S. M. Purushothaman ¹, Ambili S. Nair ¹, B. Renjan ¹, K. Karthikeyan ¹

Affiliations
1 Regional Agricultural Research Station, Pattambi, Kerala, IN

Abstract

Spotted pod borer, Maruca vitrata (Geyer) is a major constraint in the production of grain cowpea. The pest causes losses in grain yield of cowpea ranging from 20 to 60 per cent. In order to manage the pest, field experiments were conducted at four farmers fields during rabi 2010-2011. The study revealed that the pest can be managed effectively by spraying profenophos @ 1ml/litre at the time of flowering, Bacillus thuringiensis @ 1g/litre one at the time of flowering and next one was at 15 days later, Beauveria bassiana @ 20 g/litre at the time of flowering and other one was at 15 days interval and carbaryl @ 4 g/litre at the time of flowering. At harvest, the treatments recorded the per cent pod borer incidence of 6.99, 7.40, 7.86 and 8.96, respectively. Significantly higher grain yield was recorded in profenophos (817.18 kg/ha), Bacillus thuringiensis (754.89 kg/ha) and Beauveria bassiana (748.66 kg/ha) and carbaryl (669.31 kg/ha) treated plots.

Keywords

Spotted Pod Borer, Maruca vitrata, Bacillus thrungiensis, Cowpea.

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K. Karthikeyan ¹, Sosamma Jacob ²

Affiliations
1 Regional Agricultural Research Station, Pattambi 679 306, Kerala, IN
2 College of Horticulture, Vellanikara 680 656, Kerala, IN

Abstract

Laboratory studies were conducted during the year 2005-2006 to find out the efficacy of the white muscardine fungus, Beauveria bassiana (Balsamo) Vuillemin and the entomopathogenic nematode, Heterorhabditis indica (Poinar) against adult and grubs of rice blue beetle, Leptispa pygmaea Baly. B. bassiana caused a cumulative adult mortality of 56.67-80.00 per cent at 105-109 spores ml^-1 and the LC₅₀ value was 2.26x10⁴ spores ml^-1. The entomopathogenic nematode, H. indica caused a cumulative mortality of 66.67-91.67 per cent at concentrations of 5IJs to 9IJs in the grubs of L. pygmaea. The cumulative LC₅₀ value was 3.83IJs. The mortality of L. pygmaea was found to increase with reducing dose and increasing exposure period of both B. bassiana and H. indica. The effective pathogenicity of B. bassiana and H. indica against L. pygmaea is reported for the first time.

Keywords

Beauveria bassiana, Heterorhabditis indica and Rice Blue Beetle.

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K. Karthikeyan ¹, Sosamma Jacob ², S. M. Purushothman ¹, Smitha Revi ¹

Affiliations
1 Regional Agricultural Research Station, Kerala Agricultural University, Pattambi, 679 306, Kerala, IN
2 College of Horticulture, Kerala Agriculturtal University, Vellanikara, Trichur-680 656, Kerala, IN

Abstract

Field experiments were carried out to evaluate the efficacy of spinosad 45 SC, a biological product from actinomycetes, Saccharopolyspora spinosa @ 45 and 54 g a.i/ha in comparison to three other insecticides, viz., lambdacyhalothrin (12.5 g a.i./ha), chlorpyriphos 50% + cypermethrin 5% @ 344 g a.i./ha and monocrotophos @ 500 g a.i./ha as check against major insect pests of rice at Regional Agricultural Research Station, Pattambi, Kerala Agricultural University for three seasons viz., Kharif 2005, Rabi 2005 and 2006. Pooled analysis of three crop seasons indicated that spinosad @ 54 g a.i./ha was the most effective against rice stem borer, gall midge, leaffolder and whorl maggot. It caused 63 and 49 per cent reduction in dead hearts and white ears, respectively. The lower dosage of spinosad @ 45 g a.i./ha reduced whorl maggot infestation by 34 per cent. Spinosad @ 54 g a.i./ha resulted in 94 per cent reduction in leaffolder and 50 per cent reduction in gall midge infestation. Spinosad treatment also resulted in 14 per cent increase in rice yield. Spinosad caused no significant effect on spider population and was safe to spiders that predominate the predatory fauna in rice. Monocrotophos and lambdacyhaiothrin significantly reduced the spider and larval parasitoid populations in the rice ecosystem.

Keywords

Leaffolder, Rice Gall Midge, Spinosad, Stem Borer, Whorl Maggot.

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K. Karthikeyan ¹, Sosamma Jacob ², S. M. Purushothaman ¹

Affiliations
1 Regional Agricultural Research Station, Kerala Agricultural University, Pattambi-679306, Kerala, IN
2 College of Horticulture, Kerala Agricultural University, Vellanikkara-6, Thrissur, Kerala

Abstract

Field evaluation of two egg parasitoids, Trichogramma japonicum Ashmead against rice stem borer, Scirpophaga incertulas (Walker), and Trichogramma chilonis Ishii against leaf folder, Cnaphalocrocis medinalis (Guenee), was carried out in farmers' fields in three locations at Karakkad village, Palakkad district, Kerala, during three seasons in 2003 and 2004 in comparison with insecticide application. Release of T. japonicum @ 100000/ha followed by application of azadirachtin 1 per cent against yellow stem borer reduced dead hearts from 12.21 to 91.02 per cent and from 27.4 to 58.2 per cent over insecticide application during kharif and rabi seasons, respectively. Incidence of white ears was reduced by 72.41 to 92.86 per cent. T. chilonis reduced leaf folder damage by 41.68-98.60 per cent over conventional insecticide application. Release of egg parasitoids in rice resulted in an increase of yield by 25.79-45.13 per cent over insecticide treated plots, with a mean cost-benefit ratio of 1:2.6 and 1:1.9 in parasitoid released and insecticide applied plots, respectively.

Keywords

Cnaphulacrocis medinalis, Rice, Scirpophaga incertulas, Trichogramma chilonis, Trichogramma japonicum.

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K. Karthikeyan ¹, S. Jacob ², S. M. Purushothaman ¹

Affiliations
1 Regional Agricultural Research Station, Kerala Agricultural University, Pattambi 679306, Kerala, IN
2 College of Horticulture, Kerala Agricultural University, Vellanikara, Thrissur, IN

Abstract

Four field experiments conducted to evaluate the efficacy of cartap hydrochloride @ 1 kg a.i./ha in comparison with check insecticide carbofuran during 1999 (I crop season), 2000 (I crop season) and 2001 (I and II crop seasons) showed that cartap hydrochloride treatment in nursery five days before pulling rice seedlings had reduced incidence of dead hearts (35.6 %) and white ear (28.4 %) caused by yellow steniborer, Scirpophaga incertulas Walker and reduced leaf damage by leaf folder, Cnaphalocrocis medinalis Guenee by 47.7 percent with increased grain yield in comparison with check insecticide (carbofuran) drenched seedlings. The cartap hydrochloride drenched seedlings supported higher population of natural enemies like spiders (Tetragnatha sp.) while other natural enemies like damselflies (Agriocnemis sp.), green mirid bugs (Cyrtorhinus lividipennis) and larval parasitoids (Stenobracon sp.) were on par with the untreated plots.

Keywords

Carbofuran, Cartap Hydrochloride, Leaffolder, Natural Enemies, Rice, Stem Borer.

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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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