Janus Pannonius Múzeum Évkönyve 34 (1989) (Pécs, 1990)

Természettudományok - Nógrádi U., Sára–Uherkovich, Ákos: The Trichoptera fauna of the Zselic Downs, Hungary

28 S. NÓGRÁDI-Á. psyche futvipes Çurt., H guttata Curt., and H siltalai Döhler. Most of the collected Hydropsyche species are frequent. These caddisflies - together with their undetermined females - can be dominant or subdominant (see also Nógrádi and Uherkovich 1988). Out of the 31 species of the five smaller families (Pofycentropodidae, Psychomyidae, Ecnomidae, Phryganeidae and Brachycentridae) 15 were recorded. The bulk of them comprises wide-spread and rather frequent species, Brachycentrus subnubilis Curt, and Agrypnia pagetana Curt, proved to be rare in the region. The largest family, Limnephilidae comprises 53 species in Hungary, of them 29 species were caught. There are some rarities amongst them: Limnephilus elegáns Curt., Phacopteryx brevipennis Curt., Rhadicoleptus alpestris Kol. and Platyphylaxfrauenfeldi Brau. Some comments are given on them in the previous section. Two goerids and 2 lepidostomatids live here. Lasiocephala basalis Kol. is a rarity in Hungary. 16 species of the 33 Hungarian leptocerids were captured. Some of them proved to be very common. They live in large masses in fish ponds, e. g. Ceraclea dissimilis Steph., Oecetis ochracea Curt., Oe. notata Ramb., Setodes punctatus Fabr., Leptocerus tineiformis Curt. Two species of Beraeidae and 1 of Sericostomatidae occur here. No odontocerid species was collected. 2. Some remarks on ecology Owing to the hydrography of the examined region the species particularly favouring rapid mountainous streams are missing. Only some species having such character occur here, but they are rare : Crunoecia irrorata Curt., Rhyacophila fasciata Hagen, Hydropsyche saxonica McL., Potamophylax nigricornis Pict. and Chaetopteryx major McL. A large proportion of the species belongs to the group of species favouring slow streams and rivers. These are the most wide-spread species of the Zselic Downs, because of the dense network of streams. Such species are the hydropsychids, several limnephilids and some others. They have 10-15 locality data from this area. The largest quantity of caddisflies comprises leptocerids. Some of these breed in huge masses in the constructed fish ponds. The species characteristic of stagnant waters have spread and became frequent or common in the past decades owing to the establishment of several new fish ponds. 3. Dominant species In Table 10 we arranged the species of the most important collecting sites (light traps and personal collections) in the sequence of dominancy. The species reaching more than 1 per cent value are listed here. UHERKOVICH As it has been mentioned, the Hydropsychespecies often become dominant species, in 7 times of the 10 tables, and 2 times they are subdominant. Twice Ecnomus tenellus Ramb. reached an extraordinarily high dominancy (at Almamellék, Sasrét with 94.19 p. с and Csertő with 62. 42 p. a). Ceraclea dissimilis Steph. is often among the most dominant species, sometimes it is absolutely dominant (Somogyapáti, 73.33 p. a). 4. Phenology Hereunder the species were groups according to their yearly activity: a. Spring species. These are on the wing in AprilMay, or a little later. They survive the summer and autumn dry periods in the larval stage. Several such species live in small brooklets which dry out in the summer, e. g. Lithax obscurus Hagen, Notidobia ciliaris L., Beraea pullata Curt., Beraeodes minutus L. b. Summer species. This small group includes only a few species which are on the wing in the middle of summer: e. g. Hydropsyche ornatula McL. and Setodes punctatus Fabr. Main being active in July. с Autumn species. They hatch in autumn or in late summer. Their activity period is sometimes very short (Ironoquia dubia Steph.), though usually it lasts for one or two months (Potamophylax rotundipennis Brau., Anabolia furcata Brau., Halesus tesselatus Ramb., Chaetopteryx major McL.). A typical autumn species is the very rare Platyphylaxfrauenfeldi Brau. d. Species with continuous hatching and activity. Most of these can be on the wing from May or June till August or September. The time of hatching depends on the warming up of waters or on some other circumstances. Such species are the Hydropsyche, several leptocerids and polycentropodids, and perhaps the hydroptilids. Their activity graph is not regular. e. Summer diapause. Almost all Limnephilus, also Grammotaulius, Glyphotaelius, Stenophylax and phryganeid species have a longer or shorter interruption period in their activity. This diapause lasts for 2-3 months. The Stenophylox species have the longest interruption (from the end of June till the end of September or middle of October). Some species, like Limnephilus hirsutus Pict., L. extricatus McL., Trichostegia minor Curt., Agrypnia varia Fabr., have a relatively short diapause (4-6 weeks). The summer rest sometimes may be broken by a cool, rainy weather in the afforested regions, mostly in the mountains. Some examples of the activity of the most frequent species are depicted on Figs. 9-11.