Nigriceps

Behavioral and chemical evidence for signal specificity was also obtained by De Moraes et al. (1998). They found that Cardiochiles nigriceps, a parasitoid that specializes on Heliothis virescens, is much more attracted to plants attacked by its host than by plants attacked by the closely related non-host H. zea. Volatile collections... 

C. nigriceps could distinguish between the odor of plants that have been damaged by its specihc host H. virescens and the odor of plants damaged by a closely related non-host. In a natural, non-agricultural environment, Kessler and Baldwin (2001) supplemented the odor of wild tobacco plants with synthetic volatiles and found that (Z)-3-hexenol, linalool and (Z)-a-bergamotene all increased the predation rate... 

Syvertson, T.C., Jackson, L.L., Blomquist, G. J. and Vinson, S. B. (1995). Alkadienes mediating courtship in the parasitoid Cardiochiles nigriceps (Hymenoptera Braconidae). J. Chem. Ecol., 12,1971-1989. 

Hydrocarbons with methyl branching at C-ll to C-13 were isolated from Heliothis virescens (Noctuidae, Lepidoptera) 229). These compounds release a host-seeking behavior in the braconid Cardiochiles nigriceps, a Heliothis parasit. These kairomones were prepared in 1975 by Vinson et al. 229) by Wittig methylenation of the corresponding methyl ketones and subsequent catalytic hydrogenation 229). 

Isomeric cis-verbenol is an aggregation pheromone attractant for both the male and female insects of the species. The same author [105] published information concerning a defense secretion of the soldiers of the termites Nasutitermes nigriceps, N. Ephratae and Velocitermes velox from Peru). The enantiomeric compositions of a -pinene and limonene produced by three termite species are as follows ... 

Reports of the secretory nature of the calyx region date back over twenty years. Salt (44) recognized that secretions of the calyx of the ichneumonid Venturia (= Nemeritis) canescens affected the host immune system. Studies on the ichneumonid . sonorensis revealed the presence of nuclear secretory particles associated with the calyx cells (96). Those studies were followed by the confirmation of DNA in virus particles associated with the oocytes of the braconid C. nigriceps (97). 

Four species of Nasutitermes soldiers, N, columbicus, corniger, eph-rates and nigriceps from Costa Rica and Panama, can be distinguished by means of their chemical defense secretions 543), The authors of the study suggested that climate had an influence on the chemical composition of secretions from two Pacific Coast populations of N, corniger and postulated that the Atlantic Coast population of the species derived from a Pacific Coast population. 

Vinson, S.B., R.L. Jones, P.E. Sonnet, B.A. Bierl, and M. Beroza Isolation, Identification and Synthesis of Host-Seeking Stimulants for Cardiochiles nigriceps, a Parasitoid of Tobacco Budworm. Entomol. Exp. Appl. 18, 443-450 (1975). 

Larval parasitoids respond to silk, frass, volatiles, cuticular components, and glandular secretions (Weseloh, 1981). For example, Cardiochiles nigriceps responds to hydrocarbons in the mandibular glands of H. virescens (Vinson, 1968), Apanteles melanoscelus responds to the silk produced in labial glands of gypsy moth (Weseloh, 1977), and several species respond to host feces. 

The role that chemicals play in host preference has received little attention. Contamination of an unacceptable host by the odor of a preferred host may result in the attack of the unacceptable host (Spradberry, 1968). Cardrochiles nigriceps, for example, readily attacks and accepts Galleria mellonella and... 

The ability to discriminate also appears to be influenced by experience (van Lenteren, 1976). As shown by van Lenteren (1976), inexperienced females may superparasitize many hosts until they encounter unparasitized hosts and learn to discriminate. It also appears that location of the host may be a matter of experience. Female Cardiochiles nigriceps are more likely to search for and attack hosts if they have previously encountered a host than inexperienced females (Strand and Vinson, 1982a). 

---