The fall armyworm, Spodoptera frugiperda (J.E. Smith, 1797) (Lepidoptera: Noctuidae), is the most important noctuid pest in the Americas and has recently become an invasive pest in Africa. A detailed record of S. frugiperda's host plants is essential to better understand the biology and ecology of this pest, conduct future studies, and develop Integrated Pest Management programmes. In this study, we collected and systematically arranged the fragmented bibliographic information on S. frugiperda feeding records. Furthermore, we registered new records of host plants for S. frugiperda based on eight years of surveys in Brazil. The literature review and surveys resulted in a total of 353 S. frugiperda larval host plant records belonging to 76 plant families, principally Poaceae (106), Asteraceae (31) and Fabaceae (31). The literature search revealed 274 (77 % of total) bibliographic records, while 82 (23 %) are new records from surveys in Brazil. The new comprehensive and updated host plant list will improve our understanding of pest biology and management, as well as facilitate future studies on this pest.

/pdf/host-plants-of-spodoptera-frugiperda-lepidoptera-noctuidae-24uej9ywjw.pdf

Host Plants of Spodoptera frugiperda (Lepidoptera: Noctuidae) in the Americas

Bioactivities of cymol and essential oils of Cupressus sempervirens and Eucalyptus saligna against Sitophilus zeamais Motschulsky and Tribolium confusum du Val

A comparative study was conducted to assess the contact and fumigant toxicities of eleven monoterpenes on two important stored products insects—, Sitophilus oryzae, the rice weevil, and Tribolium castaneum, the rust red flour beetle. The monoterpenes included: camphene, (+)-camphor, (−)-carvone, 1-8-cineole, cuminaldehyde, (l)-fenchone, geraniol, (−)-limonene, (−)-linalool, (−)-menthol, and myrcene. The inhibitory effect of these compounds on acetylcholinesterase (AChE) activity also was examined to explore their possible mode(s) of toxic action. Although most of the compounds were toxic to S. oryzae and T. castaneum, their toxicity varied with insect species and with the bioassay test. In contact toxicity assays, (−)-carvone, geraniol, and cuminaldehyde showed the highest toxicity against S. oryzae with LC50 values of 28.17, 28.76, and 42.08 μg/cm2, respectively. (−)-Carvone (LC50 = 19.80 μg/cm2) was the most effective compound against T. castaneum, followed by cuminaldehyde (LC50 = 32.59 μg/cm2). In contrast, camphene, (+)-camphor, 1-8-cineole, and myrcene had weak activity against both insects (i.e., LC50 values above 500 μg/cm2). In fumigant toxicity assays, 1-8-cineole was the most effective against S. oryzae and T. castaneum (LC50 = 14.19 and 17.16 mg/l, respectively). Structure-toxicity investigations revealed that (−)-carvone—, a ketone—, had the highest contact toxicity against the both insects. 1-8-Cineole—, an ether—, was the most potent fumigant against both insects. In vitro inhibition studies of AChE from adults of S. oryzae showed that cuminaldehyde most effectively inhibited enzyme activity at the two tested concentrations (0.01 and 0.05 M) followed by 1-8-cineole, (−)-limonene, and (l)-fenchone. 1-8-Cineole was the most potent inhibitor of AChE activity from T. castaneum larvae followed by (−)-carvone and (−)-limonene. The results of the present study indicate that (−)-carvone, 1,8-cineole, cuminaldehyde, (l)-fenchone, and (−)-limonene could be effective biocontrol agents against S. oryzae and T. castaneum.

Fumigant and Contact Toxicities of Monoterpenes to Sitophilus oryzae (L.) and Tribolium castaneum (Herbst) and their Inhibitory Effects on Acetylcholinesterase Activity

https://bib.irb.hr/datoteka/330786.Rozman-article.pdf

Toxicity of naturally occurring compounds of Lamiaceae and Lauraceae to three stored-product insects

This review describes the major stored-product insect species and their resistance to insecticides. The economic importance of the control of those pests is highlighted with a loss of more than one billion US dollars per year worldwide. A detailed common description of species resistance throughout the world has been developed, and we observed 28 recurrent studied species involved in resistance cases disseminated on the five continents. The different mechanisms, including behavioral resistance, were studied particularly on Oryzaephilus surinamensis. The role of detoxifying enzymes and studies on the genetic resistance, involving the kdr mutation mechanisms and the transmission of the genes of resistance, are also described. A chapter clarifying definitions on cross and multiple resistance is enclosed.

A review of control methods and resistance mechanisms in stored-product insects.

Insecticidal activity of monoterpenes against Rhyzopertha dominica (F.) and Tribolium castaneum (Herbst)

No Brasil, a utilizacao de milho transgenico (Bt) pode reduzir perdas causadas por varios lepidopteros-pragas, equivalentes a aproximadamente 500 milhoes de dolares anuais. O objetivo deste trabalho foi avaliar os hibridos de milho Bt disponiveis no mercado americano para resistencia a lagarta-do-cartucho do milho (LCM), Spodoptera frugiperda (Smith) (Lepidoptera: Noctuidae). Nove hibridos de milho Bt expressando as toxinas Cry 1F, Cry 1A(b), Cry 1 A(c) e Cry 9C, alem de um hibrido (MP 704 X 707) expressando resistencia natural para a LCM, foram comparados num experimento, em campo, em blocos ao acaso, com parcela subdividida e quatro repeticoes. Nas parcelas, foram comparados os dez hibridos e, nas subparcelas, as versoes Bt versus nao-Bt, ou hibrido com resistencia natural versus susceptivel. A infestacao artificial foi realizada 33 dias apos a semeadura e as avaliacoes basearam-se no numero de larvas sobreviventes, aos 10 e 15 dias apos a infestacao, peso das larvas sobreviventes e notas de danos nas plantas. Para todas as variaveis estudadas, os resultados demonstraram diferencas significativas (P=0,05) entre os hibridos avaliados. Tambem as testemunhas nao-Bts diferiram significativamente dos respectivos hibridos Bts, exceto para aqueles expressando a toxina Cry 9C. O hibrido 2722 IMI, expressando a toxina Cry 1F, foi o mais resistente (imune) e os hibridos expressando a toxina Cry 1A(b) e a resistencia natural foram moderadamente resistentes. Em geral, os hibridos transgenicos resistentes produziram cerca de 32% a mais de graos que as testemunhas suscetiveis.

/pdf/resistencia-do-milho-zea-mays-l-transgenico-bt-a-lagarta-do-gz0awf5lsv.pdf

RESISTÊNCIA DO MILHO (Zea mays L.) TRANSGÊNICO (Bt) À LAGARTA-DO-CARTUCHO, Spodoptera frugiperda (Smith) (LEPIDOPTERA: NOCTUIDAE)

The fall armyworm (Spodoptera frugiperda (J. E. Smith)) has been controlled with synthetic insecticides bringing risk to the environment. Neem (Azadirachta indica A. Juss) is reported to be a natural alternative to synthetic insecticides against many insect species. The objective of this work was to evaluate the activity of neem leaves aqueous extract on fall armyworm, in laboratory. Bioassays carried out using artificial feed with various extract concentrations, and chlorpyrifos as control, indicated, 15 days after larvae infestation, similar efficiency in concentrations from 3.60 to 10.00 mg mL-1. Probit analysis showed LC50 = 2.67 mg mL -1. Hence, aqueous extract from neem leaves are active against fall armyworm.

/pdf/atividade-de-extrato-aquoso-de-folhas-de-nim-azadirachta-2ptyc92rpy.pdf

Atividade de extrato aquoso de folhas de nim (Azadirachta indica) sobre Spodoptera frugiperda

O objetivo deste trabalho foi avaliar parâmetros biologicos da lagarta-do-cartucho do milho (Spodoptera frugiperda), alimentada com hibridos de milho Bt, que expressam a toxina Cry 1A(b), e com seus respectivos isogenicos nao Bt. Os experimentos foram realizados no laboratorio da Embrapa Milho e Sorgo, em Sete Lagoas, MG. Os parâmetros avaliados foram: sobrevivencia de larvas apos 48 horas, sobrevivencia da fase larval e pre-imaginal, biomassa de larvas aos 14 dias de idade, biomassa de pupas, periodo de desenvolvimento larval, e nao preferencia alimentar de larvas do primeiro instar. Larvas de S. frugiperda apresentam menor sobrevivencia nas primeiras 48 horas de alimentacao e durante toda a fase larval, na maioria dos hibridos de milho Bt, em comparacao ao milho nao Bt. A biomassa de larvas e pupas foi sempre menor no milho Bt, e o periodo larval e o pre-imaginal, maior. Houve interacao entre a toxina Cry 1A(b) e a base genetica dos hibridos transgenicos, quanto a sobrevivencia e a biomassa larval. Larvas recem-eclodidas de S. frugiperda apresentam preferencia pela alimentacao em milho nao Bt.

/pdf/respostas-da-lagarta-do-cartucho-a-milho-geneticamente-4d220pznu7.pdf

Respostas da lagarta‑do‑cartucho a milho geneticamente modificado expressando a toxina Cry 1A(b)

A principal praga-alvo na cultura do milho e a lagarta-do-cartucho, Spodoptera frugiperda (J.E. Smith, 1797) (Lepidoptera: Noctuidae), que, pela sua ampla distribuicao temporal e geografica constitui-se em uma das especies mais nocivas nas regioes tropicais das Americas. O objetivo foi avaliar o estadio de adaptacao de S. frugiperda em 17 especies hospedeiras, cultivadas ou selvagens, mais comuns no agroecossistema brasileiro. As plantas foram cultivadas em cinco epocas, entre 2006 e 2008, utilizando o milho como padrao. Larvas de S. frugiperda recem-eclodidas foram individualizadas e confinadas em copo plastico (50 mL), onde foram alimentadas com secoes de folha nova de cada hospedeiro. O alimento foi substituido a cada dois dias por folhas frescas. Quatro variaveis biologicas foram avaliadas e utilizadas para se calcular um Indice de Adaptacao (IA). Os resultados indicaram que a sobrevivencia inicial de S. frugiperda variou de 100%, no milho, a 46%, no arroz. O periodo larval variou de 12,6 dias, no milho, a 27,1 dias, na grama batatais. A biomassa de pupa variou de 173,1 mg, no carrapicho, a 294,2 mg, no milho. O indice de adaptacao, calculado com base nas variaveis biologicas de S. frugiperda, nos hospedeiros avaliados, variou de 17,43, no milho cultivado na epoca I, a 1,46, na cana-de-acucar na epoca III. Para corrigir o efeito de epoca sobre o indice de adaptacao de S. frugiperda nos hospedeiros, foi calculado o Indice Relativo de Adaptacao (IRA), com base no indice de adaptacao no milho (100%). Assim, com base no indice relativo de adaptacao, estimado em condicoes de laboratorio, os hospedeiros alternativos ao milho, para S. frugiperda, podem ser assim ordenados, do maior para o menor indice: sorgo granifero, sorgo selvagem, milheto, capim-tanzânia, amendoim, capim-marandu, capim-braquiaria, caruru-de-porco, trigo, soja, algodao, feijao, arroz, capim-carrapicho, grama batatais e cana-de-acucar.

/pdf/estadio-de-adaptacao-de-spodoptera-frugiperda-j-e-smith-2xe4ntgx5n.pdf

José M. Waquil

Papers

Insecticidal activity of monoterpenes against Rhyzopertha dominica (F.) and Tribolium castaneum (Herbst)

RESISTÊNCIA DO MILHO (Zea mays L.) TRANSGÊNICO (Bt) À LAGARTA-DO-CARTUCHO, Spodoptera frugiperda (Smith) (LEPIDOPTERA: NOCTUIDAE)

Atividade de extrato aquoso de folhas de nim (Azadirachta indica) sobre Spodoptera frugiperda

Respostas da lagarta‑do‑cartucho a milho geneticamente modificado expressando a toxina Cry 1A(b)

Estádio de adaptação de Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae) em hospedeiros alternativos