The preservation of host material in a state suitable for successful development of beneficial parasite or predator species is desirable for the mass culture of entomophagous species. Thus, Coppel and Mertins (1977) report the coddling of sawfly cocoons, and Fedde et al. (1979) chilled host eggs to keep them in a susceptible state for the egg parasite Telenomus alsophilae Viereck. Such techniques are also valuable to assure continuous rearing of parasites or predators during shortages of hosts.

The latter situation pertained while we were studying factitious hosts of the thelyotokous, multivoltine egg parasite Ooencyrtus ennomophagus Yoshimoto (1975). This parasite cannot develop in embryonated eggs; therefore it is essential to hold hosts in the unembryonated condition. Faced with the loss of the typical host for 0. ennomophagus, the univoltine elm spanworm, Ennomos subsignarius (Hübner), we found that eggs of the multivoltine pipla tentmaker, Clostera inclusa (Hübner), would suffice. Field populations of the tentmaker crashed in 1979, leaving us dependent upon a small field-cage rearing of this insect for experimentation.