Cattle biting louse, Bovicola bovis (Mallophaga: trichodectidae), phoretic on the horn fly, Haematobia irritans (Diptera: Muscidae)

Adult horn flies, Haematobia irritans (Linnaeus), were collected from purebred Angus and Hereford cattle in the vicinity of College Station, Texas, during the spring and summer of 1975 to supplement laboratory production of ova needed for routine bioassay procedures. During the subsequent separation of horn flies from other fly species, 3 individuals were observed bearing phoretic cattle biting lice, Bovicola bovis (Linnaeus). One adult female louse and 1 nymph were attached by their mandibles to the abdominal integuments of a male and a female horn fly, respectively. A 3rd specimen, also an adult female, was observed unattached on the thorax of a female horn fly. Although peak population densities of these 2 bovine parasites occur on the host at different times of the year and only 3 such associations were observed among several thousand horn flies examined, this previously unrecorded mallophagan phoretic relationship (Keirans, 1975, J. Med. Ent. 12: 476) may allow the cattle biting louse a secondary, although minor, mode of dispersal