EFFECT OF CORN SILK AGE ON FLAVONE CONTENT AND DEVELOPMENT OF CORN-EARWORM (LEPIDOPTERA, NOCTUIDAE) LARVAE

The effects of silk age from 'Stowell's Evergreen' and 'Zapalote Chico ' on maysin (a luteolin-C-glycoside flavone) and isomaysin content, an d on weight and developmental time of larvae and weight of pupae of co rn earworm, Helicoverpa sea (Boddie), were studied. Differences in H. zea biological parameter responses to silk diets of 3 ages (nonpollina ted, 2- and 5-d-old pollinated) were found between cultivars. Ten-d-ol d pollinated silks had no adverse effects on developmental parameters of corn earworm larvae. Flavone content decreased as the age of Zapalo te Chico silk increased, but its concentration in 10-d-old pollinated silks of Zapalote Chico and Stowell's Evergreen was similar. A signifi cant negative correlation was found between weight of corn earworm lar vae and the amount of (milligram) maysin, isomaysin, or maysin plus is omaysin per gram of oven-dried silk of all silk ages.