Adults ofHeliothis virescens(F.) were provided untreated (0 ppm) or rubidium-treated artificial nectar (2,000 ppm rubidium chloride in 10% honey-water) for a 24-h period upon eclosion or 48 h after eclosion. All rubidium-treated females and>90% of the eggs from both rubidium treatment conditions contained reliably detectable levels of the maternal label. Significant differences were found in element content of eggs produced over the 10-d period, and some significant differences were found in the element content of eggs produced by different females within treatment groups per oviposition day. However, detectability of rubidium was not negatively affected.