Fumigation of the Confused Flour Beetle with Methyl Bromide at High and Low Rates of Respiration

Abstract

Adults of the confused flour beetle, Tribolium confusum Jacquelin duVal, were exposed to a sublethal concentration (2.9 mg per liter) of methyl bromide at low and high rates of respiration induced by CO2 or N2 preconditioning. Susceptibility to methyl bromide was noted at the low respiratory level. Fumigation of CO2-and N2-preconditioned beetles at respiratory depression produced 30% and 44% greater joint action, respectively, than that which could be predicted on the basis of additive treatments. These results suggest that detoxification rates are slowed at low metabolic levels. Certain antagonism to joint action was noted when insects were fumigated at the peak of O2 debt repayment after preconditioning.