Observations on the mite fauna associated with adult Stomoxys calcitrans in the U.K.

Adult females of the blood-sucking muscid Stomoxys calcitrans sampled between June and September 1993 from a cattle farm (n = 839) and from a pig farm (n = 542) in North-West England were examined for mites. Twelve species of mites from ten families and three orders were identified as follows. In the Prostigmata, Eryenetes sp., Family Ereynetidae and Pediculaster mesembrinae, Family Pygmephoridae. In the Astigmata, Procalvolia zacheri Family Saproglyphidae, Acarus farris, Family Acaridae, Bonomoia sphaerocerae and Myianoetus sp., Family Anoetidae. In the Mesostigmata, Macrocheles muscaedomesticae and Macrocheles subbadius Family Macrochelidae, Digamasellus sp., Family Digamasellidae, Halolaelaps sp., Family Halolaelapidae. Prodinychus sp., Family Uropodoidea and Thinoseius sp., Family Eviphididae. Mean infestation rates at the two sites (all mite species) for the entire sampling period were 31.6 +/- 13.9% and 19.8 +/- 3.6% respectively. 51% of synbovine flies sampled in July were infested with mites. Mean numbers of flies infested in August at both farms were significantly lower compared to other months. The presence of tritonymphs of Ereynetes sp. on S. calcitrans demonstrates for the first time that this life cycle stage is naturally associated with insects in the field. All mites were recovered from the ventral thorax and abdomen, and two or more species commonly infested individual flies. Associations of mites with their dipteran hosts are described and discussed.