MORTALITY OF BLACK FIELD CRICKETS (TELEOGRYLLUS-COMMODUS) IN CARBON-DIOXIDE ATMOSPHERES

The efficacy of controlled atmospheres (CA) incorporating 5, 9, 18, 30 , and 57% CO2 with 20% O-2, balance N-2 or 57% CO2 with 12% O-2, balan ce N-2 were tested for the postharvest disinfestation of horticultural crops using black field crickets (Teleogryllus commodus Walker) as a model insect. Crickets were also exposed to air as a control. Exposure times ranged from 2 to 48 h at 20 degrees C. Crickets were then left for 24 h in air, and mortality was assessed. Exposure time and CA sign ificantly affected insect mortality. There was very low mortal ity (<3 .5%) in air, in 5% and in 9% CO2 with 20% O-2. Mortality generally inc reased with increasing exposure time in CA with greater than or equal to 18% CO2. The estimated exposure time required to achieve 99% cricke t mortality (LT(99)) was 62.8 h for 18% CO2, 20% O-2, and 31.7 h for 5 7% CO2, 20% O-2. The longer LT(99) for 57% CO2, 12% O-2 of 42.4 h indi cates that a combination of high CO2 (57%) and 20% O-2 could be an eff ective CA for postharvest insect disinfestation.