EFFECTS OF CARBON-DIOXIDE ON THE MORTALITY OF LIPOSCELIS-BOSTRYCHOPHILA BAD AND LIPOSCELIS-ENTOMOPHILA (END) (PSOCOPTERA, LIPOSCELIDIDAE)

The reduction in adult emergence of Liposcelis entomophila eggs treate d with CO2 was observed to be a direct consequence of egg mortality. A dult emergence was inversely related to the CO2 concentration to which the eggs were exposed. The response of liposcelid eggs to hypercarbia (30-95% CO2) did not differ from the simple Ct relationship, Ct = k. Eggs of Liposcelis bostrychophila were noted to be > 2 times more tole rant to CO2 treatment than those of L. entomophila. Based on LT(50) an d LT(95) values for 1-to 3-wk-old females exposed to 45 and 60% CO2, L . bostrychophila was the more tolerant species. Increasing the CO2 con centration from 45 to 60% did not reduce the LT(95) in either species, At a fixed exposure period of 4 h, no corresponding increase in morta lity was observed in either species for CO2 concentrations > 45%. Simi lar responses were observed in L. bostrychophila for 3 and 5 h exposur es to various CO2 concentrations. The use of CO2-enriched atmospheres in the control of L. bostrychophila and L. entomophila is also discuss ed.