Submitted to: Journal of Insect Physiology
Publication Type: Peer reviewed journal
Publication Acceptance Date: 4/13/2006
Publication Date: 4/28/2006
Citation: Popham, H.J., Shelby, K. 2006. Uptake of dietary micronutrients from artificial diets by larval heliothis virescens. Journal of Insect Physiology. Available at http://dx.doi.org/10.1016/j.jinsphys.2006.04.005. Interpretive Summary: Laboratory insects are reared in the laboratory on an artificial diet that is formulated to imitate the nutrients they receive often from plants in the field. Many of the components of insect diets have been studied previously and the optimal level for different insects is known. However, very little is known about the optimal level of micronutrients such as zinc and chromium in insect diets. In this study, the levels of 10 micronutrients in insects were measured and compared to the amount in the insect diet. Four of the micronutrients were identified as critical in relation to the amount found in the diet. Optimizing the insect diet will allow laboratory reared insects to be more comparable to field insects, meaning that data collected on studies of laboratory insects will more closely match data collected in field situations. Overall, this will help scientists interpret laboratory data correctly and allow correct extrapolation of control measures to the field.
Technical Abstract: Larvae of Heliothis virescens were fed different levels of Se. The Se content of pupae and plugs of artificial diet was analyzed by inductively coupled plasma-mass spectrometry (ICP-MS) as were the levels of ten other metals. Chromium, cobalt, iron, magnesium, manganese, nickel, selenium, sodium, and zinc were all found to persist at constant levels regardless of the amount of selenium added to the diet. Only copper and molybdenum were found to change significantly in relation to the amount of added Se. Larvae fed zinc, which was found in higher levels in pupae than diet, had a deleterious response to increasing levels of zinc. Larvae fed chromium, found in higher levels in diet than in pupae, were not adversely affected when increasing levels of chromium were added to the diet. Based on this analysis, metals were identified that might well impact the fitness of a given colony of insects in relation to their diet.