Efficacy of some plant extracts against larvae of American bollworm Helicoverpa armigera (Nouctuidae: Lepidoptera) special reference to the effect on peritrophic membrane)

Abstract

India is basically an agriculture based country and more then 80% populations depends on it India is basically an agriculture based country and more than 80% of Indian population depends on it. Agricultural productivity influences the Indian economy. Insect pests are known to cause significant damage to crops. The pesticide of plant origin is having nontoxic biodegradable and environmental friendly qualities. The frequent spraying of toxic chemicals developing resistance to the pesticide. Leaf powder of the plants like Argimone maxicana and Calotropis procera is prepared, Different doses of these plant extracts is given to the fourth instar stages of Helicoverpa armigera through feeding methods, To find their efficacy the experimental findings will be put under analysis using various perameters. The effect on midgut is also studied, Key word: Distillation plant, Acetone, Alcohol, Piptte, Castor leaves, Grams pods, larvae of Helicoverpa armigera, plant extract, Vails, Jars,Cotton. INTRODUCTION The problem of insect pest is intensified by a large number of insects of nuisance value to man and having a broad spectrum of their harmful effects .The most common example of this category is the Lepidopterain pests that are interfering in maintenance of a hygienic environment for healthy leaving. This moth is the single major pest for global plant agriculture.This moth and its close relatives over come chemical insecticide to attack over 100 crop plant species at an annual cost of over US $ five billion. The gram (Cicer aretinum) is an important vegetable crop grown in the country, unfortunately this vegetable crop suffers heavily from various insect pest and disease which reduces not only to its yield but also spoil the quality. Among the various pests the gram pod borer has been reported to cause maximum economic damage to the gram crops in India In agricultural pest management botanical insecticides are best suited for us in organic food production in industrialized countries but can play a much greater role in the production and post harvest protection of food in developing countries. The use of simple formulation of plants such as leaf, flower or seed powder extracts needs of to be popularized . Their being safe to non target organism, including human. METERIAL AND METHODS The selection of the pest was mainly based on the local pest problem and the rearing possibilities of the selected pest species under laboratory conditions. The gram pod borer Helicoverpa armigera belongs to order lepidoptera and family Noctuidae. It’s a phytophagous pest. For rearing, adults were collected from the field by light trap method. They were allowed to mate and lay eggs in glass troughs which contain moist soil. The sides of the troughs were provided with paper so that female could rest and lay eggs on them. Water was added to the soil to maintain the humidity. The honey soaked cotton was changed daily. Soon after hatching of the egg, the 1 st instar larvae transfered to plastic vials containing fresh castor leaves. After 3 rd instar stage the larvae were kept individually in plastic vials to avoid canabolism. The common weed belonging to the family paperveraceae were collected partly in the morning hours and washed thoroughly with tap water to remove any dust or pest adhering the plant product. The washed material was chopped into small pieces and dried in shed at room temperature. The fine powder was subjected to solvent extraction.27+3 o 75+5 o f temperature and humidity were provided. 14: 10 (hours) dark light period given. RESULTS AND DISCUSSION Calotropis procera (leaf extract) Mortality increases as the dose level increases. At the dose levels of 10,25,50,75 and 100ppm, the percent corrected mortality comes to 41.17,52.17,69.56,100 as compared to 8 percent mortality in control . There is a significant increase in the average larval periods. At the dose levels of 10,25,50ppm average larval period comes to 22.2,19.1and 20.0 respectively as compared to 6.0,9.2,6.0 days respectively. In control the average larval and pupal periods coms to 14.0,7.13 days respectively. There is no adult emergence at the dose leval of 75ppm and higher. The adult emerged out of the treated forth instar larva show reduced fecundity and fertility. Prolongation in preovi position period is occurred. Argimone maxicana(leaf extract) Higher dose levels are very effective at the dose of 10,25.50.75,and 100,the percent corrected mortality comes out to be 17.30,21.74 34.78,41.30,100as compared to 8 percent mortality in control.abormalities maily observed at a very high dose level which mainly affects the fecundity n fertility. © 2018 JETIR April 2018, Volume 5, Issue 4 www.jetir.org (ISSN-2349-5162) JETIR1804229 Journal of Emerging Technologies and Innovative Research (JETIR) www.jetir.org 42 The selected bio pesticides block the molting process at the level of synthesis of new cuticle and there by death occurs at exuviations. On treatment to larvae the effective doses were determined based on parameters mortality, abnormalities and reproductive potentiality of the emerged adults. In general the effect of the pest includes the fall in natality due to disruption in development and growth and increase in mortality due to toxic action and death during moulting because of inadequate mode of action by the plant extracts. Adverse effects on reproduction which includes the followinga) Occurrence of larvaepupae and pupae adult intermediate stage in capable of becoming adult. b) Adverse effect of larvae, such as darkening of skin and change in behavior. c) Reduction in fecundity and fertility. d) Suppression of f1 generation. The plant extract mainly affect the egg hatchability. Behavioural aspectTreated fourth instar larvae becomes sluggish at higher dose level. The body becomes very dark, they become very lethargic. Food intake capacity become slow down, the average pupal period increases at a higher dose level. MODE OF ACTION The prevailing view of mode of action is further supplicated the histopatholical studies on midgut of the larvae of Helicoverpa armigera treated with the plant extract of Argimone maxicana and Calotropic procera at the doses level of 25 ppm, 50 ppm, 75 ppm and 100 ppm respectively. The mid gut gets broken, dismantled and intermingled with the totally displaced epithelial cells. Thus it is concluded that both these biopesticides have enough potentiality to suppress the dangerous pest Helicoverpa armigera, a better scope for agriculture and environment. Table 1 Effect of plant extracts on mortality of 4 th instar larva of H.armigera Plant extracts Dose (ppm) Average larval period (days) Percent larval mortalit y Average pupal period (days) Percent pupal emergenc e Percent total mortalit y Percent correcte d mortalit y Percent adult emergence Calotropis procera (Leaf) 10 22.02 ± 0.28a 40 6.02 ± 0.14a 60 44** 41.17 56 25 19.01 ±006a 48 9.2 ± 0.48a 52 56** 52.17 44 50 20.02 ±0.22a 68 6.01 ± 0.15a 32 72 69.56 28 © 2018 JETIR April 2018, Volume 5, Issue 4 www.jetir.org (ISSN-2349-5162) JETIR1804229 Journal of Emerging Technologies and Innovative Research (JETIR) www.jetir.org 43 75 to100 100 NIL 100 NIL Argimone maxicana (Leaf) 10 19. 6 ± 0.34 16 9.02 ± 0 84 28* 17.39 76 25 20.01 ± 0.30a 20 9.04 ± 0.02a 80 40* 21.74 72 50 22.35 ±0.41a 36 9.02 ±0.64a 64 46** 34.78 60 75 21.4 ± 0.21a 40 9.1 ± 0.10a 60 100 41.30 54