Popis: |
The development, body weight, survivorship, and reproduction of the cotton bollworm, Helicoverpa armigera (Hubner), were evaluated in the laboratory at 27°C and photoperiod L:D = 14:10 on six host plants: cotton (Gossypium hirsutum L.), corn (Zea mays L.), tomato (Lycopersicon esculentum Mill), hot pepper (Capsicun frutescens L.), tobacco (Nicotiana tobacum L.), and common bean (Phaseolus vulgaris L.). Cotton bollworm larvae successfully survived on all six host plants, although mortality was very high on hot pepper and tomato. The developmental time of immature stages ranged from 26.6 d on corn to 35.1 d on tomato. Body weight of young fourth instar larvae ranged from 22.8 mg on corn to 5.9 mg on tobacco, while body weight of young last instar larvae and pupae ranged from 176.7 mg on cotton to 132.5 mg on tomato, and 285.2 mg on corn to 167.1 mg on tomato, respectively. Immature survival from egg to pupa varied from 33.1% on cotton to 1.7% on hot pepper. The average number of eggs oviposited by adults reared on cotton, corn, common bean, tomato, hot pepper, and tobacco were 708.4, 784.8, 778.1, 559.1, 562.5, and 314.3, respectively. The net reproductive rate of this species, measured from egg to egg, varied from 117.6 on cotton to 5.1 on hot pepper. We conclude that H. armigera can complete their life cycle on all six host plants, although tomato and hot pepper were relatively unsuitable. |