Artificial selection of a predatory species and the use of semiochemicals have been studied to enhance the performance of natural enemies. In the first study, three trials of artificial selection were conducted to enhance the survival of a Coleomegilla maculata from Iowa on Leptinotarsa decemlineata eggs. No oviposition was observed by these females when fed L. decemlineata eggs for sixty days. In the third trial, C. maculata first instars were fed on punctured L. decemlineata eggs and A. pisum. Adults were mated and oviposition by C. maculata was obtained only on L. decemlineata eggs and Acyrthosiphon pisum. Fifty-two percent of C. maculata survived to adult stage in the first generation, and 46% survived to the adult stage in the second generation. The time of larval transfer (> 24 hr after eclosion) may be an important factor to enhance survival of C. maculata larvae on L. decemlineata. First instar C. maculata that feed on the chorion of unhatched and hatched eggs may increase body size and successfully feed on L. decemlineata eggs. The second study in this thesis evaluated whether the attractant 2-phenylethanol, available commercially as the product Benallure[trademark symbol], can enhance the predation rate of predatory insects on L. decemlineata eggs and Ostrinia nubilalis egg masses in either corn or potato plants, respectively. In summer 2001, Benallure[trademark symbol] (2-phenylethanol) was tested as an attractant to enhance predation of L. decemlineata eggs by predatory insects on potato plants. The type of damage was characterized as damage due to either piercing-sucking or chewing predators. There was a tendency for higher L. decemlineata egg masses damage in lure treated plots compared to untreated plots. In summer 2002, a second experiment was conduced to determine if 2-phenylethanol could enhance the predation of O. nubilalis egg masses by predatory insects. 2-phenylethanol was placed in the middle of experimental plots and O. nubilalis egg mortality was monitored. The total O. nubilalis egg masses predation was 34% in lure treated plot compared to 28% in control plot. The attraction of the natural enemy, C. maculata and Chrysopidae species, with 2-phenylethanol enhanced the level of egg mass predation of L. decemlineata and O. nubilalis. More research is needed to better understand the interaction of 2-phenylethanol with biotic factors as pollen or alternative food sources for the prey.