<b>Effect of anonaceous extracts on <i>Aphis gossypii</i> (Glover, 1887) (Hemiptera: Aphididae) and selectivity to <i>Eriopis connexa</i> (Germar, 1824) (Coleoptera: Coccinellidae)

Abstract

The effects of ethanolic and hexanic extracts of soursop and sugar apple (EES, EHS, EESA and EHSA, respectively) on Aphis gossypii (Hemiptera: Aphididae) and its natural enemy Eriopis connexa (Coleoptera: Coccinellidae) by contact exposure, residual effect and ingestion tests were evaluated. The estimated LC 50 and LC 99 values for A. gossypii were 0.39% and 5.47% for (EESA); 0.23% and 1.19% for (EES); 0.47% and 4.39% for (EHSA); and 0.42% and 6.38% for (EHS), respectively. Considering contact exposure, EES at 0.23% was innocuous, and EHS at 0.42% was slightly harmful; for adult ladybugs, only EESA (5.47%) was classified as slightly harmful, with the other treatments classified as harmless. The results were similar for the residual effect. For selectivity in ingestion tests, EES and EHS at the LC 50 did not affect the survival rate of the predator, but EESA (0.39% and 5.47% for the LC 50 and LC 99 , respectively) reduced the survival rate to zero in less than 7 days, resembling chemical treatment with Decis ®. Extracts applied to the eggs of an alternative prey reduced the consumption of eggs and therefore the predatory capacity of the ladybug, which led to a decrease in oviposition, egg viability and ultimately a reduction in predator fecundity. EES at a concentration of 0.23% was effective in the control of A. gossypii and was selective and did not affect the survival rate of the its natural enemy E. connexa.

The effects of Annonaceae and Amaryllidaceae extracts in controlling the Thrips tabaci Lindeman (Thysanoptera: Thripidae)

“…Among other families with promising plant extracts that are used as biopesticides are Amaryllidaceae, where garlic (Allium sativum L.) and long green onion (A. fistulosum L.) with various biological activities stand out, and their cytoxicities are of interest as options for the prevention and control of insect-pest infestation (Roldán et al, 2007;Denloye, 2010;Llana-Ruiz-Cabello et al, 2015) and Annonaceae, where the insecticide activity of different fruit species is highlighted, A. muricata L. being the most studied (Moghadamtousi et al, 2015;Dos Santos et al, 2018).…”