Infestation of European corn borer (Lepidoptera: Crambidae) in sweet corn as predicted by time of oviposition.

Oviposition by European corn borer, Ostrinia nubilalis Hübn, was examined in relation to sweet corn development from 1994 to 1996, and related to harvest infestation levels. Stepwise multiple regression and linear regression showed that 79-87% of the variability of larvae per ear or proportion of ears infested at harvest was explained by the number of egg masses laid from about anthesis to brown silk stages. The analyses indicated three periods of oviposition with differing implications to harvest infestation level: (1) eggs laid from 784-337 degree-days (DD) before harvest (before green tassel) had very low correlation to harvest infestation; (2) eggs laid from 336-169 DD before harvest (green tassel to green silk) were highly correlated with harvest infestation; and (3) eggs laid during the last 168 DD of sweet corn development (green silk to harvest) had low to moderate correlation with harvest infestation.

Effect of high-carbon dioxide atmospheres on infestations of apple maggot (Diptera: Tephritidae) in apples.

Short-term storage regimens containing elevated atmospheres of carbon dioxide (CO2) were evaluated for their ability to disinfest newly harvested 'McIntosh' apples of apple maggot, Rhagoletis pomonella (Walsh). Infested fruits containing newly laid eggs were either placed directly into the high-CO2 atmosphere at 10 degrees C to expose this life stage, or else held first for 7 d at room temperature, to allow development to the neonate larval stage. Treatment combinations consisted of three different CO2 levels (10.