The Symbiosis of Acarid Mites, Genus Ctenocolletacarus (Acarina, Acariformes), and Stenotritid Bees, Genus Ctenocolletes (Insecta, Hymenoptera)

Abstract

Details of the life history of acarid mites of the genus Ctenocolletacarus have emerged from studies of nests of their hosts, Ctenocolletes albomarginatus and Ce. nicholsoni, and from rearing mites in the laboratory. The mites are closely associated with their hosts at all stages and their complete breeding cycle occurs in the hosts' sealed brood cells. Only the phoretic deutonymph leaves the cells. The mites, like their hosts, are univoltine. One to a few hypopi dismount from nesting females into each new brood cell and rapidly transform through non-mobile tritonymphs to adults of both sexes. Female mites oviposit on the ceiling of the cell during the host larva's early instars, giving rise to hundreds of larvae and then protonymphs by the time the host larva has completed feeding. Protonymphs metamorphose to hypopi once the host larva has defaecated and entered the prepupal phase. Hypopi remain with the dormant prepupa until the following season when they secrete themselves beneath the terga of the newly emerged adult bee. Circumstantial evidence, suggesting that hypopi are transmitted venereally between adult bees, is discussed. Adult, larval and protonymphal mites ingest pollen and the late protonymphal stage invades the faeces of the larval host. Sanitary control is a possible pay-off for the hosts.