Effect of imidacloprid foliar treatment and banana leaf age on Pentalonia nigronervosa (Hemiptera, Aphididae) survival

Abstract

Pentalonia nigronervosa, the banana aphid, is the vector of Banana bunchy top virus to banana. This virus is the etiological agent of banana bunchy top disease, a limiting factor in many banana growing regions, including Hawaii, United States. Laboratory bioassays on banana plants were conducted to evaluate the efficacy of imidacloprid (Provado®), to control P. nigronervosa by comparing insect mortality at four different insecticide concentrations (120,60,24, and 12 ppm) over 1 month, and compared effects on the aphids on new emerging, and old leaf material. We found significant differences between treatments and time after treatment. Aphids survived poorly on newer plant growth, regardless of presence or absence of imidacloprid, or time after treatment. Examining the insecticidal effect on old leaves only, we found that the three highest concentration treatments resulted in high mortality over the 4‐week‐long period of testing. Our results confirm that imidacloprid foliar application on bananas results in effective control of aphids and does not become systemic within the plant. From these results, it is likely that management of banana aphid using imidacloprid under field conditions will be effective on old leaves and new leaves that are sprayed, but leaves emerging after sprays will not be completely protected from aphids. Regular scouting for aphids should be implemented in support of imidacloprid applications.