Structure of acarinaria in the wasp Allodynerus delphinalis (Hymenoptera: Eumenidae) and distribution of deutonymphs of the associated mite Ensliniella parasitica (Acari: Winterschmidtiidae) on the host

The adult eumenid wasp, Allodynerus delphinalis delphinalis (Giraud), had obvious acari-naria (mite chambers) on the propodeum, the second metasomal tergite, and the scutellum, harboring deutonymphs of the mite Ensliniella parasitica Vitzthum. The scutellar acarinaria, first described here in detail, were a pair of deeply invaginated chambers situated on both sides of the scutellum, connected to the outside via a very small orifice. The metasomal acarinarium, located on the base of the second tergite, had clear sexual dimorphism. In the female, it was an almost completely closed, capacious chamber, while in the male, it was a wide furrow overhung by a lamella that extended backward from the margin of the second tergite. Newly emerged female and male wasps had a total of 148 and 44 deutonymphs on average, respectively, in the acarinaria. In the female, the metasomal acarinaria supported the largest mite population, while in the male, the scutellar acarinaria were the principal mite chambers.