EFFECT OF CARBON DIOXIDE CONCENTRATION IN AIR ON SOME BIOLOGICAL ASPECTS OF THE ONION BULB FLY, Eumerus vestitus BEZZI (SYRPHIDAE, DIPTERA)

Document Type : Original Article

Author

Department of Economic Entomology and Pesticides, Faculty of Agriculture, Cairo University, Giza, Egypt.

Abstract

The 2nd, 3'd instar larvae, 3 and 8 days old pupae of the onion bulb fly, E.
v
estitus were exposed to 3 different concentrations of CO2 in air for 24, 48 and 72 hr.
The rate of mortality in all treatments was positively correlated with C02-concentration
air and the exposure period . Treatments of the 2nd and 3'd instar larvae resulted
increasing the larval duration while the rate of pupation was reduced by increasing the
C02 concentration and/or the exposure period. Also, the pupal duration was increased
while the rate of adult emergence was greatly reduced.
Treatments of 3 and 8 days old pupae resulted increasinq the pupal
duration but the percent of adult emergence was decreased by increasing the C02
concentration and/or the exposure period. In general, the pupae were more tolerant
than the larvae and the 8 days old pupae were more sensitive than the 3 days pupae.