Myrmica aloba (Hymenoptera: Formicidae) hosts isolated populations of a hoverfly, a butterfly and an ichneumon species in NE-Portugal

Larvae and pupae of the obligately myrmecophilous social parasites Microdon myrmicae (Diptera: Syrphidae) and Maculinea alcon (Lepidoptera: Lycaenidae) were found using exclusively Myrmica aloba (Hymenoptera: Formicidae) host ants in NE-Portugal. Ichneumon eumerus (Hymenoptera: Ichneumonidae) was also found developing in Ma. alcon pupae in nests of My. aloba at the same site. These are the first records of Mi. myrmicae and I. eumerus for Portugal, and from My. aloba nests. Earlier records that My. aloba is the only known host ant of Ma. alcon in Portugal are confirmed. Further studies on the biology of these isolated peripheral populations are necessary for their well-planned protection.