Studies related to the effect of insecticides on insect pests and nontarget organisms, such as natural enemies, are traditionally accessed by the estimative of lethal effects, through mortality data. Due to the limitations of the traditional methods, recent studies in the past three decades are assessing the sublethal effects of insecticides upon several important biological traits of insect pests and natural enemies. Besides mortality, the sublethal dose/concentrations of an insecticide can affect insect biology, physiology, behavior and demographic parameters. In this chapter, many sublethal effects of insecticides were addressed for several chemical groups, such as botanical insecticides, carbamate, diamide, insect growth regulators, neonicotinoid, organochlorides, organophosphates, pyrethroid and others. An accurate assessment of these effects is crucial to acquire knowledge on the overall insecticide efficacy in the management of pest insect populations, as well as on their selectivity toward nontarget organisms.

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The effects of tangerine (Citrus reticulata Blanco), lemon (Citrus medica limonum Lush), pear orange (Citrus sinensis L. Osbeck), red copaiba (Copaifera langsdorffii Desf.), rosemary (Baccharis dracunculifolia De Candole), eucalyptus (Eucalyptus globulus Labillardière and E. citriodora Hook), lemongrass (Cymbopogon citratus Stapf.) and citronella (Cimbopogon nardus Linnaeus) oils at several concentrations on Zabrotes subfasciatus (Boheman) were studied. In toxicity tests, grains of Phaseolus vulgaris L. cv. Rajadinho were impregnated with oils and infested with adults of Z. subfasciatus up to 24 hours old. All tested oils were effective in reducing the viable egg-laying and adult emergence of this pest, in function of the concentrations used, highlighting E. citriodora and E. globulus oils which caused 100% effectiveness from 0.5 mL Kg -1 concentration. In repellency tests, two arenas consisting of plastic containers, connected symmetrically to a central box by two plastic tubes were used. In one of the boxes, untreated beans were placed and on the other ones beans treated with each oil concentration were used. In the central box, five couples of Z. subfasciatus were released. Grains of P. vulgaris treated with oils of E. citriodora, C. citratus and C. oleifera reduced the attraction percentage of Z. subfasciatus adults, while the E. globulus increased this percentage. The percentages of reduced viable eggs ranged from 17.9% (C. medica limonum) to 93.3% (C. nardus), while the reduction on the number of emerged insects was 23.9% and 95.9%, respectively for these same oils. KEYWORDS: Botanical insecticides, bean weevil, bioactivity, behavioral effect.Toxicidade e repelência de óleos essenciais a Zabrotes subfasciatus (Boheman) (Coleoptera, Chrysomelidae, Bruchinae) em grãos de Phaseolus vulgaris L. RESUMOEstudaram-se os efeitos dos óleos de tangerina 'Cravo' (Citrus reticulata Blanco), limão-siciliano (Citrus medica limonum Lush), laranja 'Pêra' (Citrus sinensis L. Osbeek), copaíba-vermelha (Copaifera langsdorffii Desf.), alecrim-do-campo (Baccharis dracunculifolia De Candole), eucalipto (Eucalyptus globulus Labillardière e Eucalyptus citriodora Hook), capim-santo (Cymbopogon citratus Stapf.) e citronela (Cymbopogon nardus L.), em diversas concentrações, sobre Zabrotes subfasciatus (Boheman). Nos testes de toxicidade, grãos de Phaseolus vulgaris L. cv. Rajadinho foram impregnados com os óleos e infestados com adultos de Z. subfasciatus com até 24 horas de idade. Todos os óleos foram eficientes na redução da postura de ovos viáveis e na emergência de adultos desta praga, em função das concentrações utilizadas, destacando-se E. citriodora e E. globulus, que a partir da concentração de 0,5 mL Kg -1 já causaram 100% de eficácia. Nos testes de repelência utilizaram-se arenas compostas por dois recipientes plásticos, interligados simetricamente a uma caixa central por dois tubos plásticos. Numa das caixas colocaram-se grãos de feijão não tratados e, na outra, feijões tratados com cada uma das concentrações de ól...

-The objective of this work was to assess the fumigant and repellent effects of essential oils on adults of Callosobruchus maculatus and to identify the chemical composition of two of the tested essential oils. For the fumigation test, the oils of Schinus terebinthifolius, Piper aduncum, Syzygium aromaticum, Piper hispidinervum, Cymbopogon citratus, Cinnamomum zeylanicum, and the eugenol compound were tested at different concentrations on C. maculatus adults. For the repellency test, the oils of S. terebinthifolius, P. aduncum, P. hispidinervum, S. aromaticum, Jatropha curcas, and Ricinus communis were evaluated. In the fumigation test, it was observed that P. aduncum and eugenol showed the highest and lowest LC 50s , of 169.50 and 0.28 µL L -1 air, respectively. In the repellency test, the oils of S. aromaticum and P. hispidinervum were repellent to C. maculatus. Gas chromatography coupled to mass spectrometry (GC-MS) analysis of these two oils identified 42 compounds, of which safrole was the main component of P. hispidinervum and eugenol of S. aromaticum. The essential oils of S. aromaticum, C. zeylanicum, and the eugenol compound are the most promising to control C. maculatus, via fumigation.

Resumo -O objetivo deste trabalho foi avaliar a preferência alimentar, o limiar de ingestão e o efeito tóxico de inseticidas associados a atrativos, em adultos de Neoleucinodes elegantalis. Foram testados os atrativos: melado e mel a 10%, extrato hexânico de frutos verdes de tomate a 0,4%, sacarose a 5%, suco de laranja e suco de uva a 30%, vinagre de vinho tinto a 10% e proteína hidrolisada a 5%. Com base no teste de preferência alimentar, foram selecionados os atrativos sacarose, melado, mel e suco de laranja, para determinar o limiar de concentração capaz de estimular a alimentação de adultos de N. elegantalis. Foi testado o efeito tóxico de inseticidas associados ao mel a 10%. A sacarose e o mel apresentaram o melhor resultado em relação ao número de pousos e ao tempo de pouso e de alimentação de adultos de N. elegantalis. Os inseticidas não afetaram negativamente a atração pelo alimento dos adultos de N. elegantalis. Carbaril, cartape, deltametrina, fenpropatrina, indoxacarbe, lambda-cialotrina e lufenurom provocaram 100% de mortalidade em adultos (machos + fêmeas), após 24 horas de exposição, e mostraram-se promissores para o uso em iscas tóxicas.Termos para indexação: Neoleucinodes elegantalis, controle comportamental, iscas tóxicas, limiar de resposta. Selection of attractive food sources and toxicity of insecticides in tomato fruit borer managementAbstract -This work aimed at evaluating the food preference, the threshold of food intake and the toxic effect of insecticides associated with attractive food sources on adults of Neoleucinodes elegantalis. The following attractive food sources were tested: molasses and honey at 10%, hexanic extract of green tomato fruits at 0.4%, sucrose at 5%, orange and grape juice at 30%, red wine vinegar at 10%, and hydrolyzed protein at 5% concentration. Based on the food preference test, sucrose, molasses, honey, and orange juice were selected to determine the threshold concentration capable of stimulating feeding in N. elegantalis adults. The toxic effect of insecticides added to honey at 10% was also tested. Sucrose and honey had the best results in terms of number of landings, landing time, and feeding time of adults of N. elegantalis. The insecticides did not affect negatively the attraction of N. elegantalis adults to the food sources. Carbaryl, cartap, deltamethrin, fenpropatrin, indoxacarb, lambda-cyhalothrin, and lufenuron caused 100% mortality of adults (males and females), after 24 hours of exposure, which suggests that they are promising for use in toxic baits.

This study had the following objectives: to identify and quantify the constituent compounds of essential oils from Cymbopogon winterianus Jowitt, Eucalyptus globulus Labill., Eucalyptus staigeriana F. Muell. ex F.M. Bailey, Foeniculum vulgare Mill., Ocimum basilicum L., Ocimum gratissimum L., and Piper hispidinervum C. DC., investigate their toxicity and repellency to S. zeamais and evaluate the toxicity of P. hispidinervum to immature S. zeamais. Individual tests for each essential oil were conducted with a completely randomized design with five concentrations for each oil and four replicates. Gas chromatography-mass spectrometry revealed the presence of citronellal in C. winterianus, 1,8-cineole in E. globulus, limonene in E. staigeriana, limonene in F. vulgare, linalool in O. basilicum, (E)-anethole in O. gratissimum, and safrole in P. hispidinervum. The median lethal concentration required to kill 50% of the insect (LC50) in contact and ingestion toxicity tests ranged from 5.12 to 78.89 μL 40g-1 corn in P. hispidinervum and C. winterianus, respectively. In adult fumigation tests, the LC50 ranged from 2.1 to 19.4 µL L-1 air, and in immature fumigation tests, the egg stage was susceptible to essential oil, whereas larval and pupal phases were tolerant. All of the oils repelled S. zeamais.

Five Zea mays cultivars (BRS Caatingueiro, BRS Gorutuba, BRS Sertanejo, BRS Asa Branca and BR 106) were evaluated considering their effect on the nutrition of the maize weevil Sitophilus zeamais, by analysis of total protein in adult fed with these cultivars and for the presence of lectins and trypsin inhibitors in grains. In addition, free-choice and no-choice assays were performed to investigate the resistance of grains of the Z. mays cultivars to an attack by S. zeamais. The BR 106 cultivar showed the lowest susceptibility index, followed by BRS Caatingueiro, BRS Asa Branca, BRS Sertanejo and BRS Gorutuba. The number of emerged adults in the Z. mays cultivars ranged from 213.17 to 74.0, and the lowest number of insects was recorded for the BR 106 cultivar. The insects were able to feed on grains of all cultivars, but the BR 106 cultivar showed the least reduction in dried biomass. Lectins were detected in extracts from BR 106, BRS Asa Branca, BRS Sertanejo and BRS Gorutuba, and the highest activity was shown by BR 106. The lowest protein assimilation was detected in the insects from treatments with BRS Asa Branca. The extracts from all cultivars were able to inhibit the activity of bovine trypsin, but this effect was not related to the resistance degree of Z. mays cultivars. The results suggest the resistance of BR 160 to the attack of S. zeamais, as well as indicating that the presence of lectin in the grains is the cause of this resistance.