OVIPOSITIONAL RESPONSE OF TOBACCO BUDWORM MOTHS (LEPIDOPTERA, NOCTUIDAE) TO CUTICULAR LABDANES AND SUCROSE ESTERS FROM THE GREEN LEAVES OF NICOTIANA-GLUTINOSA L (SOLANACEAE)

Field plots of three accessions of Nicotiana glutinosa L. (Nicotiana species accessions 24. 24A, and 24B) at Oxford, North Carolina and Tifton, Georgia were heavily damaged by natural populations of tobacco budworms, Heliothis virescens (F.), during 1985-1989. Experiments in outdoor screen cages demonstrated that all accessions of N. glutinosa were as prone to oviposition by H. virescens moths as was NC 2326, a commercial cultivar of flue-cured tobacco, N. tabacum L. However, in greenhouse experiments, tobacco budworm larvae did not survive or grow as well when placed on plants of N. glutinosa as they did when placed on plants of NC 2326. Four labdane diterpenes (manool, 2-hydroxymanool, a mixture of sclareols, and labda-13-ene-8-alpha, 15-diol [labdenediol]) and two sucrose ester fractions (2,3,4-tri-O-acyl-3'-O-acetyl-sucrose [G-SE-I] and 2,3,4,-tri-O-acyl-sucrose [G-SE-II]) were isolated from green leaves of the three accessions of N. glutinosa. These components were bioassayed for their effects on the ovipositional behavior of tobacco budworm moths using small screen cages in a greenhouse at Oxford, North Carolina. Labdenediol, manool, and both sucrose ester fractions stimulated tobacco budworm moths to oviposit on a tobacco budworm-resistant Tobacco Introduction, TI 1112 (PI 124166), when these materials were sprayed onto a leaf.