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Parasitism rates and parasitoid development can be influenced by the species and developmental stage of the host, both of these factors can influence parasitoid performance and fitness. In this study, parasitism rates and developmental parameters were assessed for two widely distributed and commercially available species of aphid parasitoid: Aphidius ervi (Hymenoptera: Braconidae) and Aphelinus abdominalis (Hymenoptera: Aphelinidae). In a first bioassay, parasitism rates and parasitoid development were investigated in different host species. The wasp A. ervi was tested on Macrosiphum euphorbiae, Rhopalosiphum padi, and Myzus persicae (Hemiptera: Aphididae) and A. abdominalis was tested on M. persicae, R. padi, and Rhopalosiphum maidis (Hemiptera: Aphididae). The results indicated that A. ervi had a greater percentage of emergence, higher percentage of parasitized aphids, longer developmental time, and higher proportion of females in M. persicae than in the other hosts. A. abdominalis had a greater percentage of emergence, larger progeny, and shorter developmental time in R. padi than in the other hosts. A second bioassay evaluated the preference of the parasitoids for different instars of their respective optimum host aphids in terms of parasitism and development, as determined in the first bioassay. The results showed that A. ervi produced a greater number of mummies in the fourth instar and in adults of M. persicae. In contrast, A. abdominalis preferred the first instar of R. padi. In conclusion, our results indicate that both parasitoid species exhibit different parasitism parameters depending upon the host species and the host stage. This suggests that these parasitoid species could be potentially complementary on multiple or combined releases of biological control programs. [ABSTRACT FROM AUTHOR]

Neurotoxic insecticides are widely used for crop protection and behavioural perturbations can be expected in surviving beneficial insects, including parasitoids of pest insects. The present study aims to investigate the relationship between the dose of insecticide parasitoids have been exposed to, and the subsequent ability of these parasitoids to respond to host-related cues. A four-armed olfactometer, a design widely used to observe orientation responses in various insects and parasitoids in particular, was chosen to investigate the dose–response relationship. The species studied was Aphidius ervi, a relatively generalist parasitoid of aphids, and commercialised for biological control and integrated pest management. Active ingredients with similar and different modes of action on the nervous system were compared: a pyrethroid (lambda-cyhalothrin), an organophosphate (chlorpyrifos), a carbamate (pirimicarb) and a carbamyltriazole (triazamate). Adult females were exposed to dry residues on glass for 24 h. LD50 were calculated and predicted a high risk of mortality at the field application rate. The effect of five increasing residual doses of each active ingredient was tested on responses to plant-host odour in the olfactometer, from sublethal doses to LD50, and up to LD70 for some products. It appeared that none of the doses of lambda-cyhalothrin, chlorpyriphos and pirimicarb had any effect on A. ervi responses to the odour from the aphid-infested plant (Myzus persicae on oilseed rape). But for triazamate, a significant dose–behavioural response was quantified and attraction to the odour was no longer significant in females surviving the LD50. The possible explanations for the presence or absence of effect, depending on the insecticide are discussed. [Copyright &y& Elsevier]

The South American tomato pinworm, Tuta absoluta (Meyrick), is one of the major threats to tomato production. Larvae can cause losses of more than 80% of production. It was officially detected for the first time in West Africa in 2012, in Senegal, and was subsequently reported in most countries in this part of the continent. To identify infested vegetable production areas and determine reservoir plants in Côte d'Ivoire, surveys were carried out and pheromone traps set in the North, South, East, West and Center in the main tomato production areas of the country. The pest was detected in all surveyed areas, with the highest number of males (623 ± 19.5 insects/week) caught by pheromone traps in Bouaké in the Center of Côte d'Ivoire and a highest percentage of infested leaves, 96 ± 2.5%, was obtained in the locality of Agnibilékro in the East of the country. Tuta absoluta attacked all phenological stages of tomato plant in field. Larval mines were observed on the eggplant, Solanum melongena, the black nightshade, Solanum nigrum and the peppers, Capsicum annuum. Apart from tomato, T. absoluta seems to prefer S. melongena (41.64 ± 2.95% of infested leaves/plant; 4.88 ± 0.4 mine/plant) and S. nigrum (36.27 ± 3.42% of infested leaves/plant; 4.26 ± 0.6 mine/plant) more than C. annuum (13.48 ± 2.42% of infested leaves/plant and 1.38 ± 0.18 mine/plant). This study led to understanding that T. absoluta is well established in the main tomato production areas of Côte d'Ivoire, causing damage regardless of plant development stages and is present on other plant species. [ABSTRACT FROM AUTHOR]

In the current paper, we reviewed the use of nanoparticles (NPs) in crop protection, emphasizing the control of pests in the agricultural and urban environment. At the same time, we provide the framework on which the technology of NPs is based and the various categories of NPs that are currently used for pest control. Apart from the use of NPs as carriers of a broad category of active ingredients, including insecticides and pheromones, some NPs can be used successfully as insecticides alone. Moreover, several types of NPs are produced by natural resource-based substances, which make them promising 'green' alternatives to the use of traditional pest control agents. Finally, the potentials in the use of NPs are briefly illustrated and discussed. [ABSTRACT FROM AUTHOR]

After its arrival in 2008, the Spotted Wing Drosophila (SWD), Drosophila suzukii, has emerged as a harmful invasive insect pest in North America and Europe. This highly polyphagous pest is a major threat to many economically important fruit crops and is also known to develop on a wide variety of natural host plants. In Asia, Europe and North America, different control measures are applied against SWD, such as chemical, biological, and cultural control. Current controls of SWD rely primarily on the application of insecticides, but cultural management tactics such as sanitation and the use of nets provide a good alternative in some crops. Biological control measures, such as conservation of existing natural enemies in invaded areas, introduction of specialized larval parasitoids from Asia for classical biological control and the use of indigenous parasitoids for augmentative control, are currently being investigated and may become an important management tool in the near future for an area-wide control of SWD. [ABSTRACT FROM AUTHOR]

Plant-insect interactions are strongly modified by environmental factors. This study evaluates the influence of nitrogen fertilisation on the tomato ( Solanum lycopersicum L.) cv. Santa clara and the leafminer ( Tuta absoluta (Meyrick), Lepidoptera: Gelechiidae). Greenhouse-grown tomato plants were fed hydroponically on a complete nutrient solution containing either a high nitrogen concentration ( HN) sustaining maximum growth or a low nitrogen concentration ( LN) limiting plant growth. Insect-free plants were compared with plants attacked by T. absoluta. Seven and 14 days after artificial oviposition leading to efficacious hatching and larvae development, we measured total carbon, nitrogen and soluble protein as well as defence compounds (phenolics, glycoalkaloids, polyphenol oxidase activity) in the HN versus LN plants. Only in the HN treatment did T. absoluta infestation slightly impair leaf growth and induce polyphenol oxidase ( PPO) activity in the foliage. Neither the concentration of phenolic compounds and proteins nor the distribution of nitrogen within the plant was affected by T. absoluta infestation. In contrast, LN nutrition impaired T. absoluta-induced PPO activity. It decreased protein and total nitrogen concentration of plant organs and enhanced the accumulation of constitutive phenolics and tomatine. Moreover, LN nutrition impaired T. absoluta development by notably decreasing pupal weight and lengthening the development period from egg to adult. Adjusting the level of nitrogen nutrition may thus be a means of altering the life cycle of T. absoluta. This study provides a comprehensive dataset concerning interrelated responses of tomato plants and T. absoluta to nitrogen nutrition. [ABSTRACT FROM AUTHOR]

More than six decades after the onset of wide-scale commercial use of synthetic pesticides and more than fifty years after Rachel Carson's Silent Spring, pesticides, particularly insecticides, arguably remain the most influential pest management tool around the globe. Nevertheless, pesticide use is still a controversial issue and is at the regulatory forefront in most countries. The older generation of insecticide groups has been largely replaced by a plethora of novel molecules that exhibit improved human and environmental safety profiles. However, the use of such compounds is guided by their short-term efficacy; the indirect and subtler effects on their target species, namely arthropod pest species, have been neglected. Curiously, comprehensive risk assessments have increasingly explored effects on nontarget species, contrasting with the majority of efforts focused on the target arthropod pest species. The present review mitigates this shortcoming by hierarchically exploring within an ecotoxicology framework applied to integrated pest management the myriad effects of insecticide use on arthropod pest species. [ABSTRACT FROM AUTHOR]

The distribution and abundance of species that cause economic loss (i.e., pests) in crops, forests or livestock depends on many biotic and abiotic factors that are thought difficult to separate and quantify on geographical and temporal scales. However, the weather-driven biology and dynamics of such species and of relevant interacting species in their food chain or web can be captured via mechanistic physiologically based demographic models ( PBDMs). These models can be implemented in the context of a geographic information system ( GIS) to predict the potential geographic distribution and relative abundance of pest species given observed or climate change scenarios of weather. PBDMs may include bottom-up effects of the host on pest dynamics and, if appropriate, the top-down action of natural enemies. When driven by weather, PBDMs predict the phenology, age structure and abundance dynamics at one or many locations enabling the distribution of the interacting species to be predicted across wide geographic areas. PBDMs are able to capture relevant ecosystem complexity within a modest number of measurable parameters because they use the same ecological models of analogous resource acquisition and allocation processes across all trophic levels. The use of these analogies makes parameter estimation easier as the underlying functions are known. This is a significant advantage in cases where the biological data available to build an evidence base for pest risk assessment is sparse. [ABSTRACT FROM AUTHOR]

This study is the first step of the Tuta PI program (2011-13) to decrease the costs of Integrated Pest Management ( IPM) strategies against Tuta absoluta in France by investigating new beneficial insects. Currently, the association of predator/egg parasitoid ( Macrolophus pygmaeus and Trichogramma achaeae, respectively) in IPM strategies are quite effective, but expensive. Sixty-four new potential strains from 19 Trichogramma species originating from different regions of the world (from the collection of Trichogramma at INRA Provence Alpes Côte d'Azur ( PACA), France) were studied in this work. A screening study was performed on T. absoluta eggs on isolated tomato leaves (for 24 h at 25 ± 1°C, RH 75 ± 5% and 16 h light : 8 h dark). The proportion of parasitized T. absoluta eggs varied greatly (between 0 and 73%) depending on the different strains used. Levels of parasitism by females, equal to or higher than that of T. achaeae, were observed in 14 of the strains tested among eight species (four from France, four from elsewhere in Europe). The proportion of females that parasitized T. absoluta eggs was significantly different between strains (from 0 to 100%). Experimental results allowed about half of the 64 initial strains to be eliminated before the next steps: tests on a larger scale (mesocosm, and then in the greenhouse and field). [ABSTRACT FROM AUTHOR]