Originally presented as the author's thesis, Wageningen. / Includes bibliographical references (p. 171-176).

A method of bioassay distinguishing residual contact from fumigant toxicity is described. Basically the apparatus consists of a series of Buchner funnels set up in series. Woven fiberglass cloth was selected as the substratum. By substitution of a dye in place of Insecticide, it was possible, using colorlmetric analysis, to calculate the total milligrams of dye adhering to the cloth. It was assumed that proportionate amounts of dye and insecticide would be picked up. Musea domestica L.was used as the test insect. Two strains of flies, designated as the SES and Ottawa cultures, were used. Fumigant effect was eliminated by application of negative pressure. Since fumigant effect is proportionate to vapour pressure, the rate of evacuation varied for each insecticide. Elimination of fumigant effect brought about a corresponding decrease in mortality. Dosage-mortality data are given for six insecticides in comparison to a "standard" insecticide (dieldrin) utilizing the concept of toxicity index ( Sun, 1950). Statistical analysis of the data indicate significant heterogeneity in eleven out of twenty-four experiments. An analysis of the Chi-square function is presented. Dosage-mortality data for DDT are given. The SES culture was determined to be 141x as resistant for females and 67x as resistant for males as the Ottawa culture, by topical application. Residual contact application indicated that females of the SES culture were 252x as resistant compared to the Ottawa culture. Variation within the SES culture is discussed as a factor in demonstrating the sensitivity of the technique. / Science, Faculty of / Zoology, Department of / Graduate

Soil was treated with Aldrin, Isodrin, Dieldrin and Endrin respectively and a number of horticultural crop plants planted in it and the effects were observed and recorded. Yield increases were obtained with potatoes and carrots under field conditions, the maximum yield being found at the rate of 6.5 lbs. per acre of each compound used. Growth rates of tomato plants appeared to be slightly stimulated by all the compounds. With radish, on the other hand, Aldrin and Isodrin depressed foiliar growth while Dieldrin and Endrin favoured top growth; this was reflected in top-root ratios. Dieldrin and Endrin had a definite stimulatory effect on germination of radish seeds grown on treated agar. Maximum stimulation was obtained with Dieldrin and Endrin at 40-200 p.p.m., with Isodrin at 40 p.p.m. and Aldrin at 10 p.p.m. Soil applications of the compounds appeared only slightly to stimulate radish seed germination while tomato seeds were unaffected. A general depression of sugar content was noted in all crops with all compounds while Vitamin C content of radish was significantly depressed. Aldrin and Isodrin greatly depressed the nitrogen content of radish tops and roots while phosphorus was depressed greatly in the foliage. Dieldrin and Endrin increased nitrogen in radish foliage and roots and had little effect on the phosphorus content. Aldrin and Dieldrin greatly increased the chlorine content of potatoes but did not affect the dry matter content. Endrin and Isodrin had little effect on the chlorine content of carrots. / Land and Food Systems, Faculty of / Graduate

No description available.

Thesis (Ph. D.)--University of Wisconsin--Madison, 1969. / Typescript. Vita. Description based on print version record. Includes bibliographical references (leaves 236-265).

Thesis (Ph. D.)--University of Wisconsin--Madison, 1961. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 54-61).

Thesis (Ph. D.)--University of Wisconsin--Madison, 1962. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Thesis (Ph. D.)--University of Wisconsin--Madison, 1954. / Typescript. Vita. Includes reprints of various journal articles by the author et al. Includes bibliographical references (leaves 116-136).

Thesis (M.S.)--Montana State University--Bozeman, 2007. / Typescript. Chairperson, Graduate Committee: Robert K. D. Peterson. Includes bibliographical references (leaves 104-113).

No description available.