Life-History and Behavior of the Diamondback Moth Plutella xylostella on Brassicaceae Cultivars over Multiple Generations

The diamondback moth (DBM), Plutella xylostella (L.) (Lepidoptera: Plutellidae), is a cosmopolitan pest that causes leaf-area reduction in Brassicaceae plants. DBM populations have significant genetic variability that manifests in different feeding preferences and reproductive behaviors across generations. We evaluated the influence of Brassicaceae cultivars on biological and behavioral parameters across 18 generations of DBM populations that were separated and held on three varieties of Brassicaceae: Brassica oleracea var. acephala (kale), Brassica oleracea var. italica (broccoli), and Brassica oleracea var. capitata (cabbage). P, F6, F12, and F18 generations were evaluated, and biological aspects of young adulthood and fertility parameters of adults held on each host plant were examined over multiple generations. Additionally, larvae and adults were subjected to dual-choice and multiple-choice (feeding and oviposition) between cultivars, over generations. The results indicated that larvae of P. xylostella consumed greater quantities of kale and broccoli cultivars, on average (4.05 cm2), than cabbage (2.7 cm2). The number of eggs per female in F18 generation was 1.95 and 2.17 times higher than those in the parental (P) generation, when reared on kale and cabbage. The population reared exclusively on kale had higher net population growth rate (R0), intrinsic rate (rm), finite rate (λ) and generation time (T) than that reared on broccoli and cabbage. Last generations evaluated, the larval stage reared on cabbage showed feeding preference (F18) and oviposition preference (F12 and F18) for cabbage. Thus, we note the existence of learning, characterized as pre-imaginal conditioning to cabbage cultivars, over various DBM generations

Desenvolvimento de Plutella xylostella (Linnaeus, 1758) (Lepidoptera: Plutellidae) em Brassicaceae ao longo de gerações

Species of Brassicaceae family are part of the global food base. Nutritional characteristics of brassics show high levels of vitamins, fiber, minerals, phenols, flavonoids, hydroxycinnamic acid, soluble sugars, fatty acids and carotenoids, and secondary substances such as glucosinolates that are currently recognized by the antioxidant and anti-carcinogenic effects. The diamondback moth, Plutella xylostella, is one of the main limiting factors of this crop in the world, due to the serious damage that cause to plants, depreciating the product and causing serious reductions in the field production. The knowledge of the biology of this insect in different cultivars is important so that you can determine those less favorable to the pest development and reproduce. In this context, the objective of this study was to evaluate the influence of the larvae food substrate (Brassicaceae’s varieties) in the P. xylostella development over 18 generations. Insects were reared on 3 comercial varieties/cultivars of importance to the northeastern of Sao Paulo State: Brassica oleracea var. acephala - kale Manteiga hibrida HS-20, Brassica oleracea var. italica - broccoli Piracicaba and Brassica oleracea var. capitata - cabbage Bob Cat. Every 3 generations the biological aspects of P. xylostella were evaluated in laboratory trials. The biological parameters evaluated were: leaf consumption, larval period, larval viability, pupal period, pupal viability, pupal weight, sex ratio, number of eggs per female, egg fertility, and longevity of males and females. The results were analysed comparing generations and cultivars. The biological parameters of P. xylostella showed that cabbage cultivar was less consumed and the larval period was longer while the pupal period was shorter. However, the low initial performance of this cultivar was being improved over the generations, matching the others in the latest generations ...Espécies da família Brassicaceae fazem parte da alimentação básica mundial. Suas características nutricionais mostram altos teores de vitaminas, fibras, minerais, fenóis, flavonóides, ácido hidroxicinâmico, açúcares solúveis, ácidos graxos e carotenoides, além de substâncias secundárias como glucosinolatos que, atualmente, são reconhecidos pelas propriedades antioxidantes e anticancerígenas. A traça-das-crucíferas, Plutella xylostella, é um dos principais fatores limitantes deste cultivo no mundo, devido aos sérios danos que causa às plantas, depreciando o produto e ocasionando grandes perdas nos campos de produção, portanto, o conhecimento do desenvolvimento deste inseto em diferentes cultivares é importante para que se possa determinar aquelas menos propícias para o inseto. Neste contexto, o objetivo deste trabalho foi verificar se houve influência do substrato alimentar das lagartas (variedades de Brassicaceae) no desenvolvimento de P. xylostella, ao longo de 18 gerações. Os insetos foram criados em 3 variedades/cultivares de importância comercial para a região nordeste do Estado de São Paulo: Brassica oleracea var. acephala - couve Manteiga hibrida HS-20, Brassica oleracea var. italica - brócolis Piracicaba e Brassica oleracea var. capitata - repolho Bob Cat. A cada 3 gerações aspectos biológicos do inseto criado nos diferentes substratos de alimentação foram avaliados em ensaios de laboratório. As características biológicas analisadas foram: consumo foliar, período larval, viabilidade de larvas, período pupal, viabilidade de pupas, peso pupal, razão sexual, número de ovos por fêmea, fertilidade de ovos, longevidade de machos e longevidade de fêmeas. Os resultados foram submetidos a análise fatorial comparando-se gerações e cultivares. Os parâmetros biológicos de P. xylostella demonstraram que repolho foi o menos consumido e o que apresentou ..

Aspectos nutricionais e preferência da lagarta-da-soja,Anticarsia gemmatalis Hüebner, 1818 (Lepidoptera: Noctuidae) em genótipos de soja com e sem injúria

Resistance to insects can be due to chemical factors present in the plant, and, according to the nature of the compounds, the resistance may be constitutive (independent of environmental stress), or induced by stress. In the case of soybeans, there are citations of constitutive and induced resistance, and for induced resistance, the value of information produced by the plant depends, for example, on the degree of the herbivore infestation. The induced resistance due to injury caused by the feeding of caterpillars Pseudoplusia includens in soybean occurs and has its peak near the 10th day after the injury. This way, the objective of this paper was to study the influence of previous injury in soybean genotypes, �Embrapa 4� and �BR 37�, through the soybean defoliation by caterpillars, the preference and nutrition of Anticarsia gemmatalis. From the results obtained, it was possible to observe that the genotype �Embrapa 4� is preferred by the caterpillars of A. gemmatalis in relation to �BR 37�, with a much higher leaf area consumed. As for the first one, an evident induction of resistance by a prior herbivory occurs, since the tests performed after defoliation show negative influence on insect development; consumption and use of food indexes were, in general, higher also for the variety �Embrapa 4� which was not injured.A resistência ao ataque de insetos pode decor de fatores químicos presentes na planta, sendo que, conforme a natureza dos compostos, a resistência pode ser constitutiva (independente de estresse ambiental), ou induzida por estresse. No caso da soja, existem citações de resistência constitutiva e induzida, sendo que para a resistência induzida, o valor da informação emitida pela planta depende, por exemplo, do grau de infestação do herbívoro. A resistência induzida devido à injúria provocada pela alimentação de lagartas de Pseudoplusia includens em plantas de soja ocorre e tem o pico próximo ao 10º dia após a injúria. Assim, o objetivo deste trabalho foi estudar a influência da injúria prévia, nos genótipos de soja, �Embrapa 4� e �BR 37�, por meio do desfolhamento por lagartas da soja, na preferência e na nutrição de Anticarsia gemmatalis. A partir dos resultados obtidos, verifica-se que, o genótipo �Embrapa 4� é preferido pelas lagartas de A. gemmatalis em relação ao �BR 37�, com índice de área foliar consumida bem superior. Para o primeiro, ocorre evidente indução de resistência pela herbivoria prévia, uma vez que os testes realizados após a desfolha mostram influência negativa no desenvolvimento do inseto; os índices de consumo e utilização de alimento, de modo geral, foram mais elevados também para a variedade �Embrapa 4� não injuriada

FREQUÊNCIA FENOTÍPICA DE ASAS E OLHOS AO LONGO DE GERAÇÕES EM POPULAÇÕES DE LABORATÓRIO DE Chrysoperla externa (NEUROPTERA: CHRYSOPIDAE)

In massal rearing of natural enemies with the goal of biological control, the procedures adopted for establishment and maintenance of the individual founders of the colonies may have undesirable effects on population genetic structure of laboratory. This situation influences the success of rearing and effectiveness in the field. The objective of this study was to evaluate, along of generations two laboratory populations (Jaboticabal and Piracicaba) of Chrysoperla externa (Hagen) (Neuroptera: Chrysopidae), founded with different numbers of adults (1, 5, 10, 15 and 20 couples), the frequency of morphological variants, size of wings and eye color, such as parameters for inferences about the homozygosity degrees. For eye color were assessed the frequency, while for the size of wings was measured the width and the length of the right mesothoracic wings. The eye color variants for C. externa populations may be monitored in the laboratory aiming at detecting inbreeding, whereas the measurements of length and width of wings should not be adopted for this purpose

Frequência fenotípica de asas e olhos ao longo de gerações em populações de laboratório de chrysoperla externa (Neuroptera: Chrysopidae)

In massal rearing of natural enemies with the goal of biological control, the procedures adopted for establishment and maintenance of the individual founders of the colonies may have undesirable effects on population genetic structure of laboratory. This situation influences the success of rearing and effectiveness in the field. The objective of this study was to evaluate, along of generations two laboratory populations (Jaboticabal and Piracicaba) of Chrysoperla externa (Hagen) (Neuroptera: Chrysopidae), founded with different numbers of adults (1, 5, 10, 15 and 20 couples), the frequency of morphological variants, size of wings and eye color, such as parameters for inferences about the homozygosity degrees. For eye color were assessed the frequency, while for the size of wings was measured the width and the length of the right mesothoracic wings. The eye color variants for C. externa populations may be monitored in the laboratory aiming at detecting inbreeding, whereas the measurements of length and width of wings should not be adopted for this purpose.Em criações massais de inimigos naturais com o objetivo de controle biológico, os procedimentos adotados para a coleta e estabelecimento dos indivíduos fundadores e a manutenção das colônias podem ter efeitos indesejáveis sobre a estrutura genética da população de laboratório, influenciando, por sua vez, no sucesso da criação e a eficácia em campo. O objetivo deste trabalho foi avaliar ao longo das gerações de duas populações de laboratório (Jaboticabal e Piracicaba) de Chrysoperla externa (Hagen) (Neuroptera: Chrysopidae), iniciadas com diferentes quantidades de indivíduos fundadores (1, 5, 10, 15 e 20 casais), as frequências de variantes morfológicas como dimensões de asas e cor dos olhos compostos, como parâmetros para inferências sobre o aumento do grau de homozigose. Para a coloração dos olhos foram avaliadas as frequências, enquanto que para o tamanho de asas avaliou-se a maior largura e o maior comprimento da asa mesotorácica direita. As variantes para cor dos olhos compostos de C. externa podem ser monitoradas nas populações de laboratório objetivando detectar endogamia, enquanto que as medidas de comprimento e largura de asas não devem ser adotadas para tal finalidade

DURAÇÃO DO PERÍODO PRÉ-IMAGINAL E FECUNDIDADE DE Chrysoperla externa (HAGEN, 1861) (NEUROPTERA: CHRYSOPIDAE) EM DIFERENTES POPULAÇÕES E GERAÇÕES

The lacewings appear in many agroecosystems, preying several species of agricultural pests. They have great search capability, high voracity, high reproductive potential and are easily maintained in laboratory conditions. In laboratory rearing, to avoid problems in the mass production are recommended adjustments in the type and quality of prey to be used in order to obtain individuals with desirable characteristics. It is necessary special care with the laboratory populations, avoiding problems from inbreeding. Larvae were reared individually in Petri dishes (9.0 cm diameter) and fed with eggs of Sitotroga cerealella (Olivier, 1789) (Lepidoptera: Gelechiidae), in the amount of 25 mg / larva, while the adults were kept in PVC cylindrical cages (10 cm x 30 cm). Thus, the study analyzed the influence of the size of the population of Chrysoperla externa (Hagen, 1861) (Neuroptera: Chrysopidae) on the pre-imaginal period (egg to adult) and reproductive capacity of this specie come from different populations and generations of laboratory. To this end, we used two populations, one of Jaboticabal (F8 and F21) and one of Piracicaba (F6 and F15), and subpopulations of 1, 5, 10, 15 and 20 couples, analyzing the incubation of eggs and the number of eggs per female in each population, generation and subpopulation. The pre-imaginal period (egg to adult) and the number of eggs per female of C. externa are influenced by the generation and the number of founding individuals, being these parameters favored when laboratory populations are established with the largest number of couples

Aspectos nutricionais e preferência da lagarta-da-soja,Anticarsia gemmatalis Hüebner, 1818 (Lepidoptera: Noctuidae) em genótipos de soja com e sem injúria

Resistance to insects can be due to chemical factors present in the plant, and, according to the nature of the compounds, the resistance may be constitutive (independent of environmental stress), or induced by stress. In the case of soybeans, there are citations of constitutive and induced resistance, and for induced resistance, the value of information produced by the plant depends, for example, on the degree of the herbivore infestation. The induced resistance due to injury caused by the feeding of caterpillarsPseudoplusia includens in soybean occurs and has its peak near the 10th day after the injury. This way, the objective of this paper was to study the influence of previous injury in soybean genotypes, ‘Embrapa 4’ and ‘BR 37’, through the soybean defoliation by caterpillars, the preference and nutrition of Anticarsia gemmatalis. From the results obtained, it was possible to observe that the genotype ‘Embrapa 4’ is preferred by the caterpillars of A. gemmatalis in relation to ‘BR 37’, with a much higher leaf area consumed. As for the first one, an evident induction of resistance by a prior herbivory occurs, since the tests performed after defoliation show negative influence on insect development; consumption and use of food indexes were, in general, higher also for the variety ‘Embrapa 4’ which was not injured.RESUMO – A resistência ao ataque de insetos decorre de fatores químicos presentes na planta, sendo que, conforme a natureza dos compostos, a resistência pode ser constitutiva (independente de estresse ambiental), ou induzida por estresse. No caso da soja existem citações de resistência constitutiva e induzida, sendo que nesta última o valor da informação emitida pela planta depende, por exemplo, do grau de infestação do herbívoro. A resistência induzida devido à injúria provocada pela alimentação de lagartas de Pseudoplusia includens em plantas de soja ocorre e tem o pico próximo ao 10º dia após a injúria, decaindo a partir de então. Assim, o objetivo deste trabalho foi estudar a influência da injúria prévia, nos genótipos ‘Embrapa 4’ e ‘BR 37’ de soja, por meio do desfolhamento por lagartas da soja, na preferência e na nutrição de A. gemmatalis. Pelos resultados obtidos, o genótipo ‘Embrapa 4’ é preferido pelas lagartas de A. gemmatalis em relação ao ‘BR 37’, sendo que para o primeiro ocorre evidente indução de resistência pela herbivoria prévia; os índices de consumo e utilização de alimento, de modo geral, foram mais elevados também para ‘Embrapa 4’ não injuriado. Nutritional aspects and larvae preference of Anticarsia gemmatalis Hüebner, 1818(Lepidoptera: Noctuidae) on damaged and undamaged soybean cultivarsAbstractResistance to insects can be due to chemical factors present in the plant, and, according to thenature of the compounds, the resistance may be constitutive (independent of environmentalstress), or induced by stress. In the case of soybeans, there are citations of constitutive and inducedresistance, and for induced resistance, the value of information produced by the plant depends, forexample, on the degree of the herbivore infestation. The induced resistance due to injury caused bythe feeding of caterpillars Pseudoplusia includens in soybean occurs and has its peak near the 10thday after the injury. This way, the objective of this paper was to study the influence of previous injuryin soybean genotypes, ‘Embrapa 4’ and ‘BR 37’, through the soybean defoliation by caterpillars,the preference and nutrition of Anticarsia gemmatalis. From the results obtained, it was possible toobserve that the genotype ‘Embrapa 4’ is preferred by the caterpillars of A. gemmatalis in relationto ‘BR 37’, with a much higher leaf area consumed. As for the first one, an evident induction ofresistance by a prior herbivory occurs, since the tests performed after defoliation show negativeinfluence on insect development; consumption and use of food indexes were, in general, higheralso for the variety ‘Embrapa 4’ which was not injured

Fecundity and pre-imaginal period of Chrysoperla externa (hagen) (neuroptera: chrysopidae) under different populations and laboratory generations

The lacewings appear in many agroecosystems, preying several species of agricultural pests. They have great search capability, high voracity, high reproductive potential and are easily maintained in laboratory conditions. In laboratory rearing, to avoid problems in the mass production are recommended adjustments in the type and quality of prey to be used in order to obtain individuals with desirable characteristics. It is necessary special care with the laboratory populations, avoiding problems from inbreeding. Larvae were reared individually in Petri dishes (9.0 cm diameter) and fed with eggs of Sitotroga cerealella (Olivier, 1789) (Lepidoptera: Gelechiidae), in the amount of 25 mg / larva, while the adults were kept in PVC cylindrical cages (10 cm x 30 cm). Thus, the study analyzed the influence of the size of the population of Chrysoperla externa (Hagen, 1861) (Neuroptera: Chrysopidae) on the pre-imaginal period (egg to adult) and reproductive capacity of this specie come from different populations and generations of laboratory. To this end, we used two populations, one of Jaboticabal (F-8 and F-21) and one of Piracicaba (F-6 and F-15), and subpopulations of 1, 5, 10, 15 and 20 couples, analyzing the incubation of eggs and the number of eggs per female in each population, generation and subpopulation. The pre-imaginal period (egg to adult) and the number of eggs per female of C. externa are influenced by the generation and the number of founding individuals, being these parameters favored when laboratory populations are established with the largest number of couples.Os crisopídeos aparecem em muitos agroecossistemas, predando várias espécies de organismos considerados pragas agrícolas, com elevada capacidade de busca, voracidade e elevado potencial reprodutivo. Em criação de laboratório, para se evitar problemas na produção são recomendadas adequações no tipo e na qualidade da presa a ser utilizada, visando obter indivíduos com características desejáveis, bem como cuidados especiais com as populações, evitando-se problemas oriundos da consanguinidade. As larvas foram criadas individualmente em placas de Petri (9,0 cm de diâmetro) e alimentadas com ovos de Sitotroga cerealella (Olivier, 1789) (Lepidoptera: Gelechiidae), na quantidade de 25 mg/larva, enquanto os adultos foram mantidos em gaiolas cilíndricas de PVC (10 cm x 30 cm). Assim, o trabalho analisou a influência do tamanho da população de Chrysoperla externa (Hagen, 1861) (Neuroptera: Chrysopidae) sobre o período pré-imaginal (ovo a adulto) e a capacidade reprodutiva desse predador oriundo de diferentes populações e gerações de laboratório. Foram utilizadas duas populações, uma de Jaboticabal (F8 e F21) e outra de Piracicaba (F6 e F15), e as subpopulações de 1, 5, 10, 15 e 20 casais, analisando-se a influência de populações e gerações de laboratório. O período pré-imaginal (ovo a adulto) e o número de ovos colocados por fêmea de C. externa são influenciados pela geração e pelo número de indivíduos fundadores, sendo esses parâmetros são favorecidos quando populações de laboratório são estabelecidas com maior número de casais

Subdosages of Bacillus thuringiensis on Plutella xylostella) (Lepepidoptera: plutellidae) and Trichogramma pretiosum (Hymenoptera: trichogrammatidae)

The aim of this paper was to evaluate the biological aspects of Plutella xylostella and Trichogramma pretiosum in eggs of the F2 generation of P. xylostella under the influence of Bacillus thuringiensis in laboratory conditions. The experiment was conducted in the Laboratorio de Biologia and Criacao de Insetos of Faculdade de Ciencias Agrarias e Veterinarias de Jaboticabal - UNESP reen collars contaminated with strains and commercial product based on B. thuringiensis in the laboratory. The eggs obtained from the F2 generation of P. xylostella evaluated the biological parameters of T. pretiosum. It was observed that some biological characteristics of P. xylostella showed changes by the treatment with B. thuringiensis. The viability of the larvae and pupae stages, pupae weight were the biological parameters more influenced by treatments, with values significantly reduced when compared to control. However, the larvae length and pupae stages and sex ratio were similar in all treatments, with no significant biological variations. Thus, this bacterium isolated from this behavior may provide greater exposure of larvae to other natural enemies as well as generation of adults less viable, which makes them potential programs in pest control, since the interaction of the methods of control is one of the main ways to enhance the biological control of insect pests. It was observed sublethal effects on P. xylostella biology, and B. thuringiensis negative influence on the parasitism capacity and emergency of T. pretiosum.O objetivo desta pesquisa foi avaliar aspectos biológicos de Plutella xylostella e de Trichogramma pretiosum em ovos de P. xylostella sob a influência de Bacillus thuringiensis em condições de laboratório. O experimento foi desenvolvido no Laboratório de Biologia e Criação de Insetos da Faculdade de Ciências Agrárias e Veterinárias de Jaboticabal – UNESP, utilizando-se delineamento inteiramente casualizado com 60 repetições. Para tanto, avaliou-se a biologia de P. xylostella em Brassica oleracea var. acephala (couve Manteiga) contaminada com isolados, linhagem e produto comercial a base de B. thuringiensis. A partir dos ovos obtidos da geração F2 de P. xylostella avaliaram-se os parâmetros biológicos de T. pretiosum. Observou-se que algumas características biológicas de P. xylostella apresentaram alterações mediante aos tratamentos com B. thuringiensis. A viabilidade larval e pupal, e o peso de pupas foram os parâmetros biológicos que mais sofreram influências dos tratamentos, com valores reduzidos significativamente em relação à testemunha. Já, as durações das fases de larva e de pupa, além da razão sexual, foram semelhantes em todos os tratamentos, não apresentando variações biológicas. Dessa forma, isolados desta bactéria com este comportamento podem proporcionar maior exposição das lagartas a outros inimigos naturais, bem como geração de adultos menos viáveis, o que os torna com potencial em programas de controle de pragas. Observou-se a existência de efeitos subletais na biologia de P. xylostella; e influência do B. thuringiensis na capacidade de parasitismo e de emergência de T. pretiosum