Toxic effect of lead on postembryonic development stages of Mamestra brassicae L.
1997
Weismann, L. (Slovak Academy of Sciences, Ivanka pri Dunaja (Slovakia). Inst. of Experimental Phytopathology and Entomology) | Rehakova, M.
Postembryonic development of Mamestra brassicae L. was investigated after intoxication of the 6th instar larvae per os by graded lead doses (34.35, 68.7, 137.4 and 274.8 micrograms Pb). The doses were reflected in morphological deformities of pupae and imagoes and in fertility reduction. The deformities increased with increasing doses. From the total amount of lead (229 micrograms) which the 6th instar ingested, 24 hours after moulting to pupation they had excreted 84.58 percent through faeces, while 14.94 percent were retained in the organism. Of this, 10.3 percent remained in the digestive tract. Into the pupae passed 9.26 percent of the total amount of lead ingested, that is, 63.7 percent of the lead retained in the organism. The distribution of lead retained in the larvae (33.3 micrograms) before pupation was as follows: 70.7 percent in the digestive tract, 8.9 percent in the haemolymph, 13.75 percent in body fat, and 6.58 percent in the integument. The lethal dose (LD sub(50)) for pupae was determined to be 19.5 micrograms Pb
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