Untersuchungen über die Beschädigung von Kiefernnadeln durch Scythropus mustela Herbst (Coleoptera: Curculionidae).

Abstract

There are discussed the results of studies on feeding habits of Scythropus mustela in-festing needles of Scots pine in a 8 years old plantation near Banska Stiavnica (Central Slovakia) in 1963. Based upon laboratory feeding experiments and measuring injured needles in the field there was found that the beetles eat an average of 10 per cent of the needles infested. 16 needles per shoot and 11 shoots per tree were damaged. About 94 per cent of the trees in the plantation were infested. The mass of green needles consumed per year and hectare was 2.2 kg with a total leaf area of 12.1 square meters. The loss of growth was calculated as 0.0018 fm of wood per hectare, which is of no account in healthy cultures but not in those which are simultaneously infested by other pests reducing the photosynthetic capacity of the pine.