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S. P. Sharma , Ram Kishore , K. Thangavelu , S. Rai

Abstract

The May-June beetle, Anomala blanchardi Blanch is one of the major pests of primary tasar food plants, Terminalia arjuna Bedd. and T. tomentosa W & A causing 10-15% loss to the foliage with an average incidence of 15-20 adults per bush. An experiment was undertaken to evaluate the effect of Amrutguard a Neem (Azadirachta indica A. juss) formulation on mortality and feeding inhibition efficacy against adults of A. blanchardi. Observations reveal that maximum mortality (77.77%) was recorded when adults of A. blanchardi were fed with 30 ppm Azadirachtin treated leaves as compared to control (6.66%). Results indicate that in the said concentration the excretion oflitter was minimum (0.39 g/treatment) vis-a-vis control (1.527 gl treatment). This reflects the minimum feeding due to strong antifeedant properties of Azadirachtin. The paper deals with the use of non-wood products of neem in the pest management thereby minimizing crop loss and load of insecticides in the forest ecosystem.

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P. K. Srivastav , S. N. Raina , K. Thangavelu

Abstract

2C nuclear DNA amounts and fruit (conventionally known as seed) characters were studied in 37 samples collected from 27 mother trees belonging to various taxa of genus Terminalia in section Pentaptera. There were significant differences between various taxa both in nuclear DNA amounts and fruit characters. The divergence and evolution in section Pentaptera was accompanied by very high as well as highly variable nuclear DNA amounts ranging from 8:01 to 9.66 Pg. The element of discontinuity in the distribution of DNA changes between complements was quite regular. The various taxa altogether fell into six cluster groups with an interval of 0.31 Pg. between the two adjoining groups whereas various genotypes of T. glabra and spontaneous hybrids further fell into five and four cluster groups with the interval of 0.3 and 0.55 Pg.respectively. This is probably the second case after Cassia where significant intra-specific nuclear DNA variation has been observed in trees. In the light of hybridization and nuclear DNA studies, there is indeed a case for considering T. glabra, T. berryi, T. coriacea, T. crenulata, T. alata and spontaneous hybrids as separate species and not as the varieties of T. arjuna and T. tomentosa. The nuclear DNA amounts exhibited no correlation with fruit characters of various taxa studied.

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S. P. Sharma , Ram Kishore , B. R. R. P. Sinha , K. Thangavelu

Abstract

Defoliators Anomala blanchardi Blanch, Tricliona picea Jacoby, T. variabilis Jac., Myllocerus viridanus Fab. and Notolophus antiqua Linn. are the major pests of primary tasar food plants, namely, Terminalia arjuna Bedd and T. tomentosa W&A causing 15-20% foliage unsuitable for silkworm feeding. The soil application of neem cake (60 kg/acre) and foliar spray of Azadirachtin (6.0 ppm) were found effective in suppressing growth and development of coleopteran grubs and lepidopteran larvae respectively. Based upon these finding, various control measures such as cultural (deep digging of soil), mechanical (collection and destruction of different developmental stages), soil application of neem cake, foliar application of Azadirachtin and combination of these four control measures (IPM) were taken up for evaluation of their efficacy. The averages of leaf yield per plant, leaf damage per cent and number of grubs per cubic feet for each treatment were recorded. Results reveal that IPM was effective (leaf yield/plant-4.266 kg, leaf damage - 11.25% and number of grubs/cft - 0.125) as compared to control (leaf yield/plant - 2.468 kg, leaf damage - 40% and number of grubs/cft. - 1.750) in controlling the defoliators. The foliage damage could be reduced by 71-87% over control by adopting IPM. The safe period for Azadirachtin was found to be 5 days for tasar silkworm, Antheraea mylitta D.

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P. K. Mishra , R. N. Singh , J. Jayswal , K. Thangavelu

Abstract

No abstract

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R. N. Singh , K. Thangavelu

Abstract

No abstract

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Ravindra Nath Singh ¹, Shashi Shekhar Sinha ¹, K. Thangavelu ¹

Affiliations
1 Central Tasar Research and Training Institute, Ranchi-835 303, IN

Abstract

A life-table was constructed under laboratory conditions for a little known Scelionid egg parasitoid Psix striaticeps Dodd on Canthecona furcellata Wolff. The female parasitoid survived for 12 days and oviposited intensively for 3.5 days. The net reproductive rate (R_o) representing the total births was 38.30. The population increased with an infinitesimal rate [r_m] of 0.275 and finite rate of 1.32 per female per day. A generation was completed in 13.25 days. Life-table analysis indicated the preponderance of females due to solitary parasitism and a balanced sex ratio due to superparasitism.

Keywords

Life-Table, Psix striaticeps, Canthecona furcellata, Hymenoptera, Scelionidae.

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