Doane (1962) tested the effects of DDT on Lumbricus terrestris 
and Allolobophora caliginosa. He applied DDT at 2.8 and 25 1b/A to plots 
20 feet square, using four replications, Granular formulations and water 
emulsions were used on light sandy soil on May 19 and June 23, 1960. 
Both worm species were easily collected for toxicant analyses that 
October. However, in October of the next year, cast counts indicated 
significantly reduced earthworm populations on those plots treated at 
25 1b/A. Populations appeared unaltered on plots treated at 2.8 1b/A. 
Avoidance reactions by the earthworms were not precluded as a reason 
for the observations. 
Dieldrin 
In one phase of his tests, Schread (1952) obtained good worm 
control with dieldrin applied at 44 1b/A. A 60-square-foot plot of golf- 
green grass in a nursery was treated with dieldrin "emulsion" in June. 
The treatment was watered in and soaked again after 24 and 48 hours. 
Worms were well controlled by August, and there had been no reinfestation 
a year later, Untreated plots remained heavily infested. 
Polivka (1953) treated field plots on an Ohio golf course in 
two experiments. Plots treated in March with 1, 5, 10, 20, 40, and 80 1b/A 
of dieldrin contained significantly fewer earthworms in late September 
than did untreated plots. In the second experiment, plots treated with 
dieldrin at 1, 5, 10, 15, 20, and 25 1b/A showed no significant differences 
in earthworm populations after 6 weeks. 
Hopkins and Kirk (1957) reported that Eisenia foetida survived 
treatments of dieldrin at 5 1b/A for 2 months. In a second experiment, 
the worms were exposed for 4 days to media composed of dieldrin dust mixed 
with soil at rates of 32, 64, 128, and 256 1b/A of dieldrin. The LDsq at 
96 hours was computed at 183.2 1lb/6-in A. 
Luckmann and Decker (1960), studying. Illinois fields treated 
with 2 and 3 1b/A of dieldrin, found no differences in the number of 
earthworms between treated and untreated plots. Samples of soil 1 foot 
Square and 9 inches deep were taken in both areas, 1 and 4 years after 
treatment, in both corn and soybean crops. The soil was a sandy loam. 
Dieldrin spray at 10 1b/A eliminated cast production by 
Lumbricus terrestris and Allolobophora caliginosa 18 months after applica- 
tion to a light sandy soil (Doane 1962). Casts were present, but signifi- 
cantly reduced in numbers, where 10 1b/A of dieldrin granules was used. 
IL 
