Histiostoma blomquisti n. sp. (Acari: Astigmata: Histiostomatidae), a phoretic mite of the red imported fire ant, Solenopsis invicta Buren (Hymenoptera: Formicidae)

The new species Histiostoma blomquisti n. sp., associated with the Red Imported Fire Ant, Solenopsis invicta, is described by its deutonymph. A putative adult female is depicted. The deutonymphs only attach to female alates, dealates and queens of S. invicta. While queens may be covered by more than 200 deutonymphs over their entire bodies, the numbers of deutonymphs substantially differed between alates, dealates and queens, which are the preferred carriers, and the males and workers, which are usually not the phoretic hosts of these deutonymphs. It is assumed that the large amount of deutonymphs on queens may be a consequence of special conditions during nest foundings of monogyne colonies. Presence of deutonymphs apparently stimulates the cleaning behavior in workers; however deutonymphs are not removed during this procedure. This may be a consequence of chemical components produced in the opisthonotal glands of astigmatid mites that allow the mite to repel cleaning workers and remain strongly adhered to its carrier. It is unknown whether or not these mites affect the vitality of fire ant colonies.