TABLE 2.

LD₅₀ determination^a

Stachylysin injected (μg/100 μl)	No. of worms injected	No. of worms surviving
24	6	0
6	6	2
1.5	6	5
0	6	6

^aThe LD₅₀ was determined by injecting into each worm (3.5 ± 0.5 g) 100μl of purified stachylysin diluted in sterile water to 24, 6, 1.5, and 0 μg. The earthworms were maintained at 23°C, and their health was noted at 72 h. The estimated LD₅₀ for L. terrestis is 1.1 μg/g of worm based on a logistic regression of log₁₀ dose of stachylysin versus survival.