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

Abstract

A principal praga-alvo na cultura do milho é a lagarta-do-cartucho, Spodoptera frugiperda (J.E. Smith, 1797) (Lepidoptera: Noctuidae), que, pela sua ampla distribuição temporal e geográfica constitui-se em uma das espécies mais nocivas nas regiões tropicais das Américas. O objetivo foi avaliar o estádio de adaptação de S. frugiperda em 17 espécies hospedeiras, cultivadas ou selvagens, mais comuns no agroecossistema brasileiro. As plantas foram cultivadas em cinco épocas, entre 2006 e 2008, utilizando o milho como padrão. Larvas de S. frugiperda recém-eclodidas foram individualizadas e confinadas em copo plás-tico (50 mL), onde foram alimentadas com seções de folha nova de cada hospedeiro. O alimento foi substituído a cada dois dias por folhas frescas. Quatro variáveis biológicas foram avaliadas e utilizadas para se calcular um Índice de Adaptação (IA). Os resultados indicaram que a sobrevivência inicial de S. frugiperda variou de 100%, no milho, a 46%, no arroz. O período 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 índice de adaptação, calculado com base nas variáveis biológicas de S. frugiperda, nos hospedeiros avaliados, variou de 17,43, no milho cultivado na época I, a 1,46, na cana-de-açúcar na época III. Para corrigir o efeito de época sobre o índice de adaptação de S. frugiperda nos hospedeiros, foi calculado o Índice Relativo de Adaptação (IRA), com base no índice de adaptação no milho (100%). Assim, com base no índice relativo de adaptação, estimado em condições de laboratório, os hospedeiros alternativos ao milho, para S. frugiperda, podem ser assim ordenados, do maior para o menor índice: sorgo granífero, sorgo selvagem, milheto, capim-tanzânia, amendoim, capim-marandu, capim-braquiária, caruru-de-porco, trigo, soja, algodão, feijão, arroz, capim-carrapicho, grama batatais e cana-de-açúcar.Palavras-chave: ecologia, interação inseto-planta, manejo de pragas, lagarta-do-cartucho.Fitness stage of Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae) on alternative hosts AbstractThe main target pest on maize is the fall armyworm, Spodoptera frugiperda (J.E. Smith, 1797) (Lepidoptera: Noctuidae), which, by their seasonal and geographical distribution is one of the most damaging species in tropical regions of America. The objective was the evaluation of S. frugiperda fitness stage on 17 host plant species, cultivated or wild, most common in the Brazilian agro ecosystem. The plants were cultivated in five planting times, between 2006 and 2008, using corn as standard of comparison. Newly hatched larvae of S. frugiperda were individualized and confined in 50 mL plastic pots, where they were fed with new leaves of each host. Food was replaced every other day with fresh leaf sections of each plant host. Four biological variables were evaluated and used to estimate the Fitness Index (FI). The initial larval survival ranged from 100% on maize to 46% on rice. The larval period ranged from 12.6 days on maize...

Developmental Parameters of Spodoptera frugiperda (Lepidoptera: Noctuidae) Immature Stages Under Controlled and Standardized Conditions

“…The larval survival (Table 1) was high when compared to other reports for S. frugiperda fed on artificial diet (Pencoe & Martin, 1982;Lynch, Nwanze, Wiseman, & Perkins, 1989;Clavijo et al, 1991;Giolo, Grutzmacher, Garcia, & Busato, 2002) and some of its main hosts (Pencoe & Martin, 1982;Ali, Luttrell, & Pitre, 1990). In addition, larval survival was higher than that reported in the majority of studies with this species, both on artificial and natural diet when larvae are exposed to less favorable temperatures and unsuitable host plants (e.g., Piedra, 1974;Kasten, Precetti, & Parra, 1978;Garner & Lynch, 1981;Pitre & Hogg, 1983;Parra & Carvalho, 1984;Crocomo & Parra, 1985;Ali et al, 1990;Silveira, Vendramim, & Rossetto, 1997;Botton, Carbonari, Garci, & Martins, 1998;Murúa, Defagó, & Virla 2003;Busato et al, 2005;Boregas, Mendes, Waquil, & Fernandes, 2013;Dias et al, 2016;Silva et al, 2017).…”

Efficiency of biological control for fall armyworm resistant to the protein Cry1F

“…Therefore, the use of integrated pest management (IPM), which optimizes the use of different management methods and strategies, has been increasingly recommended in the search for greater sustainability in cultivation systems (Van Lenteren et al, 2018). One of the most widespread pests in tropical cultivation systems and of great importance in the Americas is the fall armyworm Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae) (Boregas et al, 2013;Goergen et al, 2016). The fall armyworm is considered the principal pest for corn, reducing the production of grains by up to 34% (Cruz, 1995;Figueiredo et al, 2006).…”

Selection and characterization of Bacillus thuringiensis isolates with a high insecticidal activity against Spodoptera frugiperda (Lepidoptera: Noctuidae)

“…The main trouble with the control of this pest is due to this insect behavior, which remains within the plant cartridges, reducing the contact with insecticides applied for its control (BRAGA MAIA et al, 2013). Moreover, in the conventional agricultural systems, the effects caused by changes in biodiversity and instability between trophic levels make the control of S. frugiperda increasingly difficult and costly (SANTOS-AMAYA et al, 2016;BOREGAS et al, 2013). The chemical control of insects in agriculture has been estimated to cost US$ 1391 miillion dollars annually in the united states (PIMENTEL, 2005), thus sustainable insect pest control is of vital importance.…”