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The perception of herbivory by plants is known to be triggered by the deposition of insect-derived factors such as saliva and oral secretions, oviposition materials, and even feces. Such insect-derived materials harbor chemical cues that may elicit herbivore and/or pathogen-induced defenses in plants. Several insect-derived molecules that trigger herbivore-induced defenses in plants are known; however, insect-derived molecules suppressing them are largely unknown. In this study, we identified two plant chitinases from fall armyworm (Spodoptera frugiperda) larval frass that suppress herbivore defenses while simultaneously inducing pathogen defenses in maize (Zea mays). Fall armyworm larvae feed in enclosed whorls of maize plants, where frass accumulates over extended periods of time in close proximity to damaged leaf tissue. Our study shows that maize chitinases, Pr4 and Endochitinase A, are induced during herbivory and subsequently deposited on the host with the feces. These plant chitinases mediate the suppression of herbivore-induced defenses, thereby increasing the performance of the insect on the host. Pr4 and Endochitinase A also trigger the antagonistic pathogen defense pathway in maize and suppress fungal pathogen growth on maize leaves. Frass-induced suppression of herbivore defenses by deposition of the plant-derived chitinases Pr4 and Endochitinase A is a unique way an insect can co-opt the plant's defense proteins for its own benefit. It is also a phenomenon unlike the induction of herbivore defenses by insect oral secretions in most host-herbivore systems.

Neotropical Entomology 37(1): 030-044 (2008) Revisão de Neomegalotomus (Hemiptera: Alydidae) RESUMO -Duas espécies de Neomegalotomus, N. parvus (Westwood), a espécie tipo, e N. rufi pes (Westwood) são reconhecidas. As duas espécies são redescritas a partir de espécies tipo e a chave para identifi cação é apresentada. As seguintes espécies são sinonimizadas com Neomegalotomus parvus: N. simplex (Westwood), N. latifascia (Berg), e N. pallescens (Stål) (todas novas sinonímias). N. jamaicensis (Westwood) é sinonimizada com N. rufi pes (nova sinonímia). As espécies tipo de todas as espécies até agora colocadas no gênero são também redescritas, exceto N. debilis (Walker) e N. vicinus (Westwood). N. parvus ocorre do México através da América Central até o norte da Argentina e em direção à Venezuela e ilhas caribenhas adjacentes ao leste. N. rufi pes encontra-se espalhada no sul do Caribe em direção à Venezuela. As duas espécies se sobrepõem em distribuição: N. parvus é encontrado em St. Vincent e Tobago, enquanto N. rufi pes ocorre em Grenada, a qual situa-se entre essas duas ilhas. PALAVRAS-CHAVE: Heteroptera, praga-da-soja, neotrópicos, Caribe ABSTRACT -We recognize two species in Neomegalotomus, N. parvus (Westwood), the type species; and N. rufi pes (Westwood). The two species are redescribed from type specimens, and are keyed. We synonymize the following species with Neomegalotomus parvus: N. simplex (Westwood), N. latifascia (Berg), and N. pallescens (Stål) (all new synonymies). We synonymize N. jamaicensis (Westwood) with N. rufi pes (new synonymy). The type specimens of all species hitherto placed in the genus are also redescribed, except those of N. debilis (Walker) and N. vicinus (Westwood). N. parvus occurs from México through Central America into northern Argentina and east into Venezuela and adjacent Caribbean islands. N. rufi pes is widespread in the Caribbean south towards Venezuela. The two species overlap in distribution: N. parvus is found on St. Vincent and Tobago, whereas N. rufi pes occurs on Grenada, which lies between those two islands.

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