S. Mahunka szerk.: Folia Entomologica Hungarica 46/2. (Budapest, 1985)

FOLIA ENTOMOLOGICA HUNGARICA ROVARTANI KÖZLEMÉNYEK XLVI. 2 1985 p. 153-168 Flies (Diptera) of pasturing cattle: some new data and new aspects By L. PAPP and P. GARZO (Received 24 January, 1985) Abstract: Results of a wide-ranging study of the flies of pasturing cattle in Hungary are given. Data of 11, 800 dipterous specimens (reared from cattle droppings, netted from cattle and from their environs) are summarized in three tables. The authors collected flies around the eyes of tethered cattle by a new type of aspirators. It was found that the true size and dominance of the Diptera populations can only be estimated by rearing imagos from cattle droppings. It was noted that there are populations of numerous obligate coprophagous fly species (first of all of the families Sepsidae and Sphaeroceridae), which play an important role in the decomposition of cattle droppings. The dominance of the Haematobia larvae in droppings is very low (some tenths of a percent); the authors advance arguments to prove that the only reasonable control strategy is the extermination of their imagos. The role and impontance of larval and imaginai populations of Musca autumnalis are discussed in detail. In Hungary the emergence ratio of Musca autumnalis is 0.5 specimen per g dry weight of cattle droppings from the end of spring to the beginning of autumn, their larvae embody the most important larval population in the rapid decomposition of droppings. On the basis of new data an estimation was made for the determination of the fraction of the imaginai populations of Musca autumnalis, which is on the bodies of cattle at a given moment: this is 0.1 to less than 1 %, probably about 0.5 %. A trial is made for the first time to evaluate the importance of the imagos and of the larvae developing in droppings synchronously. Any application of nonselective larvicides on pastures is strongly rejected. Introduction A great majority of the specimens of the hematophagous and secretophagous flies wexing cattle by sucking their blood and discharges and a majority of these dipterous species are developing in cattle droppings; see e.g. PAPP (1985). The efforts for control of ectoparasites of farm animals have produced considerable results, so it is even more striking that no effective methods have hitherto been developed against these flies. This rather straight forward statement can be proved by anyone who has ever seen the mass occurrence of those fly imagos on cattle of a herd in summer. This is the present situation though taxonomical studies on pasture flies and investigations for their chemical control and other control methods had and have been in progress, and not without results.