Rutin was demonstrated to be a phagostimulant for the grasshopper Schistocerca americana across a very wide concentration range. The effect was not maintained over a period of days if the insects had already ingested a large amount, but when individuals were given different concentrations on disks as supplements to their lettuce diet, they tended to self select a moderate quantity on a daily basis. In long term experiments on food utilization and growth rates using artificial diet, no beneficial effects of rutin could be demonstrated. Ingested rutin was absorbed and some of it deposited in the cuticle. Most was excreted as the aglycone quercetin. The possible functional significance of the phagostimulatory effect is discussed.

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Five human volunteers entered methyl parathion, ethyl parathion, or monocrotophos treated cotton fields for five-hr exposure periods when the residues of the respective pesticides had aged 12 hr, 24 and 48 hr and 72 hr. Foliage residues of methyl parathion disappeared fastest, those of monocrotophos slowest. Personal exposure to pesticide was evaluated from contamination of skin, clothing, and ambient air, while actual absorption of chemical was assessed from pesticide concentration in blood, urinary metabolite excretion, and effects on blood cholinesterase activities. There was good correspondence between magnitudes of foliar residue, estimates of personal contamination, and measures of chemical absorption. Field exposures caused no symptoms or clinical signs of organophosphate poisoning and depressed averaged blood cholinesterase activities by no more than 14% of pre-exposure levels.