Experiments on development of Amblyseius longispinosus Evans (Acari:Phytoseiidae) as influenced by castor pollen as an alternate food and its interaction with sorghum mite, Oligonychus indicus Hirst (Acari:Tetranychidae) were conducted under laboratory conditions. A. longispinosus showed poor growth on castor pollen. Female and male developmental periods were 2.6 ± 0.30 and 2.42 ± 0.21 days on spider mites, 2.70 ± 0.89 and 2.68 ± 0.39 days on spider mites + castor pollen and 5.12 ± 2.03 and 3.89 ± 1.80 days on castor pollen alone, respectively.

At interaction A. longispinosus suppressed populations of O. indicusat 1:10, 1:20, 1:30, 1:40 and 1:50. Prey elimination was on 12th day in 1:10, 18th day in 1:20, 20th day in 1:30, 24th day in 1:40 and on 30th day in 1:50 ratio.

Laboratory evaluation of food consumption, food utilization, weight gain, development, fecundity and egg-hatchability were made from the beginning of the first instar to sixth instar on castor, groundnut, Indian bean, jute, sesame and sunflower. Total food consumption was highest on castor and lowest on jute. Development was fastest on castor, and castor was most efficiently digested followed by sunflower, sesame, groundnut, Indian bean and jute. Consumption index and digestive efficiency on all host plants declined with larval age. Digested portion of jute was most efficiently converted into body matter. Variations in fecundity and egg-hatchability for different host plants were statistically significant at P = 0.01. The differences in these parameters may be due to the variations in the nutritional quality of the hosts.

The development of phase phenism in L. erysimi involved function related changes in the activity of hydrolytic enzymes. The esterase activity decreased from first to third instar and then increased in the fourth instar and adults. The decrease in the third and the increase from fourth instar up to adults was more in alatae than apterae. The acid phosphatase activity was maximum in second instar. It decreased in the third and then increased again in the fourth instar and adults. The increase was more in alatae than in apterae. The alkaline phosphatase showed a similar trend but was in contrast to acid phosphatase and showed low activity in alatae as compared to apterae.

Per cent survival, larval period and weight, pupal duration and weight, emergence, adult longevity and fecundity of Heliothis armigera (Hubner) were affected by the pulse species on which it was reared. The pulses could be classified into two groups i.e. pigeon pea and chick pea which were suitable for growth, development and fecundity and black gram, sweet pea, green gram, broad bean and lentil which were unsuitable.

Polyphenism is a common feature in the mustard aphid, Lipaphis erysimi (Kalt.) in tropical countries. The function related changes in basic biochemical pool are reported during development of polyphenic forms. A gradual decrease in the protein content in this aphid was recorded, as the nymphs advanced in their instar number and reached adult stage. However, the protein content was significantly lower in the apterous forms as compared to alate. The number, density and mobility of protein bands varied as the nymphs passed through different instars and the number of bands was more in alate forms. The glycogen and trehalose contents showed a decrease upto the third instar and showed an increase in the fourth instar, but again declined in the adults of both the phases.