Nesting interactions of the social wasp Dolichovespula saxonica [F.] (Hymenoptera: Vespinae) in wooden nest boxes for birds in the forest reserve „Las Piwnicki” in the Chełmno Land (Northern Poland)

The aim of this research was to investigate the process of colonization in wooden nest boxes for birds by the wasp Dolichovespula saxonica [F.] in the forest reserve “Las Piwnicki” during 1986-1987. About 69% of 150 nest boxes were colonized (36% by D. saxonica) in 1986 and 35% (10% by D. saxonica) in 1987. Parasite Shecophaga vesparum Court was observed inside small cell nests (SC) and large cell nests (LC) in the ratio of 5(SC) : 3(LC). During the two seasons, the decrease in the number of parasited nests followed with the ratio of 10(1986) : 1(1987). Competition of the „wasp - wasp” type (VV) compared to other competition types, such as „wasp - bird” (VA) and different types with wasps (DT), was the most frequent one among the interactions and followed with the ratio 1(VV) : 7(VA) : 5(DT). The number and proportions of construction types of nests during the studied growing seasons seem to prove the regular and irregular development of the Dolichovespula saxonica colony.