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

of this family are likely to be the most important group of the obligate coprophagous flies in our country. The group which is richest in species among the obligate coprophagous flies is the family Sphaaroceridae. In the present studies nine sphaerocerid species were reared but more than 30 species have been found to develop in cattle droppings here. The species Coproica lugubris (Haliday, 1836) is a dominant species in all areas of the country, the species Lotobia pallidiventris (Meigen, 1830) is abundant locally. Owing to their high species-diversity, and, in some places the very high abundance of the specimens of Coproica lugubris

. the sphaerocerids as a group are not insignificant in the decomposition of cattle droppings but because of their small individual mass (see PAPP, 1971), also the quantity of the matter decomposed by their activity lags behind that of the sepsids. The anthomyiid species Paregle clnerella (Fallén, 1825) Is significant among the obligate coprophages, too. The individual dry weight of its larvae is 2 mg or slightly more, the number of its individuals is rather high in some places (Table 1: No. 31), thus as regards the dominance In weight in lowland pastures of Hungary in summer, these values of the populations of Paregle cine- rella are usually the third after those of Musca autumnalis and Sepsis thoracica. Though the individual numbers of Neomyia corniclna (Fabricius, 1781) (in earlier literature: Orthellia caesarion (Meig.)) are lower, i.e. this species rarely exceeds 10 % of dominance in individual numbers but in some cases (e.g. Table 1: Nos 24-28, samples from Izsák), In a given place, also its individual numbers are considerable. It is important however, that its individuals are large (the individual dry weight of the larvae is 10-15 mg), this is why a considerable amount of matter can pass through their guts. In this respect the importance of its larvae is similar to that of Musca autumnalis, moreover, the larvae of Neomyia - owing to their bigger individual mass - can consume individually even more. The species of Haematobia (horn flies) In Hungary the genus Haematobia sensu lato (so including Haematobosca) has four species: Haematobia (Haematobosca) stimuláns

, which lives here only in the pastures of our mountains; Haematobia (Haematobosca) atripalpis

, which occurs only locally (e.g. in Apajpuszta) owing to hitherto unknown reasons, i.e. it can be significant at most in places of its occurrence. In the pastures of lowland and hilly areas of Hungary the populations of Haematobia irritans (Linnaeus, 1758) and Haematobia titillans (Bezzi, 1907) form masses; specimens of Haematobia ir ritans has been found in a much higher abundance in all of the hitherto study areas. According to our experience the ratio of the specimens of Haematobia titillans does not reach even 10 %, its mean value is about 5 %. The distribution of the imagos of H. titillans on the bodies of cattle Is different from that of H. irritans: former ones are found on the parts with thinner skin, i.e. on the base of tail, on the base of horns, on tits, etc., while imagos of Haematobia irritans are on all parts of the body. The present series of data corroborate previous findings that the dominance of the Haematobia specimens is surprizingly low in the flies developing in cattle droppings. In the samples from Izsák (Table 1) this dominance is only 0.20 %, in those from Mezőhék 1.72 %; from five samples taken in the Hortobágy National Park there was no emergence of Haematobia (PAPP, 1976), in Aranyosgadány (PAPP 1971) this value was 0.44 % among more than 12,000 dipterous specimens; i.e. in Hungary the specimens of Musca autumnalis developing in cattle droppings are 20 to 25 times more than specimens of the Haematobia species combined (see more below). The imagos of the Haematobia species remain on the bodies of cattle by day and night. The females leave cattle for a short period only, while they drop their eggs on the freshest possible cattle droppings (see e.g. Table 3: No. 3). The populations of the Haematobia species overwinter as pupae. At the end of September the sex-ratio is changing In the favour of the females (Izsák, 28th Sept.: H. irritans

: 43 â/61 $, H. titillans

: 2 ô

1

/

52 ç, see Table 2: No. 28); there are ripen or nearly ripen eggs in the abdomen of females; the larvae, which will overwinter as pupae, hatch from these eggs. The above statements can serve as bases for a reasonable control strategy of the Haematobia populations. Since the larvae of the Haematobia species amount only to a few tenths of a percent of the larval populations of the flies developing in cattle droppings, the application of non-selective larvicide compounds is not only hazardous but also rather ineffective. There is no selective larvicide at present anyway. Those, who are conscious of the danger that by destroying non-target larval populations thereby hazard, the decomposition of cattle droppings, usually argue, that the sus-