Pesticide residues in human milk and environmental samples from Kafr El-Zayat Governorate in Egypt were analyzed. This governorate is located near one of the biggest pesticide factories in Egypt. Organochlorine and organophosphorus pesticides were monitored, including those that have been prohibited from use in Egypt. Human milk samples (31 samples) from Kafr El-Zayat were compared with 11 samples collected from Cairo. Data were compared with results from studies performed in 1987 and 1990. The present study showed that aldrin and dieldrin, heptachlor and heptachlor epoxide, and endrin residues have been eliminated from human milk. Estimated daily intakes (EDIs) of DDT complex and gamma-HCH by breast-fed infants in Kafr El-Zayat were 85.96 and 3.1% of respective acceptable daily intakes (ADIs). beta-HCH residues showed an increasing pattern, especially in human milk samples from Cairo. DDT complex and HCH isomers in orange, spinach, lettuce, potatoes, and clover samples ranged from undetectable to very low concentrations. Higher levels of DDT and HCH were detected, but aldrin, dieldrin endrin, and the heptachlors were not detected in food of animal origin. Residues in fish samples were below maximum residue limits established by some developed countries. Those in animal milk samples approached the extraneous residue limits of the Codex Committee on Pesticide Residues. HCH residues in soil were negligible, but DDT residues in soil were somewhat higher. Among water samples, groundwater samples had the highest residues of HCHs and DDTs, followed by Nile River water and then tap water. However, the organochlorine pesticide residues were found at concentrations below the maximum allowable limits set by the World Health Organization for drinking water. Among 12 organophosphorus pesticides monitored as parent compounds, dimethoate, malathion, methamidophos, and chlorpyrifos residues were detected in low concentrations in soil samples from a pesticide factory. No organophosphorus pesticide residues were found in plant samples, except for very low residues of dimethoate in an orange sample. Water samples were devoid of organophosphorus residues as parent compounds.

It has been suggested that plants experiencing water deficits offer a higher quality source of nutrition to feeding insects. This hypothesis was investigated by assessing the performance of the cabbage aphid (Brevicoryne brassicae), an important pest on Crucifers, on the crop plant oilseed rape (Brassica napus). Aphid growth and reproduction was measured at three controlled air temperatures and four watering regimes to induce water deficits. Plant nutritional quality (soluble nitrogen) and microclimate (leaf temperature), both important for aphid growth and reproduction, were determined. With increasing water deficit both soluble nitrogen content (% dry weight) and leaf temperature (degree C) increased. At all three temperatures development time of the aphid to reproductive age was faster with increasing plant water deficits. Mean relative growth rates and the intrinsic rate of natural increase significantly increased with increasing water deficit at 15 degrees C and 20 degrees C, and 15 degrees , 20 degrees and 25 degrees C respectively. Air temperature, leaf temperature, and soluble nitrogen are important factors on aphid growth and reproduction. The results indicate that during periods of water deficit of oilseed rape plants, aspects of the growth and reproduction of B. brassicae are increased which may result in a faster rate of increase of aphid populations on this crop.

The effect of diet water content on the growth, cocoon quality and food utilization of the silkworm was investigated. The body weight of mature larvae increased greatly as the water content increased, and the weight increase was mainly due to the increase of water content of larvae. The diet water content was less effective on the water content of pupae than on that of mature larvae. The water content of feces increased progressively as the fifth-instar larvae grew, especially in the larvae fed with diets having high contents of water. The suitable water content in the diet ranged from 60 to 65% for the cocoon quality, although it was found to be somewhat different between the 2 silkworm races used. On the basis of the above results, we tried to make a new type of artificial diet for the silkworm