none Several factors that may affect oviposition by Microplitis croceipes (Cresson) in an artificial oviposition substrate were investigated. Significantly fewer females oviposited in thin disks of agarose gel than in hemispheres, cylinders, or cubes, although there were no differences in numbers of eggs laid. A higher percentage of females that had oviposited in a Heliothis zea (Boddie) larva before testing oviposited in an artificial substrate than did females without oviposition experience. In addition, experienced females laid more eggs than inexperienced females. When the artificial substrate was colored with red, yellow, blue, or green food colored substrates elicited more ovipositions than did uncolored substrates, and the number of eggs laid was highest for the blue substrate. The mean number of eggs laid increased also with the food color concentration. The total number of eggs laid increased with the number of substrates per Petri dish.