Pheromone Studies on Astigmatid Mites: Recent Progress – A Comparison of Molecular Phylogeny, Distribution and Function of Female Sex Pheromone in Caloglyphus spp. (Acarina: Acaridae)

Abstract

Female sex pheromones, which elicit mounting behavior of conspecific males, were identified in 4 species of the genus Caloglyphus (Acarina: Acaridae). Although the sex pheromones are distributed over both males and females, they could be classified into two groups; one is an adult-specific pheromone, and the other is one that is detectable even in nymphal stages. In addition, in the adult-specific species, the pheromonal content ratios of female to male were found to be larger than those observed in the nonspecific species. The two types of pheromonal distribution were compared with phylogenetic relationships based on a portion of the mitochondrial cytochrome oxidase subunit I (COI) gene in the four species. The polymerase chain reaction was used to amplify the COI from the four mites, with primers used in spider mites (Tetranychidae). Fragments of the COI (453 bp) were obtained for the three species. The phylogenetic tree, based on the COI sequences, was inferred using a maximum parsimony method. Analysis of the pheromonal distribution within this phylogenetic framework agreed with the hypothesis that the mite sex pheromone evolved from a common compound, which originally functioned as a male sexual excitant, into a biologically active, sex linked specific one.