INTEGRATED PLANT-PROTECTION IN FARMING-IN VESTIGATIONS INTO THE DIPTEROUS FAUNA ON CROP AREAS

Within the scope of the treatise about 'Integrated plant protection'' on the Lautenbacher Hof (district Heilbronn, Baden Wurttemberg, German y) there has been investigated comparatively the dipterous fauna of in tegrated and conventional managed fields of 1988-1990. Supplementarily to that there had been analysed the influence of organic manure and a lso of a hedgerow on abundance dynamics of the diptera. The imagos wer e registered by emergence traps, the larvae however by a modified siev e-flotation-method and by Berlese-Tullgren-extraction. With the help o f emergence traps there could be proved 46 717 individuals belonging t o 306 species and 47 families. The results of the extractions of the m odified sieve-flotation-method furnished proof of 17516 dipterous larv ae and dipterous pupae descending from 19 families. That variety could expanded up to 22 families by the Berlese-Tullgren-method. The differ ent cultivation influenced the physical soil parameters in an evident way. Following to that the distribution pattern of dipterous larvae in the soil varied a lot: in the integrated plot (I) the stratum of 0-10 cm, in the conventional plot (K) the stratum of 10-30 cm was prefered to populate in. All over the year on K there could be proved the phyt ophagous wheat pests Contarinia tritici, Sitodiplosis mosellana and Ha plodiplosis marginata in significant higher abundances. The density of larvae varied between 100-1400 Ind./m2 and month. The crop rotation a nd the climate exercised a stronger influence on dominances and abunda nces of the imagos than the way of cultivation. In the average 435-460 Ind./m2 and month emerged. Metopina oligoneura MIK, a polysaprophagou s scuttle fly of about 1 mm size, dominated by about 34 % of all emerg ed adults in the dipterous coenosis of Lautenbach. Organic manuring by wheat straw and sugar beet leaves raised the portion of saprophagous dipterous larvae. A hedgerow on the adjacant fields - in comparison wi th hedgeless fields - produced 2 to 3-times higher abundances of dipte rous imagos. In the boundary hedge/field a new species of sciarid fly - Corynoptera ignorata MOHRIG and FROESE - has been recorded. Some dip terous species showed an evident affiliation to specific biotopes.