HELIOTHIS VIRESCENS AND H. ZEA (LEPIDOPTERA: NOCTUIDAE) FEASIBILITY OF USING OIL-SOLUBLE DYE TO MARK POPULATIONS DEVELOPING ON EARLY-SEASON HOST PLANTS1,2

Abstract

A greenhouse test and two field tests were conducted to determine if a dye method of marking the fat body using Red Calco Dye could be used to identify adult tobacco budworms, Heliothis virescens (F.), and the bollworms, H. zea (Boddie), that had developed as larvae primarily on Geranium dissectum L. In a greenhouse trial, 73% of 22 adult tobacco budworms contained internal red dye after larvae fed on geranium plants treated with 10 ml of a dye mixture per plant (1% dye + 9% crude cottonseed oil + 90% water). No dye was detected in adults from larvae reared on untreated plants. One field was first infested with neonate tobacco budworms, and then treated with the dye mixture. Marked adults were caught in blacklight traps over a 13-day period. A second field of wild geranium, being ca. 11% of the total geranium in the immediate area, was treated with the dye mixture without artificial infestation. From the first to last marked adult caught in pheromone traps, 6.8% of the bollworms and 8.3% of the tobacco budworms contained internal red dye.