Die Fichtengespinstblattwespe, Cephalcia abietis L., als gefährlicher Bestandes- und Kulturschädling in Österreich

Abstract

The Spruce Pamphilid, Cephalcia abietis L., a pest dangerous to young and old spruce stands in Austria

Continous of the spruce, fir and beech growth area on ranges in the northeast (from 1966 onwards) and southwest (from 1970 onwards) of the Waldviertel (Lower Austria) have shown that in connection with other unfavorable effects (rime) this species can become a dangerous pest. In areas reforested with apruce - on clearing which have resulted from feeding -already in the year of reforestation and in the following one eggs were deposited. Feeding took place on old needles and on needles of the May shoots. Retrogradation began after two stages of eruption on the southern and after one on the northern elevations. It was found out that by unfavorable environmental condition emergence of 200 imagines per sqm to obvious and even high losses. In initial populations of the same feeding period in which increases of populations by migration did not take place, generations of 1, 2, 3 and 4 years could be proved. Factors of the biotic environment resistance (parasitic insects, bacteria, fungi) have been of importance for the reduction of young larvae in the soil only in the third year of retrogradation: in the second year virus diseases have caused in the southwest considerable dying of the young larvae in the crowns.

Phosphorus insecticides, applied with ULV-methods, killed 50–80% of the young larvae. Lindan was used with success for the treatment of forestations.