Sperm Reception and Egg Production of Mating-Interrupted, Single-Mated, and Multiple-Mated Females of Neoseiulus californicus (McGregor) at Different Temperatures (Acari: Phytoseiidae)

Abstract

Sperm transfer during the mating process and subsequent egg production were observed in a predaceous mite species, Neoseiulus californicus, at 18, 25, 30, and 35°C with a photoperiod of 16L:8D. Mating was disrupted at predetermined time points, and female egg production was counted daily. In addition, other females were allowed to mate repeatedly with new males throughout the oviposition period, and egg production was observed. To quantify the volume of sperm transferred from males to females, mated females were sacrificed and mounted immediately after copulation, and the diameter of the spermatophore within the female spermatheca was measured. The results indicated that both sperm volume and egg production increased with mating duration at all temperatures. However, the engorgement of female spermatheca by a spermatophore and subsequent female egg production began at an earlier stage of copulation (after a shorter mating duration) under higher temperatures. Multiple-mated females often had more than one spermatophore in their spermatheca, which was never observed in single-mated females, and the former laid more eggs than the latter at all temperatures. However, total egg production by multiple-mated females did not differ at 25, 30, and 35°C. The reproductive characteristics of N. californicus and their significance to the mite's life history are discussed from the perspective of biological control of one of their primary prey species, spider mites.