Stylopized hornets (Vespa, Vespidae) as preferred hosts of the parasitic mite Charletonia southcotti (Erythraeidae, Acari)

Parasitic mites have thus far been recorded only rarely from vespine wasps. We found larvae of the erythraeid mite Charletonia southcotti feeding on hornets, mainly Vespa analis workers that had been collected with bait traps. The mite seemed to prefer hornets stylopized by Xenos spp. as hosts to non-stylopized individuals, since in collections made over 7 years, 22 of 267 V. analis stylopized workers had larval mites, whereas there were none on 297 non-stylopized workers. The number of mites on a single host varied from one to five. The larval mites nearly always occurred in gapped spaces between tergites occupied by male Xenos puparia, and the mites’ engorged bodies showed that they did in fact feed on the hosts. We investigated the possibility that stylopization provided the mite with a suitable feeding place by opening gaps between the hornets’ tergites.