Influence of Hexythiazox Resistance on Life History Parameters in the Citrus Red Mite, Panonychus citri (McGregor)

Abstract

The life history parameters concerned with population growth were studied in the citrus red mite, Panonychus citri (Mcgregor), Among genotypes, or the hexythiazox resistant Haibara-R (RR), the susceptible Haibara-S (SS) and their hybrids (SR and RS) which are the same origin from a citrus orchard at Haibara-cho in Shizuoka Prefecture, Japan. The difference in the intrinsic rate of natural increase (rm) among genotypes was slight at 25°C where rmdecreased in the order genotype SS (0.2110), SR (0.2098), RS (0.2042), RR (0.1996). However, the fitness disadvantage was severe at 35°C where rmwere 0.1187 and 0.0123 in SS and RR, respectively. At any mite age at 25 and 35°C, reproductive values in RR were smaller than those in SS. The reduction of values of rmand at both 25 and 35°C seemed to be ascribed to the significantly shortened longevity and reduced fecundity of adult females in RR, compared with those in SS. © 1995, Pesticide Science Society of Japan. All rights reserved.