Life tables of the laboratory population of the peach fruit borer,Carposina sasakii Matsumura at different temperatures

In order to explore the effects of temperature on the population growth of the peach fruit borer, Carposina sasakii Matsumura, we investigated the developmental durations, survivorships, and/or fecundity of this pest in the laboratory under the conditions of 17, 20, 23, 26, 29 and 32(±1) ℃, RH 80%±7% and a photoperiod of 15L∶9D, and then constructed life tables of the laboratory population of the C. sasakii in each of the temperature except 32℃. The results showed that the developmental duration decreased with the temperature increasing from 17℃ to 32℃. The longest duration of the generation was 70.19 d observed at 17℃, the shortest was 27.42 d at 32℃, and the relationship between developmental rates and temperatures could be simulated by the Logistic model. The percentage of neonatal larvae bored into fruit increased with the temperature increasing, while the relationship between the percentage (y) of larvae exited from fruit and temperature (x) could be described by the equation: y=-0.5638x2+27.882x-269.18 (R2 = 0.9801, P0.01). The cocooning rate of larvae and the emergence rate of pupa differed insignificantly over the temperature of 17-29℃, but decreased sharply at 32℃. Adult lifespan and fecundity of the female decreased with the temperature increasing, and the highest mating rate of the female and population trend index were found at 23℃, but both the survival rate of immature stage and the intrinsic rate of increase were the highest at 26℃. Relationship between the generation survival rate (S), the intrinsic rate of increase (rm) and temperature (x) could be described by the equations: S=-0.073x3+4.626x2-92.019x+596.57(R2 = 0.9832), rm =-0.0008 x2+0.0409x-0.4438(R2=0.9851, P0.01). It is so concluded that temperature has great effect on the development of C. sasakii, and the most suitable temperature range for this pest is from 23℃ to 26℃, during which there are higher intrinsic rate of increase and higher index of population trend.