S. Mahunka szerk.: Folia Entomologica Hungarica 43/1. (Budapest, 1982)

In 1980 a notable decrease both in the counts and in the biomass values could be observed (15.31 x 10

6 ind. ha-1 and 1.90 kg ha-1 in dry weight). Maximal weight of the larvae, which have mining habits, was 1.1-1.3 mg, while average weight of the larvae just before pupation was 0.7 mg. The larvae consumed almost five times their own weight expressed in wet weight in 1977 and nearly ten times their own weight in 1979. Consumption values in wet weight were 44.7-385.4 kg ha-1 and in dry weight 17.6-153.8 kg ha-1 in these years. Mining larvae consumed 8.9-79.2% of the leaves of Cornus mas shrubs living in this territory. From the calculated ecological capacity values it appears that the assimilatory capacity is fairly good (52.9-91.3%), while the production capacity and the excretion index are relatively small. The respiratory capacity is strikingly high which can probably be explained by the larvae's habits. REFERENCES AXELSON, B. (1977): Applicability of laboratory measurements of bioenergetic efficiencies to field population;; i

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Oszt.Közi., _16: 11-25. JAKUCS, P. (1978): Environmental-biological research an oak forest ecosystem in Hungary. "Sikfokut Project". - Acta biol.debrecina, 15: 23-37. KACZMAREK, M. and WASILEWSKI, A. (1977): Dynamics of numbers of the leaf-eating insects and its effect on foliage production in the "Grabowy reserve in the Kampinos National Park", - Ecol.Polska, J25(4): 653-673. KÁRÁSZ, I (1976): Shrub-layer phytomass investigations in the Quercus petraea - Qu. cerris ecosystem of the Sikfokut research area. - Acta bot.hung., 22: 79-84. K LEIN ER T, J. (1978): Injury of foliage of woody plants by leaf-eating insects. - Biológia (Bratislava), 33_(2): 119-125. MATTSON, W.J. and ADDY, N.D. (1975): Phytophagous insects as regulators of forest primary production. - Science, 190: 515-522. NAKANO, K. and MONSI, M. (1968): An experimental approach to some quantitative aspects of grzing by silkworms (Bombyx mori). - Jap.Journal of Ecology, L8: 217-230. SZOCS, J. (1964): Megfigyelések a Lithocolletis nevelése közben (Zuchtbeobachtungen über Lithocolletis-Arten). - Folia ent.

hung., 17: 282-293. SZOCS, J. (1977): Lepidoptera-aknák és -gubacsok (Hyponomia et cecidomia Lepidopterorum). Magyarország Állatvilága (Fauna Hungáriáé) 125: 1-424. VARGA, Z., LAKATOS, Gy. és MARES, M. (1976): A tömeges lombfogyasztó Lepidopte ra-k szerepe a sikfőkuti cseres-tölgyes ökoszisztémában. - XII.Biol.Vándorgyűlés, Debrecen, 13: 199-214. WITKOWSKI, Z. and KOSIOR, A. (1974): Energetics of the larval development of the leaf roller moth, Tortrix viridana L. (Lepidoptera: Tortricidae) and an estimate of the energy budget in caterpillar development of other insects feeding on oak leaves. - Studia Natura, 9: 93-103. Author's address: Dr. L. SZABÓ Department of Ecology Kossuth Lajos University Debrecen H-4010 Debrecen HUNGARY