Both larvae and teratocytes liberated upon hatching from the eggs of the endoparasitoid Cardiochiles nigriceps Viereck were found to release proteins into their surrounding environment as they develop. Teratocytes were found to synthesize and release a number of proteins into culture media in which they were incubated. The proteins released differed among the different teratocyte ages. Larvae were also found to release proteins into the culture media in which they were incubated. Ligation of the head or anal vesicle altered the protein pattern found in the media. The results demonstrate that both larvae and the associated teratocytes release proteins that may have important functions in the parasitoidhost interaction. 0 1994 ~i~e y -~i s s ,
Inc.Key words: parasitoid, protein secretions, teratocytes, parasitoid larvae
INTRODUCTIONInsects, following parasitism by parasitoid Hymenoptera, are either paralyzed or, if they grow and develop, the growth and developmental patterns are often altered. These pathologies, as discussed by Doutt [ 11, are not solely due to the physiological response of the host to the invader, but as discussed by Vinson and Iwantsch [2], are often due to factors released by the parasitoid that alter the physiology of the host in specific ways. Thus, the suitability of an insect to serve as a host for a particular parasitoid depends on constraints that the host represents [3] and the ability of the parasitoid to alter the physiological environment that the host represents. In some situations, and for some host processes, the developing parasitoid must conform to the physiological conditions of the host [4]. In other cases or for other processes in the same host, the parasitoid has evolved mechanisms that alter the host's immediate physiological environment [5-81. Acknowledgments: Approved as TA 30750 by the Director of the Texas Agricultural Experiment Station. Appreciation is extended to Zac Shawhan for insect colony maintenance.Received February 4, 1993; accepted April 6, 1993. 0 1994 Wiley-Liss, Inc.
198Vinson et al.Alteration of the physiological environment within which the parasitoid must develop involves both the injection and release of factors into the host [31. There are two basic sources of these factors. The first group is the parental derived factors that include the poison gland [9-111, calyx region of the lateral oviducts [12,13], the epithelium of the common oviduct [14], or the follicular epithelium [15,161. The second group is the progeny derived factors that include teratocytes and larvae that hatch from the egg [3]. Teratocytes are cells of the embryonic membrane of the parasitoid egg that are released upon hatching into the hemocoel of the host. The developing larvae are also a possible source of host regulatory factors.The larvae of Pimpla turionellae L. and ltoplectis conquisitor Say discharge secretions from their anus [24-271. These secretions have been reported to alter DOPA metabolism, and to have antibacterial and antifungal properties [24,27].Here we examin...
