Über eine Massenvermehrung der stahlblauen Kieferngespinstblattwespe,Acantholyda erythrocephala Chr., im Steinfeld, Niederösterreich, in den Jahren 1964–1967

Abstract

The present paper reports on an outbreak of the False Pine Webworm (Acantholyda erythrocephala L.) in the Steinfeld of Lower Austria, from its detection in July 1964 up to swarming of wasps in April 1967. The course of gradation and resulting damages are described, and data obtained on development, manner of life, and mortality given. In plantations of predominant Austrian Black Pine (Pinus nigra ssp.austriaca) and Scots Pine(Pinus silvestris) the former, too, was attacked though to a considerably lesser extent than the latter. Among mortality factors observed, most important was a nuclear polyhedrosis, which, during the first year of outbreak, killed numerous pseudocaterpillars, but sensibly diminished in lethal effect in the further course of calamity. In connection with the outbreak ofAcantholyda erythrocephala, some other pest occurrences in the plantations are mentioned. A possible competition effect of a previous outbreak ofNeodiprion sertifer, lasting several years, and one ofDendrolimus pini L., lasting two years, resulting in inhibitions of a more precocious development of the outbreak ofAcantholyda erythrocephala, and in prevention of a nascent gradation ofPanolis flammea by the multiplication ofAcantholyda taking its course, is particularly referred to. Control experiments were done with the fumigant “Kerfex-Nebelkorper/rd. An effective control by this product, too, must be carried out soon after emerging of young larvae.