Ref ID : 6032
S.A. Viljoen and A.J. Reinecke; The temperature requirements of the epigeic earthworm species Eudrilus eugeniae (Oligochaeta) - A laboratory study. Soil Biol.Biochem. 24(12):1345-1350, 1992
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Juvenile specimens of the epigeic earthworm species, Eudrilus eugeniae were subjected to a range of different constant temperatures in a temperature gradient trough over a period of 80 days. Other environmental factors and food availability were maintained at a constant, optimal level. Survival, growth rate, maturation and cocoon production were monitored regularly. No worms survived at temperatures <12 degrees C and all succumbed after 50 days at temperatures of 30 degrees C and above. A steady increase in growth rate was observed with higher temperatures and the highest mean biomass per worm was attained at 29 degrees C. The highest maturation rate was obtained at 22 and 25 degrees C was found to be the optimal temperature for cocoon production. The results indicate that this earthworm species is very sensitive to low temperatures and can survive temperatures up to 30 degrees C. It was also noted that although higher temperatures favoured growth, fecundity would be higher at temperatures ranging from 22 to 25 degrees C. It is concluded that this earthworm species would be a better candidate for vermiculture in regions with a tropical or moderate climate as it exhibited a fairly narrow tolerance range for temperature with a high degree of intolerance for temperatures below 16 degrees C.