Field and laboratory studies of the earthworm Dendrobaena Alpina

Abstract

Distribution of Dendrobaena alpina covers the mountainous region of central Europe, where it has a high dominance and frequency index. This work describes data from field studies conducted over two annual cycles in the Bieszczady National Park (BNP), Poland, in different types of beech forest. Densities of this species ranged from 47-231 · m-2 with associated biomasses of 19 – 90 g · m-2. Most (66 %) were recovered from less than 0.1 m soil depth with a further 28 % to 0.2 m. Further animals were collected alive from Lutowiska close to the BNP to obtain baseline data on the life history of D. alpina. Mature individuals were kept in isolation and cocoon production monitored on a 2 monthly basis. Immature individuals were kept until they reached maturity, when they were paired, with combined output of cocoons regularly monitored. Cocoons were collected, had masses determined and were incubated. Hatchability was recorded, as was estimated duration of incubation and growth to maturity. Field-collected adults had a mean mass of 1.4 g and at 15ºC, these produced an average of 1.83 cocoons worm-1 · month-1. Zero cocoons were produced by further specimens, collected as immature, grown to maturity and maintained in isolation. Recently-matured, paired D. alpina produced an average of 1.65 cocoons worm-1 · month-1. Cocoons had a mean mass of 19 mg. At 15ºC, cocoons produced by recently matured adults hatched after 80 days (82 % viable), but after 2 months the majority of cocoons failed to hatch. Hatchling growth from an average of 18 mg to maturity required 7-11 months in the given substrate.