Biology and Evaluation of Bio - Pesticides and Novel Insecticides Against Brinjal Shoot and Fruit Borer, Leucinodes Orbonalis (Guenee.)

Abstract

The present investigation was carried during Zaid of 2019 and 2020 by focusing on different objectives of study. Results on seasonal incidence of various insect pests found that during Zaid 2019, the incidence of leaf hopper, white fly, aphid, thrips, shoot infestation and fruit infestation by L. orbonalis had commenced from 11, 12, 12, 15, 12 and 18 standard weeks and continued till 26, 24, 26, 23, 26 and 26 standard weeks with peak in 17, 19, 22, 19, 23 and 24 standard weeks, respectively. During Zaid 2020, the incidence of leaf hopper, white fly, aphid, thrips, shoot infestation and fruit infestation by L. orbonalis had commenced from 12, 12, 14, 14, 12 and 18 standard weeks and continued till 25, 24, 24, 18, 26 and 26 standard weeks with peak in 21, 17, 18, 15, 23 and 23 standard weeks, respectively. Influence of abiotic factors on brinjal insect pests revealed that entire insect pests had showed positive correlation with maximum and minimum temperatures during both the seasons, except whiteflies and thrips had showed negative correlation with minimum temperature during Zaid 2020. Whereas relative humidity of morning and evening hours and rainfall showed negative correlation for the entire sucking insect pests recorded during both the seasons, except thrips with rainfall which showed positive correlation during Zaid 2019. Morning relative humidity had showed negative correlation with shoot infestation and fruit infestation caused by L. orbonalis, whereas evening relative humidity had 225 showed negative correlation with shoot infestation and positive correlation with fruit infestation during both the seasons. Biology of brinjal shoot and fruit borer revealed that single female could lay around 170 eggs. Incubation period of the eggs varied from 4.25-4.60 days. Total larval and pupal period range was observed on an average between 13.79-14.19 and 6.30-7.90 days, respectively. Adult longevity ranges of male and female were found on average between 2.80- 3.65 and 5.15-5.65 days, respectively. Total life cycle on an average of 25.78 and 28.11 days of male and female was recorded, respectively. The bio-efficacy of bio-pesticides and newer insecticides revealed that among the entire treatments spinosad 45% SC @ 150 ml/ha was found most effective in controlling shoot and fruit borer. The plots treated with Bacillus thuringiensis were found safe against natural enemies population (Coccinellids and Spiders).The maximum fruit yield was recorded in the treatment spinosad 45% SC @ 150 ml/ha and lowest fruits yield was obtained in untreated control. The treatment emamectin benzoate 5% SG @ 250 gm/ha was found with maximum incremental cost benefit ratio of 1:14.84 whereas, minimum ICBR (1:1.75) was observed in the treatment neem oil (1500 ppm) @ 2500 ml/ha.