Postharvest management of New Zealand flower thrips (Thrips obscuratus) on apricots using ethyl formate or pyrethrum-based treatments

Abstract

New Zealand lower thrips (NZFT, Thrips obscuratus (Crawford)) were exposed to a range of ethyl formate (EF) and pyrethrum-based postharvest treatments on apricots. Research showed that EF+CO2 or EF+N2 were effective treatments against NZFT and caused negligible damage to apricot fruit quality. However, pyrethrum dipping did not effectively control NZFT and caused signiicant internal damage to apricot fruit. Lethal concentration (LC99) estimates were developed for adult and larval NZFT using a range of EF concentrations (0-1.27% EF+CO2) and temperatures (5, 15 and 25°C). It is estimated that treatments of 1% (30.7 g/m3) EF at 5 or 25°C or a higher concentration of 1.5% (46.3 g/m3) at 15°C will achieve 99% mortality of NZFT adults and larvae on apricot fruit with 95% conidence. © 2013 New Zealand Plant Protection Society.