Influence of Host Plants on The Growth and Development of Cheilomenes Sexmaculata (Fabricius) (Coleoptera:Coccinellidae) Prey on Aphis Craccivora Koch

Allelochemicals and physical barriers such as wax of leaf surfaces, trichomes, cell wall thickness and lignifications of host plants play important role in unsuitability of prey to predatory lady beetles. Four economically important host plants of family Fabaceae (Phaseolus sinensis, Lablab purpureus, Vigna radiata and Vigna mungo) infested by Aphis craccivora (Hemiptera Aphididae) were selected for experiment to observe the growth pattern of one of the most potent predator of aphids, Cheilomenes sexmaculata (Fabr. ) (Coleoptera Coccinellidae). The significant variation was observed in the length and width of grubs of each instar stage of predator when preyed on A. craccivora on these host plants. The maximum growth of each instars were observed on P. sinensis followed by L. purpureus, V. radiata and V. mungo. The highest length (7.290.15mm) and (1.320.06mm) in width of 4th instar larvae was recorded on P. sinensis than other host plants at 19.450.55C and 60.851.015 % RH. This variation is observed significant by ANOVA test for length (F1=28922.7, F2=18.6, Pless than0.05) and for breadth (F1=13504.3, F2=44.1429, Pless than0.05). Similarly, the developmental period of C. sexmaculata was also found to be host plant dependent. The longest developmental period was recorded on V. mungo (17.60.24 days) and shortest on P. sinensis (14.000.02 days). This difference is also observed significant between each instars and host plant by analysis of variance test (F1=197.667, F2=60.333, Pless than0.05). It is observed that P. sinensis is most suitable host plants for the growth and development of Larvae of C. sexmaculata. V. radiata and V. mungo were the less suitable plants probably due to presence of allelochemicals and trichomes on the leaves which directly affect the searching efficiency of predator.