Studies on population frequency of insects and mites causing galls on the leaves of the European aspen Populus tremula L. in southern Poland

Abstract

Species composition of galls on the leaves of Populus tremula L. was studied in 2002–2003 in two localities: the Ojcow National Park and the Andrychow Forest District. A total of 2,199 galls were found, 1,522 of which were found in 2003. The galls were caused by ten insect or mite species. The species composition of the galls was similar in these two consecutive years. Phyllocoptes populi (Nalepa) was the most abundant species in both areas in 2003. The index of occurrence frequency (F) value was highest in the case of P. populi, namely 0.280 in the Ojcow NP (2003), and lowest , i.e. 0.00002, for Trichiocampus grandis (Lepeletier) at both sites in 2003, and for Contarinia petioli (Kieffer) in the Ojcow National Park in 2002. The highest value for Agrell’s index of species co-occurrence , i.e. 0.944, was found for Harmandia cavernosa (Rubsaamen) and H. tremulae (Winnertz) (Ojcow NP, 2002), and the lowest (0.050) for T. grandis and H. globuli (Rubsaamen) (Ojcow NP, 2003).