Published online by Cambridge University Press: 10 July 2009
In experiments covering many successive generations of Musca domestica L. (strains NS and WHO/SRS/MHSCO domestica/1), sublethal doses of p,p'DDT applied topically to adults or fed to larvae or adults had no effect on the numbers of abnormal follicles, but the numbers of normal follicles increased in F1–3 when larvae were fed with diet containing 10 parts per million of DDT. These results conflict with those of previous workers. Other possible causes of abnormal oogenesis were examined. Sublethal doses of o,p'DDT and DDE (an impurity and metabolite, respectively of p,p'DDT) had no effect, whereas inbreeding and high-density rearing caused the numbers of normal follicles to fall; the latter caused the numbers of abnormal follicles to increase. There were also heritable differences in oogenesis among three strains of house-fly.