Author
Jackson, D | |
NOTTINGHAM, S - ARS-ATHENS, GA | |
SCHLOTZHAUER, W - ARS-ATHENS, GA | |
Horvat, Robert | |
SISSON, V - N. C. STATE UNIVERSITY | |
Stephenson, Michael | |
FOARD, T - UNIVERSITY OF GEORGIA | |
MCPHERSON, R - UNIV. OF GEORGIA-TIFTON |
Submitted to: Environmental Entomology
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 7/3/1996 Publication Date: N/A Citation: N/A Interpretive Summary: Cardiochiles nigriceps, a parasitic wasp that helps control tobacco budworm larvae on several crops, was monitored in fields with up to 117 types of wild tobacco (Nicotiana species) during 1985-1994 in NC and GA. We found an average of 60 times as many wasps on N. noctiflora and 19 times as many wasps on N. sanderae as were found on commercial tobacco, even though N. noctiflora and N. sanderae are poor host plants for tobacco budworm larvae. C. nigriceps adults were associated primarily with the flowers of several species, but they were found equally on the leaves and flowers of N. noctiflora. Male wasps predominated in plots of many wild tobacco species, but female wasps predominated in cultivated tobacco fields. C. nigriceps adults appeared to be attracted to volatile components from N. noctiflora leaves and flowers. Technical Abstract: Cardiochiles nigriceps Viereck, a nearly obligatory parasitoid of tobacco budworm larvae, Heliothis virescens (F.), was monitored in fields with up to 117 accessions of 64 Nicotiana species (Solanaceae) during 1985-1994 in NC and GA. Over 10 years, an average of 60 times as many C. nigriceps adults were counted on N. noctiflora Hooker and 19 times as many wasps were ecounted on N. sanderae Hort. ex Watson as were found on commercial tobacco N. tabacum L. cv. NC 2326, even though N. noctiflora and N. sanderae are poor host plants for tobacco budworm larvae. Male wasps predominated in plots of N. alata Link & Otto, N. noctiflora, and N. sanderae; whereas, female wasps predominated in tobacco fields. There were no significant differences in the sex ratios of wasps from N. alata or N. sanderae. C. nigriceps adults were associated primarily with the flowers of N. sanderae, N. alata, and N. forgetiana Hort ex Hemsley, but they were found equally on nthe leaves and flowers of N. noctiflora. C. nigriceps adults appeared to be attracted to volatile components from N. noctiflora leaves and flowers. Gas chromatography of volatiles from extracts of N. noctiflora leaves and flowers showed only four volatile peaks, which were identified as nitrogen-sulfur heterocycles. |