Epizootics of an entomopathogenic fungus Entomophthora aphidis Hoggman on the pomegranate aphid aphispunicae passerini (Homoptera: Aphididae).
Thrips of late are becoming more resurgent in agro-ecosystems especially in India and South Asian countries. One of the reasons attributed is the development of resistance in them to groups of insecticides of organo phosphates, carbamates, synthetic pyrethroids, etc., which form the core of recommendation for thrips management. The chilli thrips, Scirtothrips dorsalis Hood, is no exception and is tending to be an unmanageable pest. In S. dorsalis, besides evidence of resistance, elimination of natural enemies like Orius sp. is evident, which also probably explains the thrips resurgence. Scirtothrips dorsalis is highly polyphagous and of late has become serious on grapes. The damage is manifested as scab on fruit rind, affecting internal and export markets. Fortunately, it does not vector any virus on grapes in India. Farmers have been reporting inefficacy of established chemicals like acephate, dimethoate, monocrotophos, etc. As grapes is an important cash crop of horticulture, management through insecticides, require alternate or new insecticides. So two trials in 2005 on cv. Bangalore Blue following April and October prunings were conducted at the Indian Institute of Horticultural Research (IIHR), Bangalore, S. India to evaluate two doses of a newer molecule viz. Clothianidin [Dantop] on S. dorsalis. Clothianidin 0.006%, Clothianidin 0.008% were compared with monocrotophos 0.05%, dimethoate 0.06% and acephate 0.1125%. There was an untreated check. Each treatment was replicated five times; a vine constituted a replicate. These data were subjected to ANOVA, after arc sine transformation. The critical difference (CD) at p < 0.05 was the test criterion. In the first trial it was found that all the insecticides tried were superior to check and were on par at p < 0.05. However, Clothianidin 0.008% gave the best control with a low mean of 0.26% berry damage/bunch as compared to 4.42% in the unsprayed check. The trend was the same in the second trial also with Clothianidin 0.008% giving the best control with 0.64% berry damage/bunch as compared to 8.49% in the unsprayed check. It was on par with acephate and monocrotophos, but significantly superior to Clothianidin 0.006% and dimethoate.
Verghese
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Indian Institute of Horticultural Research, Hessaraghatta Lake PO., Bangalore 560089, Karnataka, India. avergis@iihr.ernet.in
Sreedevi
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D000704:Analysis of Variance; D000818:Animals; D001042:Aphids / Q000187:drug effects* / Q000382:microbiology*; D004773:Entomophthora / Q000187:drug effects / Q000254:growth & development* / Q000472:pathogenicity; D007300:Insect Control; D007305:Insecticide Resistance; D007306:Insecticides / Q000494:pharmacology*; D029561:Lythraceae / Q000469:parasitology*; D010573:Pesticide Residues; D011157:Population Dynamics
D007306:Insecticides; D010573:Pesticide Residues