A comparison of mustard, household detergent and formalin as vermifuges for earthworm sampling

The efficiencies of three vermifuges (household detergent, mustard and formalin) in extracting earthworms were compared in a pasture in western Norway. Relative efficiency of detergent and mustard compared to formalin with respect to number of earthworms extracted, was 79% and 66%, respectively. No significant differences were found among the three treatments in proportion of juveniles, earthworm size, number of earthworms or biovolume of emerging earthworms. Two genera of earthworms were represented in the samples, Allolobophora spp. and Lumbricus spp. Genus composition differed among the three treatments, formalin extracting the highest percentage of Allolobophora spp. and mustard the lowest. The relative efficiency of the three vermifuges differed from what has been found in an earlier comparable study. Both mustard and household detergent are less detrimental to health of vegetation, earthworms and field workers than formalin, and given their relatively high efficiency as vermifuges, they might in many cases be preferable to formalin.