Insecticide potential of two saliva components of the predatory bug Podisus nigrispinus (Heteroptera: Pentatomidae) against Spodoptera frugiperda (Lepidoptera: Noctuidae) caterpillars

Abstract

The saliva of the predatory stink bug Podisus nigrispinus contains N,N-dimethylaniline (DMA) and 1,2,5-trithiepane, which kill prey. The mode of action of these components remains unknown and they were evaluated in Spodoptera frugiperda caterpillars. All compounds are toxic and cause damages in the midgut cells resulting in apoptosis and necrosis. The main features of these cells are apical protrusions with nucleus released to the lumen, vesicular rough endoplasmic reticulum, autolysosomes, and electron-dense lipid droplets. The tested biogenic compounds, P. nigrispinus saliva extract, DMA, and 1,2,5-trithiepane are toxic and have negative effects to S. frugiperda caterpillars.

Keywords:

• Cell death
• cytotoxicity
• extra-oral digestion
• histopathology
• insecticide
• predatory bug

Acknowledgements

The authors thank the Nucleus Center for Microscopy and Microanalysis of the “Universidade Federal de Viçosa” for the technical support.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

We thank the Brazilian institutions Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq), Coordenação de Aperfeiçoamento de Pessoal de Nível Superior-Brasil (CAPES) – Finance Code 001, Fundação de Amparo à Pesquisa do Estado de Minas Gerais (FAPEMIG) and Programa Cooperativo sobre Proteção Florestal/PROTEF do Instituto de Pesquisas e Estudos Florestais/IPEF for financial support.