ABSTRACT
Techniques for detecting maternal trace element labels (Rb, Sr, Cs) in individual eggs of cotton bollworm (CBW), Heliothis zea, and tobacco budworm (TBW), H. virescens, were developed. Eggs from adults reared in field cages on treated host plants were analyzed by atomic absorption spectrophotometry. Incorporation of Rb in the eggs of both Heliothis spp. was achieved; neither Sr nor Cs was found above the 50% level. The presence of Rb was nearly 100% detectable in the eggs of CBW reared on treated corn, and detectable quantities of Rb were found in 95% of the eggs of TBW reared on treated pigeon pea. Failure to detect marks in eggs from other hosts, cotton and sorghum, was most likely a function of inaccurate timing of element applications relative to the fruiting stage of the hosts. The use of this marking method in a field experiment program to follow dispersal of eggs has been proposed.
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