The development, body weight, survivorship, and reproduction of the cotton bollworm, Helicoverpa armigera (Hubner), were evaluated in the laboratory at 27degreesC 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.

Summer diapause in the cotton bollworm, Helicoverpa armigera (Habner), is prolongation of the pupal stage, particularly in males, induced by high temperatures. The effects of exposing a parental generation to temperatures of 33 to 39degreesC on the development, survivorship, longevity and fecundity of their offspring were determined in the laboratory. Three groups of offspring were examined: A, the progeny of control female moths reared as larvae at 27degreesC mated to mate moths that had undergone summer diapause when exposed to high temperature; B, the progeny of control female moths mated to males that had not undergone summer diapause after exposure to high temperature; C, the progeny of control females mated to control males reared at 27degreesC. The developmental times of the immature stages were significantly different between groups. The survival rate in the immature stages varied significantly from 69.8% (Group C) to 34.7% (Group B). The average number of eggs produced per female and the longevity of females and males were not significantly different. The indices of population increase of Groups C, A and B were 286.2, 256.8 and 145.0, respectively. These results indicate that Group A offspring had physiological advantages, such as survival and population increase, compared to Group B offspring. The adaptive significance of summer diapause in the cotton bollworm is discussed in relation to the performance of offspring.

An artificial diet with lamb's quarters, Chenopodium album L. and wheat germ as its major ingredients was developed to rear larvae of the turnip moth, Agrotis segetum Schiff. for 16 successive generations. During the rearing period, 87-96% of the neonate larvae successfully pupated, of which less than 5% failed to emerge. Egg production of moths from diet-fed caterpillars averaged 1,000, with about 90% of the eggs hatching. A rearing technique for assuring a high survival rate, and performances of turnip moths under different rearing conditions are described.