The biology and population dynamics of Eudrilus eugeniae (Kinberg) (Oligochaeta) in cattle waste solids

The growth and reproduction of Eudrilus eugeniae (Kinberg) in cattle waste solids was studied by growing groups of 1, 2, 4, 8 or 16 small earthworms in 100 g of waste in small containers in incubators at 15 degrees, 20 degrees, 25 degrees and 30 degreesC. Earthworms were weighed weekly and the numbers of cocoons produced per week assessed. Fecundity, growth, maturation and biomass production were all significantly greater at 25 degreesC than 15 degrees, 20 degrees or 30 degrees. The growth of individual earthworms increased the lower the population density, but the greatest overall earthworm biomass production occurred at the highest population density. The highest ratio of conversion from organic waste to earthworm biomass (dry weight) was 10: 1, Cocoon production, the times for cocoons to hatch, the percentage hatch and the number of earthworms hatching per cocoon, at each temperature were recorded. The rates of growth of hatchlings at these temperatures was measured. The greatest number of coccons per week and the number of hat chlings per cocoon were obtained at 25 degreesC. Cocoons of E. eugeniae hatched in only 12 days at 25 degreesC, the earthworms at these temperatures reached sexual maturity in as little as 35 days after hatching and gained weight at maximum rate of 280 mg per week.