foerster is one of the most destructive pests on buds and flowers of olive tree (Olea europaea L.) in May when the olive growers cannot apply any insecticides against the pest. Temperature-dependent development of the
psyllid was studied at constant temperatures ranged 16–26°C. A degree-day (DD) model was developed to predict the larval emergence
using the weekly cumulative larval counts and daily mean temperatures. Linear regression analysis estimated a lower developmental
threshold of 4.1 and 4.3°C and a thermal constant of 164.17 and 466.13 DD for development of egg and larva, respectively.
The cumulative larval counts of E. phillyreae approximated by probit transformation were plotted against time, expressed as the sum of DD above 4.3°C, the starting date
when the olive tree phenology was the period of flower cluster initiation. A linear model was used to describe the relationship
of DDs and probit values of larval emergence patterns of E. phillyreae and predicted that 10, 50 and 95% emergence of the larvae required 235.81, 360.22 and 519.93 DD, respectively, with errors
of 1–3days compared to observed values. Based on biofix depends the development of olive tree phenology; the DD model can
be used as a forecasting method for proper timing of insecticide applications against E. phillyreae larvae in olive groves.
Species composition of galls on the leaves of Acer pseudoplatanus L. was analysed in 2002 in three localities: the Wolski Forest, near an urban agglomeration of Krakw, the Ojcw National Park and the Andrychw Forest District. A total of 12,013 galls were found. The galls were caused by six insect or mite species. The species composition of the galls was identical in the three localities. Artacris cephaloneus (Nalepa) was the most abundant species. The index of occurrence frequency and Agrells index of species co-occurrence were calculated. The index of occurrence frequency (F) value was highest in the case of A. cephaloneus (1.277) and the lowest value, i.e. 0.00005—both from the Wolski Forest. The highest value for Agrells index of species co-occurrence, i.e. 0.900, was found in the case of Eriophyes pseudoplatani Corti and Drisina glutinosa Giard (Ojcw National Park), and the lowest,0.050, for D. glutinosa and Coptophylla gymnaspis (Nalepa) (Wolski Forest; Andrychw FD) and for D. glutinosa and Dasineura irregularis (Bremi) (AndrychwFD).
Studies on the species composition and structure of parasitoid complex of poplar twig borer,Gypsonoma aceriana (Dup.), on poplar ornamental trees in Sofia and their role in reducing the number of this pest have been conducted during
the period 1990–1997.
Six larval parasitoids—Bracon variator Nees,Orgilus obscurator (Nees),Microdus tumidulus Nees,Apanteles erevanicus Tob. (Braconidae),Pristomerus rufiabdominalis Ucida andPristomerus vulnerator (Panz.) (Ichneumonidae) were identified. Most numerous wereM. tumidulus (41.0%),A. erevanicus (30.6%) andP. rufiabdominalis (19.1%).A. erevanicus andM. tumidulus were dominating during the different years.
The parasitoids ofG. aceriana were solitary, asB. variator is an ektoparasite, and the rest—endoparasites. They attack young host larvae and emerge at the end of the pupal stage. The
life cycle of parasitoids, that have double generation, are well synchronised with the pest development. This was expressed
in the high levels of parasitism, which in some cases reached 61.5%, and as a whole for the different generations they were
5.9–44.4%.A. erevanicus andM. tumidulus were the most important in reducing the number of the pest.
Several species of the large family of tropical plants Annonaceae have been intensely investigated over the last 20years,
mainly because of the discovery of annonaceous acetogenins. These compounds are powerful cytotoxics, with potential applications
as insecticides, antiparasitics, acaricides, fungicides, and antitumor drugs. Annona montana Macfad. (Annonaceae) grows in Santa Cruz de la Sierra, Bolivia, where an infusion of leaves is used for the treatment of
lice, influenza, and insomnia. The major acetogenins from a Bolivian collection of A. montana, annonacin (1), cis-annonacin-10-one (2), densicomacin-1 (3), gigantetronenin (4), murihexocin-B (5), and tucupentol (6), were evaluated for their antifeedant and toxic effects on Spodoptera frugiperda Smith (Lepidoptera: Noctuidae), a serious pest affecting corn crops in Argentina. All the acetogenins produced 100% mortality
during the larval or pupal stages at 100μg of treatment per gram of diet. In addition, compounds 2, 3, and 4 deterred more than 80% feeding at the same dose. Relative toxicity values of LD50 for the strongest larvicidal compounds 1, 2, and 4 were determined, indicating that the three compounds are effective natural insecticides. This is the first report on the
antifeedant and toxic effects produced by the particular type of acetogenins, the mono-THF acetogenins, on the lepidopteran
S. frugiperda. No correlation was detected between the toxicity of the mentioned compounds to larvae and the known capacity of the acetogenins
1, 2, and 4 to inhibit the NADH oxidase, indicating that the inhibition of the mitochondrial complex I is not the only cause for larval
mortality of S. frugiperda.
Plants belonging to the family Annonaceae have been commonly described in traditional medicine as remedies against head lice,
and for their insecticidal properties. Characteristic constituents from a few genera of these plants are the annonaceous acetogenins.
Fourteen annonaceous acetogenins have been isolated from our Argentine collection of the seeds of A. cherimolia. We report herein the antifeedant and insecticidal effects of nine of those acetogenins on Spodoptera frugiperda (J. E. Smith). The acetogenin squamocin, one of the major constituents of the extract, displayed toxic effects on early larval
instars when incorporated to the larval diet at a dose of 50μg per g of diet. The remaining annonaceous acetogenins tested,
itrabin, asimicin, neoanonin, cherimolin-1, cherimolin-2, almuñequin, motrilin, and tucumanin produced pupal mortality and
adult malformations leading to death, when incorporated to the larval diet at the same dose. The evaluation of indices of
food consumption, growth, and food utilization indicated that squamocin was the only tested acetogenin to produce significant
decrease in the growth rate and to reduce the efficiency with which larvae converted ingested food into biomass. All the acetogenins
produced more than 80% pupal mortality with no dependence on the position of the THF rings or the number and location of the
From an Argentine collection of Annona cherimolia and a Bolivian collection of Annona montana (Annonaceae), the acetogenins, squamocin, molvizarin, itrabin, almuñequin, cherimolin-1, annonacin, annonacin-A, densicomacin-1,
cis-annonacin-10-one and murihexocin-A, were obtained to study their toxicity against the cotton pest Oncopeltus fasciatus (Hemiptera: Lygaeidae). Topical ventral application of O. fasciatus nymphs with solutions of the mentioned acetogenins produced acute and delayed mortality.
The cedar leaf moth (CLM), Acleris undulana Walsingham, has recently become an important pest in the cedar forests in southwestern Turkey. Control has focussed on the
use of synthetic chemical pesticides, with little research having been conducted on alternative control methods. In this study,
four botanical pesticides (two commercial neem products, Neemazal-T/S® and Greeneem® oil, and two hot water plant extracts, Origanum onites L. and Pimpinella anisum L.) were evaluated for their effects against young (first–second) and older (third–fifth) instar larvae of CLM under laboratory
and field conditions. The results of larval dip bioassay in the laboratory showed that all the botanical pesticides tested
had significant larvicidal activity against both young and older instars of CLM compared to the water-treated control. Of
the botanical pesticides tested, Neemazal was the most larvicidal botanical, causing mortalities ranging from 84 to 100%,
the least effective was the P. anisum extract, but at high concentrations this extract still caused significant mortality. Results from field trials also revealed
that the botanical pesticides had larvicidal activity against CLM. Neemazal was the most larvicidal botanical, followed by
Greeneem oil then by O. onites and finally by P. anisum. Our overall results suggest that all the botanical pesticides tested are promising as larvicides against CLM, and may provide
an alternative control method that is more compatible with Integrated Pest Management programs than the use of synthetic chemical
-Cedar leaf moth-Botanical extracts-Larvicidal activity-Neem products
Antifeedant activities of the isolated chemical compounds from Ajuga nipponensis, were studied against adult of striped leaf beetles. The methanol, petroleum ether, ethyl acetate and n-butanol extracts at 1.0mg/ml, were used in this study. All four extracts exhibited more than 65 antifeedant index at 24h
and ethyl acetate extract showed significant activity against striped leaf beetles with 83.12 antifeedant index. Six compounds
and one fraction were isolated by chromatography and their structures were identified by NMR, MS and FTIR spectra. At 2.0mg/ml
for 24h the three compounds 20-hydroxyecdysone, acacetin and apigenin showed considerable activities with antifeedant indexes
59.29, 51.22 and 61.55, respectively. In contrast to this the antifeedant indexes of acacetin and apigenin, were sharply reduced
as the time extended and that of 20-hydroxyecdysone remained unchanged. In addition, the synergistic effects of two mixtures
of secondary metabolites, were studied and no sharp difference was observed.
The biological activity of essential oil extracted from coriander, Coriandrum sativum L. (Apiaceae) against eggs, larvae and adults of Tribolium castaneum (Herbst) was investigated in a series of laboratory experiments. Bioassays conducted in air-tight glass chambers showed vapour
toxicity and strong repellency on filter paper arena test towards all the stages used. Responses varied significantly (P<0.001) within insect stages, dosages and exposures. At 12.0μg/ml dosage, mortality of adults reached 95%, but for 12-,
14- and 16-days larvae, mortalities were 65, 74 and 82%, respectively. On the developmental inhibition, individuals fumigated
at the larval stage confirmed that the percentage of larvae reaching to pupal stage and pupae to adult stage, decreased significantly
(P<0.001) with increasing dosage concentration. The oil fumigation yielded 100% mortality for T. castaneum larvae, pupae and adults at 0.08μg/ml dosage. The oil had fumigant activity against eggs and the toxicity progressively
increased with increased exposure times and concentrations. One hundred per cent T. castaneum egg mortalities were obtained with oil fumigation at 20μg/ml and 96h exposure period. C. sativum oil also showed highly repellent activity to the adults of T. castaneum, with overall repellency was 90% and at a dosage of 12μg/ml repellency was 100% in a filter-paper arena test.
To reveal the multi-generation effects of transgenic Bt cotton on the metabolism of secondary target herbivores, the activities
of digestive and detoxification enzymes in beet armyworm, Spodoptera exigua (Hübner), fed with transgenic Bt (cv. GK-12) vs. non-Bt cotton (cv. Simian-3) for three successive generations were examined.
Significantly lower activities of lipase, carboxylesterase (CarE) and acetylcholinesterase (AChE), and higher activities of
trypsin and total superoxide dismutase (T-SOD) were observed in Bt-fed S. exigua than in non-Bt fed individuals during the three generations. But the activity of amylase did not differ between the Bt-fed
and non-Bt fed S. exigua. Among the three generations of Bt-fed S. exigua, the activities of lipase and trypsin decreased significantly in the second or third generation than in the first generation.
But those of CarE and AChE were increased significantly. Among the three generations of non-Bt fed S. exigua, the activity of lipase was significantly higher in the second and third generations than in the first generation. The increasing
adaptation and fitness of S. exigua after continuous exposure to Bt cotton was supposed to be associated with the enhanced activities of detoxification enzymes.
Measuring multi-generational enzymes activities of S. exigua in response to Bt cotton can provide proofs of its adaptation development, which is suggested to be a mandatory part of risk
assessment of transgenic Bt plants on secondary target herbivores.
-Transgenic Bt cotton-Ecological risk assessment-Multi-generation-Detoxification enzyme-Digestive enzyme
Molluscicidal activity of cow urine alone and with different additives was studied against Lymnaea acuminata. The toxicity of cow urine kept for 15days in sunlight (8h/day) or ambient laboratory conditions against the snail was time- and concentration-dependent. The pH of fresh cow urine is 7.4 which changes to 10.9 when kept for 15days in laboratory; exposure to sunlight for the same period alter the pH to 10.85. Binary combinations (1:1) of freeze-dried cow urine kept for 15days separately with each of Allium sativum (Liliaceae) bulb powder, Azadirachta indica (Meliaceae) oil, Annona squamosa (Annonaceae) seed powder, Ferula asafoetida (Apiaceae) root latex and tea leaves, and Camellia sinensis (Theaceae) were more toxic to the snail than treatment with urine alone. Additives to cow urine in sunlight were more effective than those under laboratory conditions.
This study was carried out to determine the development, survival and reproduction responses of Adalia fasciatopunctata revelierei (Mulsant) (Coleoptera: Coccinellidae) feeding on Hyalopterus pruni (Geoffroy) (Homoptera: Aphididae), using 20, 40, 80, 160 and 250prey densities. All experiments were conducted at 25±1°C,
60±5% relative humidity, 16:8light:dark under laboratory conditions. The average daily prey consumption of A. fasciatopunctata revelierei immatures and adults increased with increasing prey densities. Predation was not different for the larval stages at 80, 160
and 250prey densities. The longevities of adult females were 35.67, 35.33, 49.00, 58.33 and 57.16days when 20, 40, 80, 160
and 250 H. pruni were provided, respectively. The mean daily and total fecundity of A. fasciatopunctata revelierei increased with increasing prey densities. Females of A. fasciatopunctata revelierei feeding on H. pruni laid 89eggs at 20prey density and 301.67 eggs at 160prey density. The search rate of females was higher than that of
all larval instars; and the search rate of the fourth-instar larvae was higher than that of younger instars. Handling time
decreased with development from larval stages to adult.