Techniques for Rearing Laboratory Colonies of Tobacco Hornworms and Pink Bollworms1

Larval tobacco hornworms, Manduca sexta (L.), were individually reared in polystyrene containers on an artificial diet. The developmental period (egg to adult) was completed in ca. 40 days at 26° C, which allowed production of 9 generations/year. Weights of the 5th stage larvae and pupae ranged from 7.5-9 g and 4.0-5.5 g, respectively. Survival of the immature stages ranged from 94-97%. Cage populations of 50-70 pairs of adults yielded 5000+ eggs/day when night temperatures were maintained at 26-28°C. From 1000-5000 hornworms were produced each week at an estimated cost (excluding labor and overhead) of ca. 30/1000. Colonies of the pink bollworm, Pectinophora gossypiella (Saunders), were also reared on the tobacco hornworm diet. The larvae were reared individually in polystyrene vials covered with polyethylene caps which prevented excessive drying of the larval diet even at low room humidities of 20-30%. Performance of the colony was as good as that of pink bollworms reared on other diets, and microbiol contamination was rarely encountered.