Copulation duration, sperm transfer and reproduction of the two closely related phytoseiid mites, Neoseiulus womersleyi and Neoseiulus longispinosus (Acari: Phytoseiidae).

ABSTRACT

The effects of copulation duration on reproduction were studied in two important biological control agents, Neoseiulus womersleyi (Schicha) and Neoseiulus longispinosus (Evans), to better understand their reproductive potential. The number of eggs produced was significantly and positively related to the copulation duration in both species. Egg production was observed even in females which experienced only 15 min of copulation and increased as copulation period increased in both species. Both pre- and post-oviposition periods of N. womersleyi and N. longispinosus decreased with the increase of copulation durations, and they were significantly different between the two species. Copulation duration had no effect on the female adult longevity of N. womersleyi and N. longispinosus, but N. womersleyi showed higher adult longevity than N. longispinosus. Fecundity remarkably increased in both species when the copulation period exceeded 90 min. The size of the spermatophore inside the spermathecae increased in proportion to the copulation duration in both species. Fecundity was consistent with the sizes of the spermathecae and spermatophores. When copulation was extended, males first filled one spermatheca and then filled the other. The results obtained in this study suggest that copulation duration had similar effects on egg production in N. womersleyi and N. longispinosus. Egg production depended on the quantity of sperm transferred during copulation. The two species have similar reproductive potentials and mating properties under laboratory conditions.