Gedminas, A., Lynikienė, J., Marčiulynas, A. and Povilaitienė, A. 2015. Effect of Physokermes piceae Schrank. on Shoot and Needle Growth in Norway Spruce stands in Lithuania. Baltic Forestry 21(1): 162-169

In 2010, the spruce bud scale (Physokermes piceae Schrank.) infested 7,700 ha in Lithuania. The effect of the spruce bud scale damages like the reduction of shoot and needle growth in young spruce stands was studied in 2013. In order to determine the growth reduction in the shoots and needles, young (II-IV age class) spruce stands were examined. We have established 33 plots in stands in 9 different regions of Lithuania. Three branches from five trees were collected on each plot. The length (cm) of the shoots and the weight (g) of absolutely dried 100 needles were determined.

During the outbreak (2010), the shoot length and needle weight decreased almost twice (p < 0.05) in comparison with shoot and needle growth before the damage (2009). A direct negative effect of spruce bud scale was significantly (t ³2.91, p ≤ 0.05) higher in spruces growing in Western Lithuania (Jurbarkas, Kazlų Rūda and Šakiai) than in Central Lithuania (Kaišiadorys, Dubrava and Jonava).

Key words: needle weight, shoot length, spruce bud scale, spruce stands, Norway spruce, Picea abies