Toxicity of Jatropha and Neem Oil Combination on Pink Hibiscus Mealybug

Abstract

Maconellicoccus hirsutus (pink hibiscus mealybug) is a polyphagous pest species reported in about 350 species of host plants worldwide. The chemical control method is still the most used for the control of agricultural pests. In view of this, we aim to evaluate the potential of the concentration of oils extracted from the species Azadirachta indica (Neem) and Jatropha curcas (Jatropha) on M. hirsutus, aiming at a management alternative for the pest. The experiments were carried out in air-conditioned chambers at a temperature of 25 ± 1ºC, relative humidity of 70 ± 10% and a photophase of 12h. The concentration 3% (v v-1) (defined in preliminary dilution tests) was used in the tests, with 11 interaction ratios between the oils. Mortality was assessed daily up to 72 hours after spraying. The application was carried out in two ways: indirect - on the food and walking surface; and direct - about insects. The indirect application caused higher levels of mortality in relation to the direct application. However, there was no significant difference between the concentrations for the indirect application. In the form of direct application, the combination of 60:40% neem oil and jatropha oil was the treatment that provided the highest mortality of the M. hirsutus (86.21%). The combinations between neem and jatropha oils demonstrated the potential to control M. hirsutus in both routes of application, being an alternative for the management of this pest.