Preliminary observations of ovoviviparity in the gall-forming mite, Aceria caulobius (Nal.) (Eriophyoidea: Eriophyidae)

Abstract

A study has been conducted on the ovoviviparous behaviour of females of Aceria caulobius (Nal.), a gall-forming eriophyid mite living on the stems of Suaeda fruticosa Forsk. Galls were collected at 2-week intervals from September, 1987 to May, 1988, and dissected to obtain a sample of live mites for microscopic examination. Live migrating mites from the shoots were also examined. Ovoviviparity was observed in females recovered from the galls and, in some instances, nymphs or chorion residues within their bodies. It is possible that in the case of individuals containing chorion remnants, the nymph may have emerged through the mother’s genital opening without harming her. The occurrence of females containing eggs in the cleavage phase indicates that embryonic development can commence within the female’s body. No eggs were found in migrant females. No relationship has been established between ovoviviparity in A. caulobius and the density of the gall population, the growth of the galls or the migration of the eriophyids.