Toxicity of botanical insecticides on Diaphania hyalinata, their selectivity for the predatory ant Paratrechina sp., and their potential phytotoxicity on pumpkin

ABSTRACT

The use of botanical insecticides could be an alternative efficient pest management in Cucurbitaceae against melonworm Diaphania hyalinata and less harmful to its predator. Few studies jointly assess the efficiency of botanical insecticides, their effects on pest, and their effect on the natural enemy and target crop. Here we examine (1) their impact against the melonworm D. hyalinata, a key pest of Cucurbitaceae, (2) their toxicity to the predatory ant Paratrechina sp., and (3) their phytotoxicity to pumpkin plants. The botanical insecticides citronella oil and eucalyptus oil were highly toxic to D. hyalinata and they exhibited to be less harmful for the predatory ant Paratrechina sp. Andiroba oil, eucalyptus oil, garlic extract, and citronella oil caused feeding inhibition of the D. hyalinata larvae. Eucalyptus oil, andiroba oil, garlic extract, and rotenone inhibited the oviposition of D. hyalinata. None of the insecticides was phytotoxic to pumpkin plants. Eucalyptus oil and citronella oil have induced high mortality and altered the behavior of target pests. In addition, they were selective for the predator Paratrechina sp. and not exhibited phytotoxicity on pumpkin plants. Eucalyptus oil and citronella oil seem the most promising compounds for incorporation into melonworm management programs, because they induced high mortality and altered the behavior of target pests and were selective for the predator Paratrechina sp.

KEYWORDS:

• Eucalyptus oil
• citronella oil
• melonworm
• organic farming
• insecticide selectivity

Acknowledgments

The authors would like to thank the National Council for Scientific and Technological Development (Conselho Nacional de Desenvolvimento Científico e Tecnológico – CNPq), the Brazilian Federal Agency for the Support and Evaluation of Graduate Education (Coordenação de Aperfeiçoamento de Pessoal de Ensino Superior – CAPES), and the Research Support Foundation of the State of Minas Gerais (Fundação de Amparo à Pesquisa do Estado de Minas Gerais – FAPEMIG) for the financial support they extended toward this research.

Disclosure statement

The authors declare that they have no conflict of interest.

Additional information

Funding

The Research Support Foundation of the State of Minas Gerais (Fundação de Amparo à Pesquisa do Estado de Minas Gerais – FAPEMIG). National Council for Scientific and Technological Development (Conselho Nacional de Desenvolvimento Científico e Tecnológico – CNPq), the Brazilian Federal Agency for the Support and Evaluation of Graduate Education (Coordenação de Aperfeiçoamento de Pessoal de Ensino Superior -- CAPES).