OVIPOSITION AND DEVELOPMENT OF FACE FLIES IN DUNG FROM CATTLE ON HERBAGE AND SUPPLEMENTED HERBAGE DIETS

Dung was collected from Angus cattle (Bos taurus L.) fed (ad libitum) hays of endophyte-free (EF) and endophyte (Acremonium coenophialum Mor gan-Jones and Gams) infected (EI) tall fescue (Festuca arundinacea Sch reb.), smooth bromegrass (Bromus inermis Leyss.), red clover (Trifoliu m pratense L.), alfalfa (Medicago sativa L.), and alfalfa-smooth brome grass (1:1 w/w) and green-chopped Kentucky bluegrass (Poa pratensis L. ). Samples of dung were subsequently collected from the same animals o ffered the same herbage diets supplemented each day with ground maize (Zea mays L.) kernels at 0.35 kg per 100 kg body weight. Dung from bot h sources were used in bioassays to establish oviposition preferences of face flies (Musca autumnalis De Geer). When offered dung from herba ge diets, face flies deposited 38.3% of their eggs on dung derived fro m EF tall fescue diets, 9.9% on dung from EI tall fescue diets, 21.0% on dung from alfalfa diets, 7.4% on dung from red clover diets and 22. 8% on dung from alfalfa-bromegrass diets. Face flies avoided ovipositi ng in dung from cattle ingesting bromegrass hay and Kentucky bluegrass green-chop. Supplements increased oviposition preference of face flie s for dung from cattle ingesting Kentucky bluegrass greenchop to 19.1% at the expense of oviposition on dung from cattle ingesting alfalfa h ay diets (4.5%), otherwise, they had little effect on oviposition pref erence ranking. Growth and development of first instar larvae of face flies was also measured in bioassays of dung from cattle on herbage an d supplemented herbage diets. The presence of endophyte reduced pupati on in dung from cattle on tall fescue hay diets from 86.3 to 79.8% and from 90.1 to 73.2% in dung from cattle on supplemented tall fescue ha y diets. Pupal liveweights averaged 27.5 mg on dung from cattle on EF tall fescue diets, 22.1 mg from dung of cattle on EI tall fescue diets , 22.2 mg from dung of cattle on supplemented EF tall fescue diets and 24.0 mg from dung of cattle on supplemented EI tall fescue diets. Ecl osion and the sex ratio of adults were not affected by dung from cattl e on different source diets.