Previous studies have shown, through periodic sampling, that more eggs of the polyphagous predator Coleomegilla maculata are found on certain plant species than others.  It has been unclear, however, whether these differences in C. maculata egg densities primarily reflect ovipositional preference for certain plant species or different rates of disappearance of eggs due to predation.  Our objective was to answer this question.  We used sweet corn plots because large numbers of adult C. maculata colonize this crop.  We first determined the diel periodicity of C. maculata oviposition in order to concentrate our efforts during the period of peak daily oviposition.  Beetles were then presented with two plant species: velvetleaf (Abutilon theophrasti), a species that possesses glandular trichomes, and smooth pigweed (Amaranthus hybridus), a species void of glandular trichomes.  Equal numbers of these plants were simultaneously observed in the field between noon and 7 P.M. EDT, and all observed ovipositions were recorded.  A total of 16 trials produced 30 observations of oviposition, all of which occurred on A. theophrasti.  Thus, previously reported observations of greater numbers of C. maculata eggs on A. theophrasti and other plants with glandular trichomes, compared to plants with few or no trichomes, appear to reflect a true ovipositional preference for plants with glandular trichomes.