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

slowly mounting to 13,5° C. Psychrometer shew 70% at dusk, attaining 99% during the night. We observed 139 species. The d values were as follows : E. griseola 10,2 ; P. similis 6,3 ; Ph. potatoria 6,2 ; P. lugdunaria 6,1 ; those of the others did not exceed 5. 8. 4 August, before full moon, a mild night. We observed 156 species. The d values were as follows : E. griseola 8,4 ; Ph. potatoria 7 ; P. muscerda 6,4 ; C. amataria 5,4 ; those of the others did not exceed 5. 9. 12 August, before last quarter, a warm night. We observed 140 species. The d value of P. muscerda was 28,3 ; that of E. alternata 7 ; those of'the others did not exceed 5. 10. 19 August, before a new moon, a mild night. We observed 144 species. The d value of P. muscerda was 42,8 ; that of C. pusaria 10,5 ; those of the others did not exceed 5. 11. 26 August, before first quarter, a cold night, with a formation of dew in the more open places, fields covered by mist at morning. We observed 84 species. The d values were as follows : P. muscerda 27,6 ; H. ruralis 14,2 ; S. dimidiata 6,7 ; those of the others did not exceed 5. 12. 2 September, before full moon, a mild night, overcast after midnight. We observed 73 species. The d values were as follows : P. muscerda 24,6 ; H. ruralis 19,5 ; S. dimidiata 9,2 ; X. ferrugata 6,8 ; S. biselata 5,9 ; those of the others did not exceed 5. 13. 12 September, at last quarter, a squall in the afternoon, a cold night. We observed 61 species. The d values were as follows : H. ruralis 30,8 ; P. muscerda 18,7 ; S. biselata 5,6 ; those of the others did not exceed 5. 14. 38 September, at new moon, a cold night, temperature about freezing point at morning, locally frostbite on plants, a deep fog. Moths flying practically only in the evening hours. We observed 24 species. The d values were as follows : S. dimidiata 17,5 ; P. muscerda 15

;

5 ; A. evonymaria 6,7 ; those of the others did not exceed 5. With regard to the low individual numbers, these values are more or less only of an informational nature. Of the above data, we may establish the followings with reference to the dominant, that is, subdominant species. 1. P. muscerda was frequently a dominant, that is, subdominant species during our surveys, and it had exceedingly high d values during a part of the flying time. It was a dominant species on 5 occasions, namely once at the beginning of June, and four times from the middle of August till the beginning of September ; it was a subdominant on one occasion before the period of its dominancy, a subdominant on one occasion before the period of its dominancy and four times afterwards it (on the basis of a survey in 1953, it is a dominant already on the turning of May and June). 2. E. griseola was a dominant on some fewer occasions : four times ; namely from the middle of July till the beginning of August. Its d values were lower ; indeed, they were so much approached by those of one or the other species on two occasions that one may talk of condominancy. It was a subdominant on two occasions only. 3. H. ruralis was a dominant two times only : at the beginning of June and September. Its d value was very high on one occasion; it exceeded 30. It was a subdominant two times. It can be established indubitably from the data of the surveys that the dominant species has two generations, of which, however, the first is but moderately populous and contributes only slightly to the augmentation of the totalled d value. The more rich in individuals is the second generation, which alone could assure the dominancy of the species. — The first subdominant species has a single generation, but it is very populous and is on the wing for a long time. — And though the second subdominant has two generations, they are of a short duration and rather less populous than those of the first two. As is to be seen, these three species combined were dominants during 11 surveys. On the three remaining occasions, there were other dominant species, namely