Efeitos de óleos essenciais sobre abelhas nativas Nannotrigona testaceicornis e Trigona spinipes (Hymenoptera: apidae) e o percevejo predador Podisus nigrispinus (Heteroptera:pentatomidae)

Abstract

The usage of botanical insecticides in biological control of pests in agricultural and forest crops has emerged as a potential less harmful alternative to the environment. The usage of botanical extracts and essential oils for pests control has promising results in plant plant mortality under laboratory and field conditions. However, just like synthetic insecticides, botanical ones can also cause damage to insects, such as pollinators and natural enemies, compromising biodiversity and the productivity in agroecosystems. Thus, this project aims to evaluate the toxicity of both botanical and synthetic insecticides on brazilian native bees Nannotrigona testaceicornis and Trigona spinipes, and the insect-predator P. nigrispinus. The ways of exposure were by topical application and ingestion. Mortality values were corrected through the Abbot formula. The lethal doses (LD50 and LD90) and lethal concentrations (LC50 and LC90) were further obtained through probit analysis at 95%. For the Lethal Time (LT50) bioassays, the previous concentrations obtained were used in order tostablish the Lethal Time for 50% the insects population. Botanical insecticides were less toxic to native bees N. testaceicornis and Trigona spinipes compared to the synthetic insecticide Deltametrina. The botanical insecticides were also less toxic to P. nigrispinus nymphs when compared to Deltametrina. However, an influence on the morphology of the insects was observed, interrupting theirdevelopment to the adult stage, showing sub-lethal effect.