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Zum Überwinterungsverhalten der Tannenläuse der Gattung Dreyfusia (Hemipt., Adelgidae) 1
Author(s) -
Eichhorn O.
Publication year - 1962
Publication title -
zeitschrift für angewandte entomologie
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.795
H-Index - 60
eISSN - 1439-0418
pISSN - 0044-2240
DOI - 10.1111/j.1439-0418.1962.tb04097.x
Subject(s) - instar , aphid , biology , larva , overwintering , genus , hibernation (computing) , zoology , botany , mathematics , state (computer science) , algorithm
Summary Investigations during the years 1953–1962 in the Black Forest and in Switzerland proved, that the different species of the wooly aphid genus Dreyfusia show a different way of hibernation. D. piceae hibernates nearly exclusively as L 1 (first instar larva) and thus holds a special position amongst the four species investigated. Of D. nüsslini , f. typica und f. schneideri more than 75 per cent hibernate as L 2 and less than 10 per cent as L 1 . On Abies nordmanniana D. nüsslini , f. typica hibernates nearly exclusively as L 3 . D. merkeri taking the average of all samples hibernates with more than one third of the individuals as L 1 and with about 45 per cent as L 2 . The rate of third instars varies between 1–37 per cent. D. prelli is the only species which developes during normal winters and partly commences egg laying already in January. Exceptions from this overwintering behaviour and their possible reasons are discussed.