Bio-ecology of Major Insect-pests of Brinjal, Solanum Melongena L. And Development of Management Modules For Shoot and Fruit Borer, Leucinodes Orbonalis Guenee

Abstract

The present investigation "Bio-ecology of major insect-pests of brinjal, (Solanum melongena L.) and development of management modules for shoot and fruit borer, Leucinodes orbonalis Guenee" were conducted at Sardar Vallabhbhai Patel University of Agriculture & Technology, Meerut, during the Zaid, 2009 and 2010. During the extensive survey, twenty two insects were recorded on the brinjal crop in western plain zone of Uttar Pradesh. Among them, shoot and fruit borer (Leucinodes orbonalis Guenee.), whitefly (Bemisia tabac1), brinjal stem borer (Euzophera particella Rag.), hadda beetle (Epilachna viginctioctopunctata Fab.), leafhopper (Amrasca biguttula biguttula Ishida) are the major pests of economic importance. The leaf miner (Trachys herilla), cotton aphid (Aphis gossypiJ), green semilooper (Anomis f/ava), grey weevil (Myl/oceros undecimpustulatus), blister bettie (Mylabris pustulata), red cotton bug (Dysdercus koeinigil) and dusky cotton bug (Oxycarenus laetus) were recorded as minor pests. The other insect pests recorded on the crop were of less importance and extent of their damage was found without much economic loss. As regards the natural enemies the lynx spider (Oxyopes javanus Thorell.), one species of ladybird beetle (Coccinella septempunctata), Hover fly (Toxomerus geminates), Praying mantis (Mantis spp.) and Green lace wing bug (Chrysoperla c~rnea) were recorded. The study of infested shoot of L. Orbonalis elicited that infested shoot first appearance in the month of April and its maximum infestation reached by second fortnight of May. Further, the shoot infestation was observed with positive association with temperature, whereas rainfall do not exert any significant effect and relative humidity had negative effect on shoot infestation of L. orbonalis. The observations of fruit infestation of L. orbonalis revealed that its infestation gradually increases until it reached the peak in the month of May and it was independent of the effect of morning and evening relative humidity. However, temperature and rainfall had detrimental effect on the infestation of this pest. The activity of A. biguttula bigutula, Bemisia tabaci and Epi/achna viginctioctopunctata were found in field in 12th standard week during both the years. The maximum population of A. biguttula bigutula and Epilachna viginctioctopunctata were recorded in 19th standard week during both the years, except Bemisia tabaci which recorded its in 18th standard week during both the years. The stem borer was appeared in last April. The maximum infested stem was recorded in 19th standard week during both the years. The 5% shoot/fruit infestation level gave the maximum benefit (1 : 35.25). Therefore, 5% shoot/fruit damage was found as economic threshold level (ETL) of L. orbona/is. The total life cycle of brinjal shoot and fruit borer took less duration at 35°C temperature and 90% relative humidity as compare to 30°C, 25°C temperature, 60% and 90% relative humidity during both the years, respectively. The larval period, adult longevity and fecundity of L. orbonalis took less duration at 35°C temperature and 90% relative humidity as compared to other temperature and relative humidity. The efficacy of different IPM modules against L. orbonalis manifested that Module-V (installations of pheromone trap @ 5 traps/acre for monitoring the population of L. orbonalis + six release of egg parasitoid, Trichogrammp chilonis @ 1.0 Lakh/ha initiated with flowering and subsequent at 10 days intervals + three sprays of NSKE (5%) at 60, 80 and 90 days after transplanting· + one spray of Bt @ 1500 ml/ha at 70 days after transplanting + one spray of imidacloprid 17.8 SL @ 0.5 ml/litre at 100 days after transplanting) had the least shoot infestation and fruit (number and weight basis) infestation of L. orbonalis followed by Module-VI (installations of pheromone trap @ 5 traps/acre for monitoring the population of L. orbonalis + Six release of egg parasitoid, Trichogramma chilonis@ 1.0 Lakh/ha initiated with flowering and subsequent at 10 days intervals + three sprays of NSKE (5%) at 60, 80 and 90 days after transplanting + one spray of entomopathogenic nematode @ 1500 g a.i./ha at 70 days + mechanical clipping of infested terminal shoots at weekly intervals + one spray of imidacloprid 17.8 SL@ 0.5 ml/litre at 100 days after transplanting). The efficacy of eight modules in respect of fruit yield, The Module-V reported maximum yield (248.42 q/ha) followed by Module-VI (240.72 q/ha). While in 2010 the maximum yield (247.44 q/ha) was found in Module-V followed by Module-VI (236.83 q/ha). As regards the cost benefit ratio of eight modules, Module-V had the maximum C: B ratio (1: 8.13) followed by Module-VI (1: 6.26). The major activity of moths were recorded in last week of March (14th standard week) to first week of May (19th standard week), while minor activity period was last June.