D. C. Sharma ¹, N. P. Kashyap ¹

Affiliations
1 Department of Entomology, CSK Himachal Pradesh Krishi Vishvavidyalaya, Palampur 176 062, H. P., IN

Abstract

Tea plant (Camellia sinensis (L.) O' Kuntze) is attacked by numerous insect pests, which causes considerable damage to the quality and quantity of tea. The most important pest attacking tea bushes in H. P. are purple mite, Calacarus carinatus (Green), thrips, Scirtothrips dorsalis Hood, leafroiier, Gracilaria theivora, Walsom, apbid, Toxoptera aurantii Boyer, mealybug, Nipaecoecus sp. and leafminer, Tropiomyts theae (Cotes). The important natural enemies associated in the tea orchards are Syrphis sp., Coccincella septempunctata Linn., Oxyopes sp. and parasitoid, Diaeretiella sp. Among the insecticides and biopesticides evaluated against natural enemies, deltamethrin, cypermethrin and ethion sprays were found highly toxic to Syrphis sp. and C. septempunctuata and their adult and larval population was not seen even on 7^th and 4^th days of spray, respectively. Neemark, Achook and B.t. (Dipel 8L) were quite safe to natural enemies. Endosulfan was relatively safe to Syrphis sp. but highly toxic to C. septempunctata.

Keywords

Insect-Pests, Pesticidal Effects, Predators, Parasitoids, Predation Potential, Tea Ecosystem.

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Prem Chand ¹, N. P. Kashyap ¹, D. C. Sharma ¹

Affiliations
1 Department of Entomology Himachal Pradesh Krishi Vishvavidyalaya Palampur 176 062, Himachal Pradesh, IN

Abstract

The effect of four commercially used insecticides on tomato crop was studied on Trichogramma chilonis Ishii and its parasitism under laboratory conditions. The toxic effect of these insecticides on 1,3, 5 and 7 day old eggs of Corcyra cephalonica (Stainton) parasitized by T. chilonis was also studied. Acephate (0.05 %) proved safer to the parasitized host as well as to the adult parasitoid. However, the emergence of adults from treated parasitized eggs was significantly lower than the untreated control.

Keywords

Egg Parasitoid, Insecticides, Trichogramma chilonis.

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D. C. Sharma ¹, U. S. Rawat ², A. D. Pawar ³

Affiliations
1 Department of Entomology and Agriculture HPKV, Palampur, IN
2 Central Biological Control Station, Sai Sadan Tank Road, Solan, Himachal Pradesh-173212, IN
3 Directorate of Plant Protection, Quarantine and storage, Faridabad, IN

Abstract

The influence of temperature (22, 24, 28, 32 and 37 °C) and relative humidity (45, 65, 85 %) on the development, survival, fecundity and predatory potential of Pharoscymnus flexibilis Muls. was observed. The optimum temperature and humidity for the development of different stages of P. flexibilis and predatory potential were observed to be 28°C and 65% relative humidity respectively. The beetles hibernate at 22°C and could survive for more than 175 days, while at 37°C, they died within 5-10 days. P. flexibilis was observed to consume on an average 1362, 2537 and 2110 San Jose Scale crawlers at 24, 28 and 32 °C, respectively throughout its larval and adult life span.

Keywords

Development, Longevity, Predatory Potential, Pharoscymnus flexibilis, Quadraspidiotus Perniciosus.

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