Andrés González Ritzel

Universidad de la República de Uruguay | UdelaR · Facultad de Química

Plant domestication by selective breeding may reduce plant chemical defense in favor of growth. However, few studies have simultaneously studied the defensive chemistry of cultivated plants and their wild congeners in connection to herbivore susceptibility. We compared the constitutive glycoalkaloids (GAs) of cultivated potato, Solanum tuberosum, a...

Forest plantations in Uruguay have doubled in the past decade, with Eucalyptus spp. leading this growth. The bronze bug, Thaumastocoris peregrinus (Heteroptera: Thaumastocoridae), originally restricted to Australia, is an important emerging pest of Eucalyptus plantations in the Southern hemisphere. T. peregrinus feeds on mature Eucalyptus leaves, c...

Cryptoblabes gnidiella Milliére (Lepidoptera: Pyralidae) is an economically important exotic pest of vineyards in Southern Brazil and Uruguay. The sex pheromone of C. gnidiella was identified as a mixture of (Z)-11-hexadecenal and (Z)-13-octadecenal, and has been used to monitor populations of this pest in Israel. The development of mating disrupti...

Epinotia aporema (Walsingham) is a Neotropical pest of legumes in southern South America. Its importance has increased during the last decade owing to the significant growth of soybean production in the region. Monitoring of E. aporema is difficult due to the cryptic behavior of the larvae, and hence, chemical control is carried out preventively. W...

The arctiid moth Utetheisa ornatrix is protected against predation by pyrrolizidine alkaloids (PA) that it sequesters as a larva from its food plant. Earlier work had shown that males transmit PA to the female with the sperm package and that the female bestows part of this gift on the eggs, protecting these against predation as a result. We now sho...

The targeted pollination strategy has shown positive results in directing honey bees to crop flowers offering nectar along with pollen as reward. Kiwifruit is a functionally dioecious species, which relies on bees to transport pollen from staminate to pistillate nectarless flowers. Following the targeted pollination procedures recently validated, w...

Plant-herbivore interactions have been extensively studied in tomato plants and their most common pests. Tomato plant chemical defenses, both constitutive and inducible, play a role in mediating these interactions. Damaged tomato plants alter their volatile profiles, affecting herbivore preferences between undamaged and damaged plants. However, pre...

Herbivorous insects assess and choose their potential host plants based on traits that may correlate with host suitability or quality. These traits may operate as cues for better resources, noxious chemicals, or fewer competitors and enemies. Interactions between insects and their host plants may also be modulated by the nutritional value of the pl...

Almond is a high-market value crop that benefits from honeybee pollination services, even for self- compatible varieties. Besides, it has been recently shown that the offering of food scented with floral mimic odors specific to different crops biased honeybee foraging preferences towards sunflowers, pear, or apple trees. Herein, we analyzed the flo...

Eucalyptus species are among the most planted trees in forestry production, an ever-increasing commercial activity worldwide. Forestry expansion demands a continuous search for preventive and sanitary measures against pests and diseases. Massive application of phytosanitary products is incompatible with the forestry sector, so forest health managem...

Plant-herbivore interactions have been extensively studied in tomato plants and their most common pests. Tomato plant chemical defenses, both constitutive and inducible, play a role in mediating these interactions. Damaged tomato plants alter their volatile profiles, affecting herbivore preferences between undamaged and damaged plants. However, pre...

The ability of herbivorous insects to discriminate suitable host plants for the devel- opment of their progeny is not homogenous. Herbivores with broader diets show weaker correlation between oviposition preference and offspring performance in comparison with specialist insects. The neural constraints hypothesis postulates that due to neural limita...

The plantation and natural forests of South America have been highly impacted by native and exotic pests in recent decades. The interaction of emerging invasive pests, climate change, and timber markets will define the region's forests, with significant but uncertain ecological changes and economic losses expected. The Southern Cone Forest Health G...

Biological control may benefit from the behavioral manipulation of natural enemies using volatile organic compounds (VOCs). Among these, herbivore-induced plant volatiles (HIPVs) provide potential tools for attracting or retaining predators and parasitoids of insect pests. This work aimed to characterize the VOCs emitted by pear plants in response...

While chemical control is still the primary strategy for insect pest management in fruit production, alternative strategies such as biological control need to be incorporated. Biological control may benefit from the behavioral manipulation of natural enemies using volatile organic compounds (VOCs). Among these, herbivore-induced plant volatiles (HI...

Thorough and systematic surveys of host associations of Anastrepha fraterculus and Ceratitis capitata are lacking in Uruguay. Our aim was to establish the host status in field conditions and the pattern of use of different fruit species in agroecosystems and wild environments in Uruguay. Tephritid monitoring was conducted in citrus and deciduous fr...

Biological control is an alternative strategy to control Cacopsylla bidens. The aim of this study was to untanglethe trophic network involving C. bidens as prey. Molecular techniques along with predator activity surveys were employed to evaluate predation on psylla. Feeding on C. bidens was detected for five predators: Chrysoperla externa, Chrysopi...

Caracterización de la feromona sexual de Spodoptera frugiperda (Lepidoptera: Noctuidae) en Argentina y ensayos de campo.

Since Drosophila suzukii (Diptera: Drosophilidae; SWD) became a worldwide pest of soft-skinned fruits, multiple mitigation strategies alternative to insecticides have been explored. Among these, the search for biological control agents has prompted the assessment of drosophilid parasitoids for SWD control. Olfactometer bioassays with drosophilid pa...

The citrus borer, Diploschema rotundicolle, is a South American cerambycid beetle considered a primary citrus pest in Uruguay. Serious focalized population explosions have been registered in recent years, particularly in lemon orchards. The larvae feed on the woody tissue, causing tree deterioration and reducing grove productivity and value. Curren...

The subfamily Cerambycinae, one of the most diverse in longhorn beetles, is well known for its remarkable chemical parsimony in male-emitted pheromones. Conserved shared structural motifs have been reported in numerous species, sometimes working in combination with plant volatile kairomones. Among other compounds, the most ubiquitous male pheromone...

Entomopathogenic fungi such as Beauveria bassiana are extensively used for the control of insect pests worldwide. They infect mostly by adhesion to the insect surface and penetration through the cuticle. However, some insects, such as the red flour beetle Tribolium castaneum (Herbst), have evolved resistance by embedding their cuticle with antifung...

Palpita forficifera Munroe (Lepidoptera: Crambidae) is the principal pest in olive groves in Brazil and Uruguay, damaging buds and fruits. Therefore, this work was undertaken to understand the biology of P. forficifera at different temperatures, to determine thermal requirements, and to estimate the number of annual generations in different olive g...

Biocontrol agents such as parasitic wasps use long-range volatiles and host-associated cues from lower trophic levels to find their hosts. However, this chemical landscape may be altered by the invasion of exotic insect species. The spotted-wing drosophila (SWD), Drosophila suzukii (Diptera: Drosophilidae), is a highly polyphagous fruit pest native...

The stereoselective synthesis of several components of the aggregation pheromones of numerous longhorn beetle species is described. These attractants consist in 3-hydroxy-2-alkylketones and 2,3-alkyldiols with chain lengths varying from six to ten carbons. The 3R- and 3S-series are generated by organocatalytic α-hydroxylation of alkylketones with n...

• Semiochemicals are powerful tools for the surveillance and suppression of forest insects. Although the literature on the chemical ecology of and use of semiochemicals to manage the Cerambycidae is growing, little is known about the chemical ecology of Cerambycidae fauna in Peru. • Trapping studies that screen known attractants in off-shore mitiga...

Knowledge of the reproductive ecology of insect pests is important for the development of sustainable pest control strategies. Mating behavior studies can provide insights about relevant aspects of intra- or intersexual communication processes, which may lead to sustainable control strategies based on behavioral disruption. The bronze bug, Thaumast...

Serratia marcescens can be a plant growth promoting bacteria (PGPB) and an opportunistic human and plant pathogen. We have identified and characterized strains of related species of Serratia and evaluated their biological control of damping-off of tomato seeds caused by Pythium cryptoirregulare. Serratia ureilytica, S. bockelmannii and S. nevei wer...

Acaricides and the gut parasite Nosema ceranae are commonly present in most productive hives. Those stressors could be affecting key semiochemicals, which act as homeostasis regulators in Apis mellifera colonies, such as cuticular hydrocarbons (CHC) involved in social recognition and ethyl oleate (EO) which plays a role as primer pheromone in honey...

When developing new products to be used in honeybee colonies, further than acute toxicity, it is imperative to perform an assessment of risks, including various sublethal effects. The long-term sublethal effects of xenobiotics on honeybees, more specifically of acaricides used in honeybee hives, have been scarcely studied, particularly so in the ca...

The citrus borer, Diploschema rotundicolle, is a Neotropical longhorn beetle that has become a serious citrus pest in southern South America. Management strategies for this insect rely on trimming off damaged shoots, which is expensive and inefficient. We studied the chemical communication system in D. rotundicolle in search of attractants for moni...

Persicaria maculosa (Polygonaceae) (known as lady’s thumb) is an annual morphologically variable weed that is widely distributed in Chile. The purpose of this study was to investigate the antifeedant potential of methanolic (MeOH), ethanolic (EtOH), and dichloromethane (DCM) extracts from the aerial parts of this plant collected in the Valparaíso a...

We report for the first time the occurrence in Uruguay of three species of Anastrepha, which belong to the curvicauda species group. Specimens of Anastrepha australis (Blanchard, 1959), Anastrepha littoralis (Blanchard, 1959), and Anastrepha nigra (Blanchard, 1959) were collected with McPhail traps baited with PBX ® yeast/borax placed in fruit orch...

Carpocapsa (Cydia pomonella) es la plaga de mayor importancia de manzano y peral en Uruguay. Por ello, en los últimos años se han hecho esfuerzos tendientes a su control por métodos alternativos al uso de insecticidas, como el método de confusión sexual, en el marco del Programa de Manejo Regional de Plagas en frutales de hoja caduca. Al disminuir...

Honeybees (Apis mellifera) adjust their time and effort during foraging activity. Their metabolic rates together with body temperature rise while gathering profitable resources. These physiological changes may result in a differential cuticular profile, which in turn may bear communicational value. We evaluated if sucrose concentration of collected...

Oviposition-site selection may be greatly affected by competitive plant-mediated interactions between phytophagous insects but these interactions have been poorly investigated on trees. Here, we evaluated the potential interaction between two invasive pests of Eucalyptus trees, the red gum lerp psyllid, Glycaspis brimblecombeiMoore (Hemiptera, Ster...

Biological control is a major tool for forest insect pest management. We initiated a biological control program for the Eucalyptus bronze bug, Thaumastocoris peregrinus, with the egg parasitoid Cleruchoides noackae. Parasitized eggs were imported from a mass rearing in Brazil, and a rearing colony was set up. The wasp was reared in plastic tubes ea...

The bronze bug, Thaumastocoris peregrinus Carpintero & Dellapé (Heteroptera: Thaumastocoridae), is an exotic emerging pest in Eucalyptus commercial forests in South America, Africa, and southern Europe. Information on the chemical communication system and reproductive ecology of this insect is scant, and it may be relevant for designing management...

The bronze bug, Thaumastocoris peregrinus Carpintero & Dellape (Heteroptera: Thaumastocoridae), is an exotic emerging pest in Eucalyptus commercial forests in South America, Africa and southern Europe. Information on the chemical communication system and reproductive ecology of this insect is scant, and it may be relevant for designing management s...

In social insects, task-related recognition plays an important role in the coordination and cohesion between members of the colony. Tetragonisca angustula is an eusocial stingless bee that presents a sophisticated system of defense involving two complementary groups of guards: hovering and standing guards. We identified, quantified, and compared th...

Optimal foraging and optimal oviposition are two major forces leading to plant selection by insect females, but the contribution of these forces to the host-selection process has been little studied for sucking herbivores. We studied feeding and oviposition behavior of a global pest, the bronze bug, Thaumastocoris peregrinus Carpintero & Dellapé (H...

The synthesis of 3-hydroxy-2-hexanone and 2,3-hexanediol, two components of the aggregation pheromone of several cerambycid species, is disclosed in here. Starting from 2-hexanone, through an α-hydroxylation using (diacetoxyiodo)benzene, 3-hydroxy-2-hexanone is obtained in good yield. Further reduction of this compound, gives 2,3-hexanediol in exce...

Changes in female calling behavior in response to the presence of conspecific pheromones (pheromone autodetection) have been demonstrated in a number of moth species. However, the observed changes vary between species, and several ecological and adaptive explanations for autodetection have been proposed. We studied the effect of conspecific females...

Background: The sawfly family Pergidae is best represented in South America, and it is the third largest family in the suborder Symphyta. Tequus is a Neotropical genus that has been reported in association with host plants of the genus Solanum (Solanaceae), with little information about the life history of its members. Tequus schrottkyi (Konow, 19...

Differences in sexual signals among species are common, and may influence mate recognition and reproductive isolation. In scorpions, behavioural mechanisms and other sexual signals involved in mate selection and reproductive isolation have been scarcely studied. In this paper, we compare different male sexual signals between two distant populations...

Botanical biopesticides constitute an important tool for Integrated Pest Management practices. Uruguay has a great potential for developing botanical biopesticides from its abundant native flora. Dodonaea viscosa Jacq. is a native Sapindaceae that in preliminary studies was shown to possess a potential deterrent activity against insect models. In t...

The bronze bug, Thaumastocoris peregrinus Carpintero et Dellape (Heteroptera Thaumastocoridae), is one of the most important emerging pests of Eucalyptus LHeritier plantations worldwide. In the development of strategies to control this pest, establishing effective rearing protocols is fundamental to future research programs. We assessed life-histor...

Cryptoblabes gnidiella (Lepidoptera: Pyralidae) is a primary vineyard pest in South America and secondary fruit pest in the Mediterranean basin. The sex pheromone of C. gnidiella, a 1:1 mixture of (Z)-11-hexadecenal and (Z)-13-octadecenal, is suitable for population monitoring, but chemically unstable for population control by mating disruption. Th...

Chemical communication is an important mediator of social interactions in fish, including mate recognition, mate choice and intrasexual competi-tion. We used a simultaneous-choice design to test the response of adult females of the annual killifish, Austrolebias reicherti, towards male-condi-tioned water, both crude and fractionated into its polar...

Crocidosema (= Epinotia) aporema (Walsingham) (Lepidoptera: Tortricidae) is a bud borer that feeds on soybean and forage legumes. Its economic importance is restricted to South America, where it can alternate throughout the year between forage and grain legumes. The sex pheromone of C. aporema females is composed of a 15:1 mixture of (7Z,9Z)-dodeca...

Resumen. el incesante aumento de la población mundial demandará un esfuerzo constante por optimizar los rendimientos en la producción de alimentos. un porcentaje importante de la producción agrícola es consumida por insectos herbívoros, por lo que el manejo ambientalmente sostenible de estas especies se presenta como un desafío actual y a futuro. L...

We have investigated whether the chemical components of fetal fluids (FFs), which elicit repulsion in late gestating ewes, are also those responsible for the attractiveness of fetal fluids at parturition. An aqueous fraction of FFs (A1), obtained after extraction with hexane, was tested for repulsion in late-pregnant ewes and for attraction at part...

Ladybird beetles produce a large number of defensive alkaloids. Previous studies suggest that the structural diversity of these endogenous alkaloids can be traced to a common biosynthetic route based on the condensation of several acetate units. In this study, adults of Epilachna paenulata, a phytophagous neotropical species, were fed on diet enric...

Multitrophic interactions regulate oviposition-site selection in insects. Many plants can detect oviposition and respond to it with structural and chemical changes that negatively affect the egg (Hilker & Meiners, 2006). Volatiles emitted by egg-carrying plants may be in turn used as cues by egg predators and parasitoids to locate their hosts. Natu...

Beekeeping has always been vulnerable to various sanitary drawbacks. The mite Varroa destructor (Mesostigmata: Varroidae), an obligated ectoparasite of honeybees, has been in recent times one of the major problems leading not only to economical losses but also to ecological problems related to the role of honeybees as the most important pollinators...

A bioassay-guided fractionation of leaf extracts from Clytostoma callistegioides (Cham.) Bureau ex Griseb. (Bignoniaceae) led to isolation of a natural mixture of four fatty acids with anti-insect activity against aphids. The compounds were identified by GC-MS as palmitic, stearic, linoleic and linolenic acids and quantified as their methyl esters....

Mate finding in many spider species is mediated, at least in part, by chemical cues. Although few have been characterized, most spider sex pheromones seem to be associated with the silk threads of adult females, attracting and/or triggering sexual behaviors in males. Schizocosa malitiosa (Araneae: Lycosidae) is a wolf spider common in dry environme...

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Crocidosema aporema (Walsingham) is a major pest of legumes in the southern cone of Latin America. The mating behaviour of two allopatric populations (Uruguay and Brazil) of C. aporema kept in captivity was studied by observing the posture of calling females, the temporal pattern of pheromone emission and mating, and the response of males to callin...

We evaluated the anti-insectan activity of extracts from different vegetative parts of ten plant species native to Uruguay. The selected plants belong to five families: Bignoniaceae: Clytostoma callistegioides, Dolichandra cynanchoides, Macfadyena unguis-cati; Sapindaceae: Dodonaea viscosa, Allophylus edulis, Serjania meridionalis; Lamiaceae: Salvi...

As pesquisas com feromônios de insetos tem uma longa e rica história, construída, primariamente, pelos estudos conduzidos no hemisfério Norte. Não é surpresa que estes estudos tenham apontado, em grande parte, para espécies relevantes dessas regiões do mundo, na maioria pragas agrícolas e florestais. As investigações com feromônios nos países da Am...