Field Selection for Endosulfan Resistance in Coffee Berry Borer (Coleoptera: Scolytidae) in New Caledonia

Publisher Website
Google Scholar
Abstract
A direct spray technique was used to monitor the frequency of endosulfanresistant Hypothenemus hampei (Ferrari) in transects across individual coffee fields that had been sprayed from the road. A rapid decrease in resistance frequency (phenotypic cline) away from the road was evident in one traditional low-density (shady) and two modern intensive (sunny) fields surveyed in 1988. Subsequent treatment of one sunny field with two applications of endosulfan in 1989 resulted in an increase in the frequency of the endosulfan-resistant phenotype by an average of 61.4% across the field. In contrast, treatment of a second sunny field with fenitrothion led to decreased frequency of the endosulfan-resistant phenotype by an average of 12% across the field. Concentration-mortality responses for beetles from particular locations in the fields (e.g., the roadside or most distant side) confirmed results obtained with the diagnostic concentration (LC99.95 of susceptible individuals). After 1 year, frequency of the phenotype resistant to endosulfan also declined an average of 18% in a shady field treated with fenitrothion. Responses of beetles collected from the roadsides of other coffee fields confirmed that the frequency of the resistant phenotype declined an average of 47.3% at sunny fields and 34.5% at shady fields in the second year, after fenitrothion began to be used. Further applications of endosulfan raised the resistance frequency in four of five fields in the second year. Changes in frequency of the resistance phenotype in the absence of the insecticide suggest that the frequency of endosulfan resistance may not decline rapidly enough to justify reintroduction of endosulfan within several years.

This publication has 0 references indexed in Scilit: