The tolerance of tomato potato psyllid life stages to ethyl formate

Abstract

Methyl bromide fumigation became mandatory for capsicums and truss tomatoes exported to Australia after tomato potato psyllid (TPP) was detected in 2006 in New Zealand. Methyl bromide detrimentally affects product quality by increasing rots and the browning of the green stems. An alternative being tested is ethyl formate (EF) and carbon dioxide, commercially available as VAPORMATE®. This study examined the tolerances of different life stages of TPP to EF. Eggs were considerably more tolerant of EF than adults and nymphs. Complete elimination of egg hatch was achieved after a 1-h exposure to 1.19% EF. In contrast, all nymphs and adults were killed after a 1-h exposure to 0.12% and 0.06% EF, respectively. Assessment of egg mortality was altered to better reflect the post-hatch treatment effects on nymph survival. In a subsequent egg age tolerance trial, mean lethal concentrations for 99% mortality ranged from ca 1% EF for young and older eggs to ca 1.5% EF for mid-aged eggs.