Date of Award:

5-1-1968

Document Type:

Dissertation

Degree Name:

Doctor of Philosophy (PhD)

Department:

Biology

Department name when degree awarded

Entomology

Committee Chair(s)

W. A. Brindley

Committee

W. A. Brindley

Committee

G. E. Bohart

Committee

D. W. Davis

Committee

L. C. Ellis

Abstract

Technical parathion, 98.5 per cent pure, was further purified by column chromatography in a darkened room. The purity of this parathion was measured by a manometric technique (Nakatsugawa and Dahm, 1962; 1965). Only 5 per cent inhibition at 2.5 x 10-5 molar parathion was observed with horse serum cholinesterase. Alkali bee prepupae were dug from their natural sites, and reared under the laboratory conditions until they emerged. The bees were kept in one quart mason jars, and they were fed a 25 per cent aqueous sucrose solution. All biological assays were conducted by topical application of 1 microliter of purified parathion in glass distilled acetone solution to the dorsal portion of the thorax with a microapplicator. Insects used as controls for LD50 and age-parathion response were similarly treated with 1 microliter of glass distilled acetone. The LD50 data were analyzed by probit analysis. To find the relation between age and response to parathion, the bees were fed on 25 per cent sucrose solution for 1, 4, 7, and 10 days after emergence. One microliter of 2.58 x 10-4 molar parathion was applied to each bee and the results were analyzed by a chi-square test. Chlorcyclizine dihydrochloride and SKF 525-A hydrochloride were fed to the bees at a concentration of 0.1 per cent in aqueous sucrose solution. The bees were fed for four days after emergence on various feeding sequences and at the end of the fourth day 1 microliter of 2. 5 x 10-4 molar parathion in acetone solution was applied to each bee. The data were analyzed by a chi-square test. The analysis of variance of dosage-mortality data indicated a highly significant regression between the doses of parathion applied and the response of the bees. The LD50 values, 24 hours after treatment, formales were 0.0862 microgram per bee and for females were 0. 0926 microgram per bee. The bees showed a higher sensitivity to parathion as they aged. The difference in mortality between one and four days after emergence was not highly significant. But the difference between males four and seven days after emergence and between bees of both sexes of seven and ten days after emergence was highly significant. Chlorcyclizine enhanced the toxicity of parathion to alkali bees. It seemed to persist in its effect for at least two days and did not need to be maintained in the diet. Chlorcyclizine could be given on alternate days without losing its effectiveness. SKF 525-A showed rather variable results. When it was given to the bees before and after application it increased the toxicity. When it was given to the bees only before parathion application it had a negligible effect on mortality

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