Toxicity of new pyrethroid in pest insects Asciamonuste and Diaphania hyalinata, predator Solenopsis saevissima and stingless bee Tetragonisca angustula

ABSTRACT

There is increasing demand for new products for vegetable pest management. Thus, the aim of this study was to assess the toxicity of pyrethroids with acid moiety modifications to measure the insecticidal activity of these compounds on the lepidopteran vegetable pests Diaphania hyalinata (L.) (Lepidoptera: Pyralidae) and Asciamonuste (Latreille) (Lepidoptera: Pieridae) and evaluate their selectivity for the predatory ant Solenopsis saevissima (F. Smith) (Hymenoptera: Formicidae) and pollinator Tetragonisca angustula (Latreille) (Hymenoptera: Apidae: Meliponinae). Racemic mixtures of five new pyrethroids (30 µg molecule mg⁻¹ insect body weight) resulted in high (100%) and rapid (stable LD₅₀ after 12 h) mortality in D. hyalinata and A. monuste. In A. monuste, the trans-pyrethroid [12] isomer showed similar toxicity to permethrin. For D. hyalinata, the trans-pyrethroid [9] isomer and cis-pyrethroid [10] isomer were as toxic as permethrin. Due to their low selectivity, these new pyrethroids should be applied on the basis of ecological selectivity principles to minimize impacts on nontarget organisms S. saevissima and T. angustula.

KEYWORDS:

• Chemical control
• new molecules
• selectivity
• nontarget organisms
• insecticide synthesis
• Cucurbitaceae
• Brassicaceae

Funding

We are grateful for the financial support provided by the National Council of Scientific and Technological Development (CNPq), CAPES Foundation (Brazilian Ministry of Education) and the Minas Gerais State Foundation for Research Aid (FAPEMIG).