Boros István (szerk.): A Magyar Természettudományi Múzeum évkönyve 51. (Budapest 1959)

Kovács, L. ; Gozmány, L.: Data to the quantitative relations of the Lepidoptera of the Alderwood Marshes in Ócsa, Hungary

instance, there was one which was collected 6 times only, and two others which were captured 7, that is, 8 times (cf. details on Table III). The studying of oecological levels is an extraordinarily difficult task in the case of lepidopterous imagos. Their locomotion is done preponderantly by flying, during which they are usually in the higher levels. They have no constant level of feeding, because the imagos will look up nectariferous flowers or even artificial nourishing substances both in higher and lower levels. For the most part, their most stable level-connections may be regarded the one relating to their hiding places, insofar as the imagos of certain species, indeed, of some families adhere to preponderantly one and the same level. In this regard, we had several observations also in this place, namely, a part of the imagos of nocturnally active species could be disturbed exclusively or mainly from the low shrubbery during the daytime hours, whilst those of some other species appeared by our shaking or tapping of the high foliage level of the trees. Of the species over 1%, the following could more or less regularly be disturbed from the lower levels : if. ruralis, C. pusaria (this was sitting also on the leaves of the alder trees), E. alternata, X. ferrugata, 0. nubilalis, S. biselata, and C. amataria. We found especially two Boarmid species on the trunks of the trees (E. bistortata and Ae. punctulata). The bigger Boarmia species, among them the frequent punctinalis, were invisible in the daytime, and females fly but exceptionally onto the light of the lamp. From this, one may conclude that they abide in the foliage level, hardly penetrated by the light of the lamp, so that only the more vagrant males get into the range of the light. At all events, these problems require further study, but it seems indubitable that the imagos of many species are, as far as concerns the selection of their hiding places, indifferent to levels. As was mentioned above, there were three lepidopterous species which played a salient role during our surveys, namely P. muscerda, E. griseola, and H. ruralis, with dominancy values 16,1, that is, 6,8 and 5,1. In the following discussion, we endeavour to examine the results of the single surveys one by one for the sake of establishing the rate of changes in the dominancy values of these species during the several surveys, and to find out whether there be certain regularities in the partial results. 1. 10 June, two days after a full moon, a cold night. We observed 71 species. Of these the dominancy values were the following : P. muscerda 9,7 : A', metaxella 7,3 : B. punctinalis 7,3 ; A. reticulana 5,4 ; those of the others did not exceed 5. Of the subdominants, the d value of L. griseola was 0,02 ; that of H. ruralis 4,7. 2. 17 June, before a new moon, a mild night. We observed 117 species. The d values were as follows : H. ruralis 21,3 ; P. muscerda 7,7 ; E. griseola 5,7 ; 0. nubilalis 5,6 ; those of the others did not exceed 5. 3. 1 July, after first quarter, a warm night. Only one lamp was active, and we observed 109 species. The d values were as follows : E. bistortata 14,9 ; E. griseola 13,9 ; E. alternata 6,1 ; S. punctinalis 5,4 ; those of the others did not exceed 5. 4. 8 July, one day after full moon, a mild night. We observed 96 species. The d values were as follows : Ae. punctulata 14. E. bistortata 9,6 ; E. griseola 9,1 ; X. ferrugata 6,7 ; P. muscerda 5,6 ; those of the others did not exceed 5. 5. 15 July, at last quarter, a warm night, with a squall after midnight, survey discontinued. We observed 186 species. The d values were as follows. E. griseola 9,3 ; E. alternata 7 ; II

. rostralis and E. bistortata both 5,9 ; those of ihe others did not exceed 5. 6. 22 July, new moon, a stronger nocturnal loss of temperature, to be felt also in the forest. We observed 178 species. The d values were as follows : E. griseola 20,3 ; E. zinckenella 7,8 ; those of the others did not exceed 5. 7. 29 July, about first quarter, a sudden fall in temperature in the afternoon, the temperature being 23,5° C at 1500, clear at midnight, temperature 23° C, then overcast, temperature