RESPIRATORY RESPONSE OF 5TH-INSTAR CODLING MOTH (LEPIDOPTERA, TORTRICIDAE) TO RAPIDLY CHANGING TEMPERATURES

Fifth-instar codling moth, Cydia pomonella (L.), larvae were exposed t o 10 simulated heat treatments of apples and pears and CO2 levels were monitored as a measure of respiration. Marked increases in respiratio n rates (mu l CO2/mg/min) were noted during these treatments. Respirat ion peaked between 3.5 and 4.8 mu l CO2/mg/min; the amount of time to peak respiration depended on the heating rate and was correlated to th e LT95. No differences were observed between male and female larvae in the timing of the peaks of CO2 production. In treatments where mortal ity occurred, CO2 levels dropped to zero, but only after a considerabl e time after death. Respiratory recovery rates, the time it took for C O2 levels to return to normal, were recorded after treatments at time points where CO2 production reached 3/4 and maximum peak. Respiration rates at constant temperatures were recorded within the range of 10-30 degrees C. Q(10)over this range was 1.49, whereas Q(10) was the great est, 2.54, between 10 and 15 degrees C.