Effect of Calco Oil Red N-1700 Dye Incorporated into a Semiartificial Diet of the Imported Cabbageworm, Corn Earworm, and Cabbage Looper124

When Calco Oil Red N-1700® dye was added to the artificial larval diet of Pieris rapae (L.), Heliothis zea (Boddie), and Trichoplusia ni (Hübner), some of the internal organs of the adults, and the eggs deposited, were dyed pink. The male pupal weight of P. rapae, male and female pupal weight of T. ni, and longevity of H. zea were significantly less (P = 0.05) than for those reared on diet that did not contain dye. Also, the peak of the oviposition period occurred 1 day later for P. rapae females reared on diet containing dye, and both H. zea and T. ni were observed to deposit fewer eggs. None of these differences, however, are considered sufficient to prevent effective use of the dye for marking released specimens for field studies.