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Effects of Dimilin on adults and eggs of Agelastica alni L. (Coleopt., Chrysomelidae) In consequence of treating adults ofA. alni with Dimilin the median number of egg clusters per female decreased about by a half. The absolute number of eggs was not affected. On the contrary the number of fertilized eggs as well as the number of hatched larvae decreased considerably. In the controlbreedings there were no differences between the quote of fertilized eggs and that of hatched eggs, but the treatment of adults with Dimilin resulted in a great difference between these quotes. The behaviour of male and female adults did'nt show changes. The eggs were susceptible to Dimilin, the young eggs more than the elder ones.  相似文献   

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Distribution and economic importance of the dermestid beetleTrogoderma variabile are quoted and the possibility of an introduction into Europe is stated. Hence the biology ofT. variabile shall be examined in detail. In this paper the author refers longevity of the adults at different temperatures (25, 30, 35 °C) and the number of eggs laid per female.  相似文献   

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Observations are given on phaenology and bionomy ofP. revestita in South Tyrol last years. The larvae develop exclusively within dead stumps of branches near the living tissue. The first attack shows secondary character but later the feeding can become primary. The time of flight occurred mainly in the middle of May. The quota of females amounted to 50% in the laboratory but only to 14% in the field. Apparently the males show more activity of flight than the females. The beetles swarm in the crowns of host trees about noon.  相似文献   

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Von allen einheimischen Baumarten liegen über die Bewurzelung der Kiefer (Pinus silvestris) die meisten Untersuchungen vor (Liese, 1926;Hilf, 1927;Vater, 1927;Laitakari, 1929;Wagenhoff, 1938). Das Interesse hierbei galt bisher besonders der Wurzelentwicklung auf Sandböden. In jüngster Zeit erfuhren die Erkenntnisse eine wesentliche Vertiefung durch Arbeiten vonEhwald (1948),Köstler (1956),Wagenknecht (1960) undKreutzer (1961). Trotzdem sind die Vorstellungen von der Bewurzelung der Kiefer auf verschiedenen Standorten, ihrer genetischen Veranlagung und ihrem Wachstum noch lückenhaft. Die folgenden Ergebnisse stammen aus Untersuchungen, die im Rahmen eines größeren Forschungsvorhabens über die Wurzeltracht der einheimischen Baumarten, an dem im Münchener Waldbauinstitut gearbeitet wird, erhoben wurden.  相似文献   

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