Reproductive Rates in the Citrus Red Mite, Panonychus citri (Mcgregor), Under High Temperature Conditions with Daily Fluctuations

Abstract

Near the natural temperature in summer or under more extreme temperature conditions, the intrinsic rates of natural increase (rm) of the citrus red mite, Panonychus citri (Mcgregor), Were remarkably high and ranged from 0. 207 to 0. 277. Under daily fluctuations of the temperature within the range of 27°C (16hr)-36°C (8 hr) in a day, the survival rate of P. citri was the lowest among the various temperature conditions. This phenomenon was ascribed to the low level of hatchability of the eggs (about 70%), and the decrease in the longevity of the adult females. But, there was no significant difference in the number of eggs laid per day between conditions characterized by daily fluctuations of temperature within the range of 27°C (16 hr)-36°C (8 hr) and the constant temperature of 25°C. Under the extreme temperature condition of 37°C for 6 hr in a day, a large number of eggs were laid. These results showed that high temperature conditions as those prevailing in mid-summer did not inhibit the reproduction of P. citri. © 1986, JAPANESE SOCIETY OF APPLIED ENTOMOLOGY AND ZOOLOGY. All rights reserved.