Das Eiablageverhalten des Nierenfleckzipfelfalters Thecla betulae (Lepidoptera, Lycaenidae) in Südwestdeutschland

To investigate the oviposition preference of the brown hairstreak butterfly (Thecla betulae), the host plant, blackthorn (Prunus spinosa) and the eggs of Thecla betulae in the area around Tübingen (Baden-Württemberg, Germany) were mapped and various parameters recorded and analyzed. A total of 2972 blackthorn bushes were surveyed and a total of 576 eggs were found on 311 (10,5 %) of them. In most cases only one egg was found on a branch, but in 24 cases 2 or 3 eggs were found. The study clearly shows that Thecla betulae prefers young Prunus spinosa bushes up to 3 meters height. Small plants up to 1.5 meters high are particularly favoured. Interestingly, Prunus spinosa in urban areas were used as oviposition sites significantly more often than those in the countryside around Tübingen, presumably due to the slightly warmer microclimate in towns. Prunus spinosa bushes facing south-, east- and particularly southeastwards were favoured for oviposition, while those facing northwards were rarely used.