Seletividade dos extratos etanólicos de Annona muricata L. e Annona squamosa L. (annonaceae) sobre o predador Cryptolaemus montrouzieri Mulsant, 1853 (coleoptera: coccinellidae)

Abstract

The biological control of insects acts in a balanced way with the environment and shows quite efficient when combined with other control methods. Selectivity studies of botanical insecticides over natural enemies are essential for association or biological control with alternative control within Integrated Pest Management (MIP). Among the biological control agents, the group of predators deserves to be highlighted the species of the Coccinellidae family, as they are known for their voracity and for their generalist eating habits. The objective of this work was to evaluate the selectivity of the extracts of Annona muricata L. and Annona squamosa L. over the predator Cryptolaemus montrouzieri Mulsant, 1853 (Coleoptera: Coccinellidae). The choices of the concentrations used were based on studies of the acid action of the ethanolic extracts of A. muricata and A. squamosa by Santos et al. (2018), ethanol extract of soursop (EEG 0.23 and 1.19%) and ethanol extract of pine cone (EEP 0.39 and 5.47%), the product formulated with acetogenin Anosom® and the commercial product Decis 25 EC® both tested at the dose recommended by the manufacturer, plus a witness. The tested products were classified according to the selectivity standards of the International Working Group with Beneficial Organisms and Pesticides of the International Organization of Biological Control (IOBC). In the action of contact extracts, EEG 0.23 and 1.19%, and EEP 0.39% were considered innocuous to the larvae of the fourth instar and to the adults of the predator, different from the treatment with Decis 25 EC® (positive control treatment) that was harmful to the predator. For the residual effect, all treatments, except Decis 25 EC®, were harmless to larvae and adults of C. montrouzieri. Regarding the selectivity of extracts by ingestion, EEG 0.23 and 1.19% and EEP 0.39% were classified as innocuous the larvae and adults of the predator, similar to the treatment with Anosom®, different from EEP 5, 47% that caused mortality in 30% of fourth instar larvae and 40% of treated adults, being classified as moderately harmful. The number of eggs of the couples who ingested the pine cone and soursop extracts did not differ statistically from the control and the viability of these eggs also showed no significant difference. EEG was the only treatment classified as innocuous for the two phases of development evaluated, in the three bioassays performed, presenting itself as an alternative control form compatible with the biological control agent of C. montrouzieri.