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K. Karthikeyan ¹, A. V. Rangarajan ¹, M. Muthuswami ¹

Affiliations
1 Department of Entomology, Tamil Nadu Agricultural University, Coimbatore 641 003, Tamil Nadu, IN

Abstract

Ten natural enemies were observed to attack insect pests of neem tree, Azadirachta indica A. Juss in Tamil Nadu, India. Among them, coccinellids, Jauravia pallidula Motschulsky, Chilocorus nigrita (Fabr.); and spiders, Platythomisus sp. and Cheiracanthium sp. were found feeding on scale, Parlatoria orientalis Rao and mealybug, Pseudococcus gilbertensis Beardsley. The thrips, Podothrips sp. was found to be predacious on the scale, Parlatoria orientalis Rao. Spider, Olios sp. was found to attack ash weevil, Myllocerus viridanus (Fabr.). The braconids, Apenteies macchaeralis Wilkinson and Fornicia sp. were found to parasitize the leafwebber, Loboschiza koenigiana Fabr. and the slug caterpillar, Aphendala cana (Walker). The egg parasitoid, Anastatus sp. was observed parasitizing eggs of bark bug, Halys dentata Fabricius. All the above mentioned natural enemies were recorded for the first time in the neem ecosystem.

Keywords

Azadirachta indica, Insect Pests, Natural Enemies.

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M. Muthuswami ¹, R. J. Rabindra ¹, S. Jayaraj ¹

Affiliations
1 Department of Agricultural Entomology, Centre for Plant Protection Studies Tamil Nadu Agricultural University Coimbatore - 641 003, IN

Abstract

Laboratory experiments were conducted to evaluate the efficacy of certain adjuvants possessing phagostimulant and UV-protectant properties in increasing the efficacy of nuclear polyhedrosis virus (NPV) against Helicoverpa (=Heliothis) armigera (Hbn.), An adjuvant - mix consisting of Frenchbean/cotton seed kernel extract 10% + crude sugar 10% + glycerol 1% + egg white 1% + whitening agent (Tinopal)0.1 % was the most effective in increasing mortality due to NPV in larvae of H. armigera. Crude sugar 10% along with either Frenchbean extract 10% or cotton seed kernel extract 10% also significantly increased the NPV mortality but these were not as effective as the treatments with adjuvant - mix with full complements of the different components. Either Frenchbean or cotton seed kernel extract - based adjuvant-mix recorded significantly lower LT₅₀ values than NPV used alone. Frenchbean/cotton seed kernel extract 10% + crude sugar 10% also recorded lower LT₅₀ values than NPV alone but were higher than those recorded by NPV + full complements of adjuvant - mix. Frechbean or cotton seed kernel extract-based adjuvantmixes were able to protect the virus from UV light. The differences in mortalities between UV -exposed and unexposed were not significant in virus treatment with adjuvants.

Keywords

Adjuvants, Phagostimulants, UV - Protectants, NPV, Helicoverpa armigera.

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M. Muthuswami ¹, R. J. Rabindra ¹, S. Jayaraj ²

Affiliations
1 Department of Agricultural Entomology Tamil Nadu Agricultural University Coimbatore - 641 003, IN
2 Department of Agricultural Entomology, Tamil Nadu Agricultural University Coimbatore - 641 003, IN

Abstract

The nuclear polyhedrosis virus (NPV) has heen found to be effective in the control of Helicoverpa armigera (Hbn.) on several crops (Jayaraj et al., 1989) including lablab been (Jayaraj et al., 1987). Studies on the influence of varieties of host plants on the activity of NPV are rather limited. Rabindra et al. (1992) studied the effect of different chickpea varieties on the NPV - control of H. armigera. The present study was carried out to find out the influence of lablab bean Dolichos lab lab (L.) varieties on the mortality caused by NPV in larvae of H.armigera.

Keywords

Lablab Bean, NPV, Helicoverpa armigera.

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M. Muthuswami ¹, R. J. Rabindra ¹, S. Jayaraj ¹

Affiliations
1 Department of Agricultural Entomology, Tamil Nadu Agricultural University, Coimbatore, 641 003, IN

Abstract

The groundnut, Arachis hypogaea L. is known to be attacked by nearly 52 species of insect pests including the gram pod borer, Helicoverpa armigera (Hbn.) and the tobacco cutworm, Spodoptera litura F. (Singh et al., 1990). These two species of insects feed on leaves and cause considerable damage by defoliation. Since insecticide resistance has been reported in both H. armigera and S. litura In India (Mehrotra, 1989), baculoviruses, particularly the nuclear polyhedrosis viruses (NPV) have been tried as microbial insecticides for the control of these pests. The NPV of H. armigera (HaNPV) has been found to control H.armigera on crops like chickpea (Rabindra and Jayaraj, 1988), pigeonpea (Muthiah and Rabindra, 1991), cotton (Dhandapani et 01., 1987) and sunflower (Rabindra et 01.1986). Similarly, successful control of S. litura with its NPV (SINPV) has been reported on tobacco (Ramakrishnan et 01., 1981), banana (Santharam et 01., 1988), cauliflower (Chaudhari and Ramakrishnan, 1980) and cotton (Jayaraj etal., 1981). But so far, the virus control of these pests has not been attempted on groundnut.

Keywords

Helicoverpa armigera, Spodoptera litura, Nuclear Polyhedrosis Virus, Control, Groundnut.

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R. J. Rabindra ¹, M. Muthuswami ¹, S. Jayaraj ¹

Affiliations
1 Centre for Plant Protection Studies, Tamil Nadu Agricultural University, Coimbatore 641 003, IN

Abstract

The usefulness of nuclear polyhedrosis virus (NPV) in the management of Helicoverpa (=Heliothis) armigera Hbn. on chickpea (Cicer arietinum L.) has been demonstrated through several field experiments (Rabindra and Jayaraj, 1988a ; Rabindra et al., 1989; Rabindra et al., 1992). The virus has been applied along with half the recommended doses of insecticides like endosulfan (Rabindra and Jayaraj, 1988b) and fenvalerate (Sathiah, 1987). Probit analysis of dosage-mortality responses of H. armigera larvae to fenvalerate-treated and untreated NPV showed that the activity of the virus was enhanced due to exposure to fenvalerate (Rabindra et al., 1991). This paper reports the results of a field experiment on the field performance of fenvalerate-treated NPV as well as NPV -fluvalinate combinations in the control of H. armigera on chickpea.

Keywords

Nuclear Polyhedrosis Virus, Fenvalerate, Fluvalinate, Helicoverpa armigera.

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