Chromosome-level genome assembly of the aster leafhopper (Macrosteles quadrilineatus) reveals the role of environment and microbial symbiosis in shaping pest insect genome evolution

Leafhoppers comprise over 20,000 plant-sap feeding species, many of which are important agricultural pests. Most species rely on two ancestral bacterial symbionts, Sulcia and Nasuia, for essential nutrition lacking in their phloem and xylem plant sap diets. To understand how pest leafhopper genomes evolve and are shaped by microbial symbioses, we completed a chromosomal-level assembly of the aster leafhopper's genome (ALF; Macrosteles quadrilineatus). We compared ALF's genome to three other pest leafhoppers, Nephotettix cincticeps, Homalodisca vitripennis, and Empoasca onukii, which have distinct ecologies and symbiotic relationships. Despite diverging ~155 million years ago, leafhoppers have high levels of chromosomal synteny and gene family conservation. Conserved genes include those involved in plant chemical detoxification, resistance to various insecticides, and defence against environmental stress. Positive selection acting upon these genes further points to ongoing adaptive evolution in response to agricultural environments. In relation to leafhoppers' general dependence on symbionts, species that retain the ancestral symbiont, Sulcia, displayed gene enrichment of metabolic processes in their genomes. Leafhoppers with both Sulcia and its ancient partner, Nasuia, showed genomic enrichment in genes related to microbial population regulation and immune responses. Finally, horizontally transferred genes (HTGs) associated with symbiont support of Sulcia and Nasuia are only observed in leafhoppers that maintain symbionts. In contrast, HTGs involved in non-symbiotic functions are conserved across all species. The high-quality ALF genome provides deep insights into how host ecology and symbioses shape genome evolution and a wealth of genetic resources for pest control targets.

Comparative metatranscriptomics reveals effect of host plant on microbiota gene expression of Anastrepha obliqua (Diptera: Tephritidae) larvae

The microbiota associated with phytophagous insects perform several functions that help insects exploit plant resources. Thus, microorganisms contribute to the dispersal of phytophagous species to new host plants, thereby promoting diversification. In this study, metatranscriptomic analysis was used to compare the gene expression of the microbiome of Anastrepha obliqua Macquart larvae feeding on 3 of its host plants: Spondias purpurea L (red mombin), Mangifera indica L (mango), and Averrhoa carambola L (starfruit). To identify differential gene expression in relation to the host plant, transcript abundance was compared. The results of the taxonomic and functional beta-diversity analysis showed that there were significant differences in the structures and activities of the microbial communities depending on the infested plant. Among the microorganisms, bacteria and fungi were active components of the microbiota. Differential expression analyses showed that the different active genes in each of the plants analyzed were mainly grouped into categories related to carbohydrate and amino acid metabolism, with some of these genes coding for cytochrome o ubiquinol oxidase, cytochrome c, and the enzyme isocitrate dehydrogenase. The microbiota of A. carambola larvae differed more at the level of community structure and gene function, possibly due to the different nutritional composition of the A. carambola and the presence of a set of secondary metabolites specific to the family Oxalidaceae. In conclusion, the transcriptional activity of the microbiota of A. obliqua larvae is influenced by diet, which is important because it could influence the performance of the insect on each of its different host plants.

High promiscuity among females of the invasive pest species Drosophila suzukii

Drosophila suzukii (Matsumura, 1931), the spotted-wing drosophila, is a highly invasive fruit fly that spread from Southern Asia across most regions of Asia and, in the last 15 years, has invaded Europe and the Americas. It is an economically important pest of small fruits such as berries and stone fruits. Drosophila suzukii speciated by adapting to cooler, mountainous, and forest environments. In temperate regions, it evolved seasonal polyphenism traits which enhanced its survival during stressful winter population bottlenecks. Consequently, in these temperate regions, the populations undergo seasonal reproductive dynamics. Despite its economic importance, no data are available on the behavioural reproductive strategies of this fly. The presence of polyandry, for example, has not been determined despite the important role it might play in the reproductive dynamics of populations. We explored the presence of polyandry in an established population in Trentino, a region in northern Italy. In this area, D. suzukii overcomes the winter bottleneck and undergoes a seasonal reproductive fluctuation. We observed a high remating frequency in females during the late spring demographic explosion that led to the abundant summer population. The presence of a high degree of polyandry and shared paternity associated with the post-winter population increase raises the question of the possible evolutionary adaptive role of this reproductive behaviour in D. suzukii.

Identification of Candidate Chemosensory Gene Families by Head Transcriptomes Analysis in the Mexican Fruit Fly, Anastrepha ludens Loew (Diptera: Tephritidae)

Insect chemosensory systems, such as smell and taste, are mediated by chemosensory receptor and non-receptor protein families. In the last decade, many studies have focused on discovering these families in Tephritidae species of agricultural importance. However, to date, there is no information on the Mexican fruit fly Anastrepha ludens Loew, a priority pest of quarantine importance in Mexico and other countries. This work represents the first effort to identify, classify and characterize the six chemosensory gene families by analyzing two head transcriptomes of sexually immature and mature adults of A. ludens from laboratory-reared and wild populations, respectively. We identified 120 chemosensory genes encoding 31 Odorant-Binding Proteins (OBPs), 5 Chemosensory Proteins (CSPs), 2 Sensory Neuron Membrane Proteins (SNMPs), 42 Odorant Receptors (ORs), 17 Ionotropic Receptors (IRs), and 23 Gustatory Receptors (GRs). The 120 described chemosensory proteins of the Mexican fruit fly significantly contribute to the genetic databases of insects, particularly dipterans. Except for some OBPs, this work reports for the first time the repertoire of olfactory proteins for one species of the genus Anastrepha, which provides a further basis for studying the olfactory system in the family Tephritidae, one of the most important for its economic and social impact worldwide.

Sugar alcohols have the potential as bee-safe baits for the common wasp

BACKGROUND

Pest insects are often baited with poisoned feeding stimulants, the most common of which are sugars. However, sugars are attractive for most animal species, which makes it difficult to target only a specific pest insect species. Here, we assessed different sugar alcohols for their potential as more species-selective feeding stimulants for pest insects.

RESULTS

We tested the attractiveness of the sugar alcohols sorbitol, xylitol and erythritol with a capillary feeder assay in wasps (as potential pest insects, because introduced wasps are a pest in many regions) and bees (as non-target insects). For the common wasp (Vespula vulgaris), sorbitol and xylitol acted as nutritive feeding stimulants, and erythritol acted as a non-nutritive feeding stimulant. For the buff-tailed bumble bee (Bombus terrestris), sorbitol acted as a feeding stimulant, while for the honey bee (Apis mellifera), none of the sugar alcohols acted as feeding stimulant.

CONCLUSION

The species-specific preferences for sugar alcohols suggest their potential as species-selective insect baits. The wasp-specific preference for xylitol suggests its potential as a bee-safe alternative to sugar-containing bait for controlling the common wasp. © 2022 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Protein and phytohormone profiles of Mahanarva spectabilis salivary glands infesting different forages

Given the importance of pastures for feeding cattle, the study of factors that affect their productivity is essential to get plant material of higher nutritional quality. Thus, the study of insect-plant interaction is important for the development of control strategies. Pasture spittlebugs affect forage grasses causing severe damage. We tested hormone and protein profiles differentially expressed in the salivary glands of Mahanarva spectabilis when fed with different pasture genotypes. The LC/MS approaches combined with bioinformatics tools were used to identify the mains biological processes in the salivary glands. The grouping revealed a greater number of proteins involved in biological processes of metabolic synthesis, biotic/abiotic stress, and ion transport across the membrane. The proteomic profiles were altered when insects were fed with different grasses. We also detected phytohormones in the salivary glands involved in the modulation of defense responses in host plants. These results allowed the analysis of important biological processes such as cell homeostasis, stress proteins, nucleic acid metabolism, regulation of muscle contraction, and transport and export of biomolecules. This represents an important advance in the understanding of the plant-pest interaction and can contribute to the choice of target elicitors, which allow effective strategies in the control of pasture spittlebugs.

A Hybrid Artificial Intelligence Model for Aeneolamia varia (Hemiptera: Cercopidae) Populations in Sugarcane Crops

Sugarcane spittlebugs are considered important pests in sugarcane crops ranging from the southeastern United States to northern Argentina. To evaluate the effects of climate variables on adult populations of Aeneolamia varia (Fabricius) (Hemiptera: Cercopidae), a 3-yr monitoring study was carried out in sugarcane fields at week-long intervals during the rainy season (May to November 2005-2007). The resulting data were analyzed using the univariate Forest-Genetic method. The best predictive model explained 75.8% variability in physiological damage threshold. It predicted that the main climatic factors influencing the adult population would be, in order of importance, evaporation; evapotranspiration by 0.5; evapotranspiration, cloudiness at 2:00 p.m.; average sunshine and relative humidity at 8:00 a.m. The optimization of the predictive model established that the lower and upper limits of the climatic variables produced a threshold in the population development rate of 184 to 267 adult insects under the agroecological conditions of the study area. These results provide a new perspective on decision-making in the preventive management of A. varia adults in sugarcane crops.

Sublethal Exposure Effects of the Neonicotinoid Clothianidin Strongly Modify the Brain Transcriptome and Proteome in the Male Moth Agrotis ipsilon

Simple Summary

Insect pest management relies mainly on neurotoxic insecticides, including neonicotinoids such as clothianidin. Low doses of insecticides can stimulate various life traits in target pest insects, whereas negative effects are expected. We recently showed that treatments with different low doses of clothianidin could modify behavioral and neuronal sex pheromone responses in the male moth, Agrotis ipsilon. In this study, we showed that clothianidin disrupted 1229 genes and 49 proteins at the molecular level, including numerous enzymes of detoxification and neuronal actors, which could explain the acclimatization in pest insects to the insecticide-contaminated environment.

Abstract

Insect pest management relies mainly on neurotoxic insecticides, including neonicotinoids such as clothianidin. The residual accumulation of low concentrations of these insecticides can have positive effects on target pest insects by enhancing various life traits. Because pest insects often rely on sex pheromones for reproduction and olfactory synaptic transmission is cholinergic, neonicotinoid residues could indeed modify chemical communication. We recently showed that treatments with low doses of clothianidin could induce hormetic effects on behavioral and neuronal sex pheromone responses in the male moth, Agrotis ipsilon. In this study, we used high-throughput RNAseq and proteomic analyses from brains of A. ipsilon males that were intoxicated with a low dose of clothianidin to investigate the molecular mechanisms leading to the observed hormetic effect. Our results showed that clothianidin induced significant changes in transcript levels and protein quantity in the brain of treated moths: 1229 genes and 49 proteins were differentially expressed upon clothianidin exposure. In particular, our analyses highlighted a regulation in numerous enzymes as a possible detoxification response to the insecticide and also numerous changes in neuronal processes, which could act as a form of acclimatization to the insecticide-contaminated environment, both leading to enhanced neuronal and behavioral responses to sex pheromone.

Gene Sequences of Potential Targets of Insecticidal PF2 Lectin Identified from the Larval De Novo Transcriptome of the Mexican Bean Weevil (Zabrotes Subfasciatus; Boheman 1833)

Simple Summary

The Mexican bean weevil Zabrotes subfasciatus is a major insect pest of stored beans. We have previously reported that the PF2 lectin, which is a protein found in the desert wild legume Olneya tesota (Palo Fierro), is toxic to Z. subfasciatus by inhibiting its early larval development. The use of proteomic means allowed us to identify PF2 targets in the midgut of Z. subfasciatus larvae. However, efforts to completely elucidate the insecticidal mechanism of PF2, as well as novel potential targets for insecticidal compounds, have been hindered by the lack of available genomic and proteomic information of non-model insects. Therefore, in this work we massively sequenced and analyzed the transcripts expressed in the larval stage of Z. subfasciatus, which is the first transcriptome reported for this insect. A total of 29,029 transcript sequences were identified, of which 30 sequences encode putative targets of PF2. The functional characteristics and biochemical, biological, or molecular roles for 15,124 sequences were established by means of bioinformatics tools. This study significantly increased the available genetic resources for Zabrotes and related insect species and will be helpful for any kind of future study that requires information on genes or protein sequences.

Abstract

The available genomic and proteomic information of non-model organisms is often underrepresented in public databases hindering their study at molecular, cellular, and physiological levels. Information on Zabrotes subfasciatus (Mexican bean weevil) is poorly represented in databases, yet it is a major pest of common beans. We report the transcriptome of Z. subfasciatus larvae; transcripts were sequenced using an Illumina RNA-Seq technology and assembled de novo identifying 29,029 unigenes with an average size of 1168 bp and an N50 value of 2196 bp. About 15,124 unigenes (52%) were functionally annotated and categorized. Further analysis revealed 30 unigene sequences encoding putative targets of the insecticidal PF2 lectin. The complete deduced amino acid sequences of eight selected proteins potentially related to insecticidal mechanism of Palo Fierro 2 (PF2) were used for predicting probable N-glycosylation sites and analyzing phylogenetic relationships with insect sequences. This work provides a dramatic increase in the genetic resources available for Coleopterans and set the basis for developing future studies on biological aspects and potential control strategies for Z. subfasciatus.

The Diapause Lipidomes of Three Closely Related Beetle Species Reveal Mechanisms for Tolerating Energetic and Cold Stress in High-Latitude Seasonal Environments

During winter insects face energetic stress driven by lack of food, and thermal stress due to sub-optimal and even lethal temperatures. To survive, most insects living in seasonal environments such as high latitudes, enter diapause, a deep resting stage characterized by a cessation of development, metabolic suppression and increased stress tolerance. The current study explores physiological adaptations related to diapause in three beetle species at high latitudes in Europe. From an ecological perspective, the comparison is interesting since one species (Leptinotarsa decemlineata) is an invasive pest that has recently expanded its range into northern Europe, where a retardation in range expansion is seen. By comparing its physiological toolkit to that of two closely related native beetles (Agelastica alni and Chrysolina polita) with similar overwintering ecology and collected from similar latitude, we can study if harsh winters might be constraining further expansion. Our results suggest all species suppress metabolism during diapause and build large lipid stores before diapause, which then are used sparingly. In all species diapause is associated with temporal shifts in storage and membrane lipid profiles, mostly in accordance with the homeoviscous adaptation hypothesis, stating that low temperatures necessitate acclimation responses that increase fluidity of storage lipids, allowing their enzymatic hydrolysis, and ensure integral protein functions. Overall, the two native species had similar lipidomic profiles when compared to the invasive species, but all species showed specific shifts in their lipid profiles after entering diapause. Taken together, all three species show adaptations that improve energy saving and storage and membrane lipid fluidity during overwintering diapause. While the three species differed in the specific strategies used to increase lipid viscosity, the two native beetle species showed a more canalized lipidomic response, than the recent invader. Since close relatives with similar winter ecology can have different winter ecophysiology, extrapolations among species should be done with care. Still, range expansion of the recent invader into high latitude habitats might indeed be retarded by lack of physiological tools to manage especially thermal stress during winter, but conversely species adapted to long cold winters may face these stressors as a consequence of ongoing climate warming.

First draft genome assembly of the desert locust, Schistocerca gregaria

Background: At the time of publication, the most devastating desert locust crisis in decades is affecting East Africa, the Arabian Peninsula and South-West Asia. The situation is extremely alarming in East Africa, where Kenya, Ethiopia and Somalia face an unprecedented threat to food security and livelihoods. Most of the time, however, locusts do not occur in swarms, but live as relatively harmless solitary insects. The phenotypically distinct solitarious and gregarious locust phases differ markedly in many aspects of behaviour, physiology and morphology, making them an excellent model to study how environmental factors shape behaviour and development. A better understanding of the extreme phenotypic plasticity in desert locusts will offer new, more environmentally sustainable ways of fighting devastating swarms. Methods: High molecular weight DNA derived from two adult males was used for Mate Pair and Paired End Illumina sequencing and PacBio sequencing. A reliable reference genome of Schistocerca gregaria was assembled using the ABySS pipeline, scaffolding was improved using LINKS. Results: In total, 1,316 Gb Illumina reads and 112 Gb PacBio reads were produced and assembled. The resulting draft genome consists of 8,817,834,205 bp organised in 955,015 scaffolds with an N50 of 157,705 bp, making the desert locust genome the largest insect genome sequenced and assembled to date. In total, 18,815 protein-encoding genes are predicted in the desert locust genome, of which 13,646 (72.53%) obtained at least one functional assignment based on similarity to known proteins. Conclusions: The desert locust genome data will contribute greatly to studies of phenotypic plasticity, physiology, neurobiology, molecular ecology, evolutionary genetics and comparative genomics, and will promote the desert locust's use as a model system. The data will also facilitate the development of novel, more sustainable strategies for preventing or combating swarms of these infamous insects.

First draft genome assembly of the desert locust, Schistocerca gregaria

Background: At the time of publication, the most devastating desert locust crisis in decades is affecting East Africa, the Arabian Peninsula and South-West Asia. The situation is extremely alarming in East Africa, where Kenya, Ethiopia and Somalia face an unprecedented threat to food security and livelihoods. Most of the time, however, locusts do not occur in swarms, but live as relatively harmless solitary insects. The phenotypically distinct solitarious and gregarious locust phases differ markedly in many aspects of behaviour, physiology and morphology, making them an excellent model to study how environmental factors shape behaviour and development. A better understanding of the extreme phenotypic plasticity in desert locusts will offer new, more environmentally sustainable ways of fighting devastating swarms. Methods: High molecular weight DNA derived from two adult males was used for Mate Pair and Paired End Illumina sequencing and PacBio sequencing. A reliable reference genome of Schistocerca gregaria was assembled using the ABySS pipeline, scaffolding was improved using LINKS. Results: In total, 1,316 Gb Illumina reads and 112 Gb PacBio reads were produced and assembled. The resulting draft genome consists of 8,817,834,205 bp organised in 955,015 scaffolds with an N50 of 157,705 bp, making the desert locust genome the largest insect genome sequenced and assembled to date. In total, 18,815 protein-encoding genes are predicted in the desert locust genome, of which 13,646 (72.53%) obtained at least one functional assignment based on similarity to known proteins. Conclusions: The desert locust genome data will contribute greatly to studies of phenotypic plasticity, physiology, neurobiology, molecular ecology, evolutionary genetics and comparative genomics, and will promote the desert locust's use as a model system. The data will also facilitate the development of novel, more sustainable strategies for preventing or combating swarms of these infamous insects.

Range-Expansion in Processionary Moths and Biological Control

Global climate change is resulting in a wide range of biotic responses, including changes in diel activity and seasonal phenology patterns, range shifts polewards in each hemisphere and/or to higher elevations, and altered intensity and frequency of interactions between species in ecosystems. Oak (Thaumetopoea processionea) and pine (T. pityocampa) processionary moths (hereafter OPM and PPM, respectively) are thermophilic species that are native to central and southern Europe. The larvae of both species are gregarious and produce large silken 'nests' that they use to congregate when not feeding. During outbreaks, processionary caterpillars are capable of stripping foliage from their food plants (oak and pine trees), generating considerable economic damage. Moreover, the third to last instar caterpillars of both species produce copious hairs as a means of defence against natural enemies, including both vertebrate and invertebrate predators, and parasitoids. These hairs contain the toxin thaumetopoein that causes strong allergic reactions when it comes into contact with human skin or other membranes. In response to a warming climate, PPM is expanding its range northwards, while OPM outbreaks are increasing in frequency and intensity, particularly in northern Germany, the Netherlands, and southern U.K., where it was either absent or rare previously. Here, we discuss how warming and escape from co-evolved natural enemies has benefitted both species, and suggest possible strategies for biological control.

N-glycosylation Site Analysis Reveals Sex-related Differences in Protein N-glycosylation in the Rice Brown Planthopper (Nilaparvata lugens)

Glycosylation is a common modification of proteins and critical for a wide range of biological processes. Differences in protein glycosylation between sexes have already been observed in humans, nematodes and trematodes, and have recently also been reported in the rice pest insect Nilaparvata lugens Although protein N-glycosylation in insects is nowadays of high interest because of its potential for exploitation in pest control strategies, the functionality of differential N-glycosylation between sexes is yet unknown. In this study, therefore, the occurrence and role of sex-related protein N-glycosylation in insects were examined. A comprehensive investigation of the N-glycosylation sites from the adult stages of N. lugens was conducted, allowing a qualitative and quantitative comparison between sexes at the glycopeptide level. N-glycopeptide enrichment via lectin capturing using the high mannose/paucimannose-binding lectin Concanavalin A, or the Rhizoctonia solani agglutinin which interacts with complex N-glycans, resulted in the identification of over 1300 N-glycosylation sites derived from over 600 glycoproteins. Comparison of these N-glycopeptides revealed striking differences in protein N-glycosylation between sexes. Male- and female-specific N-glycosylation sites were identified, and some of these sex-specific N-glycosylation sites were shown to be derived from proteins with a putative role in insect reproduction. In addition, differential glycan composition between males and females was observed for proteins shared across sexes. Both lectin blotting experiments as well as transcript expression analyses with complete insects and insect tissues confirmed the observed differences in N-glycosylation of proteins between sexes. In conclusion, this study provides further evidence for protein N-glycosylation to be sex-related in insects. Furthermore, original data on N-glycosylation sites of N. lugens adults are presented, providing novel insights into planthopper's biology and information for future biological pest control strategies.

Biochemical characterization of digestive membrane-associated alkaline phosphatase from the velvet bean caterpillar Anticarsia gemmatalis

In Brazil, the use of transgenic plants expressing the insect-toxic Bacillus thuringiensis endotoxin has been successfully used as pest control management since 2013 in transgenic soybean lineages against pest caterpillars such as Helicoverpa armigera. These toxins, endogenously expressed by the plants or sprayed over the crops, are ingested by the insect and bind to receptors in the midgut of these animals, resulting in disruption of digestion and lower insect survival rates. Here, we identified and characterized a membrane-associated alkaline phosphatase (ALP) in the midgut of Anticarsia gemmatalis, the main soybean defoliator pest in Brazil, and data suggested that it binds to Cry1Ac toxin in vitro. Our data showed a peak of ALP activity in homogenate samples of the midgut dissected from the 4th and 5th instars larvae. The brush border membrane vesicles obtained from the midgut of these larvae were used to purify a 60 kDa ALP, as detected by in-gel activity and in vitro biochemical characterization using pharmacological inhibitors and mass spectrometry. When Cry1Ac toxin was supplied to the diet, it was efficient in decreasing larval weight gain and survival. Indeed, in vitro incubation of Cry1Ac toxin with the purified ALP resulted in a 43% decrease in ALP specific activity and enzyme-linked immunosorbent assay showed that ALP interacts with Cry1Ac toxin in vitro, thus suggesting that ALP could function as a Cry toxin ligand. This is a first report characterizing an ALP in A. gemmatalis.

Novel Peptidase Kunitz Inhibitor from Platypodium elegans Seeds Is Active against Spodoptera frugiperda Larvae

A novel Kunitz-type inhibitor from Platypodium elegans seeds (PeTI) was purified and characterized. The mass spectrometry analyses of PeTI indicated an intact mass of 19 701 Da and a partial sequence homologous to Kunitz inhibitors. PeTI was purified by ion exchange and affinity chromatographies. A complex with a 1:1 ratio was obtained only for bovine trypsin, showing a K_i = 0.16 nM. Stability studies showed that PeTI was stable over a wide range of temperature (37-80 °C) and pH (2-10). The inhibitory activity of PeTI was affected by dithiothreitol (DTT). Bioassays of PeTI on Spodoptera frugiperda showed negative effects on larval development and weight gain, besides extending the insect life cycle. The activities of digestive enzymes, trypsin and chymotrypsin, were reduced by feeding larvae with 0.2% PeTI in an artificial diet. In summary, we describe a novel Kunitz inhibitor with promising biotechnological potential for pest control.

The mitochondrial genome of the western bean cutworm, Striacosta albicosta (Lepidoptera: Noctuidae)

The complete 15,553 bp mitochondrial genome of the western bean cutworm, Stricosta albicosta, (Lepidoptera: Noctuidae) was assembled from paired end Illumina HiSeq2500 read data. Annotation showed 13 predicted protein coding genes (PCGs), 22 tRNAs and 2 rRNAs have an order and orientation typical of insect mitochondrial genomes, and the derived rearrangement of tRNA-Met, -Ile and -Gln upstream of nad2 as in other Lepidoptera. A 79.3% A + T content resulted in a bias for codons with A or T in the 3rd position, and prevalence of synonymous substitutions suggest the effects of purifying selection on the mitochondrial genome sequence. Two microsatellite repeat motifs, (CA)₁₀(AT)₁₉ and (AT)₁₂, are respectively located in intergenic spaces between tRNA-Glu and -Phe and tRNA-Leu and 16S rRNA. Mitochondrial phylogenomics was able to resolve sub-families within the Noctuidae, and suggest analogous analyses may be applicable across other lepidopteran Families.

Antimicrobial, insecticidal and phytotoxic activities of Cotinus coggyria Scop. essential oil (Anacardiaceae)

The essential oil of Cotinus coggyria Scop.' leaves was found to be rich in α-pinene (43.1%), limonene (21.3%) and β-myrcene (8.5%). In the antimicrobial screening, essential oil was notably active on Staphylococcus aureus ATCC 29213, S. aureus ATCC BAA-977, Candida albicans ATCC 14053 and C. parapsilosis ATCC 22019 using the disc diffusion and volatilisation assays. The fumigant assay of the essential oil caused 70% and 100% mortality on the two pest adults of Acanthoscelides obtectus and Tribolium castaneum at 80 μL L⁻¹ air concentration at 96 h, respectively. In the toxicity assay on weeds, a dose-dependent decrease was observed in the germination and seedling growth of Silybum marianum and Portulaca oleracea. The present results indicated that oil could be suggested as an effective biocontrol agent in various fields.