Stable isotope markers have been used to study animal nutrition for several decades and more recently to study the foraging
and cultural habits of imported fire ants. In this work, we have extended that effort to evaluate the potential for marking
boll weevils, Anthonomus grandis grandis Boheman (Coleoptera: Curculionidae), with the rare earth element samarium to aid in studies of insect invasion and pest eradication protocols. Neutron activation
analysis (NAA) was performed on the marked boll weevils as well as plant material from the cotton squares on which the insects
were fed. Samarium levels in non-dosed insects average about 20 ng/g or about 100 pg total element per insect. Our computed
average determination limit was 36 pg samarium/weevil. The determination limit for cotton plant squares and leaves averaged
3.5 ng/g and 8.2 ng/g, respectively. These initial results indicate the NAA method is capable of identifying individual marked
insects which have assimilated 1 ng of samarium, a ten-fold increase in content over average blank values.