Srivilliputtur, India
Srivilliputtur, India

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Himantharaj M.T.,Research Extension Center | Vindhya G.S.,Central Scricultural Research and Training Institute
Indian Journal of Sericulture | Year: 2013

Mulberry leaf is the exclusive food for the silkworm, Bombyx mori. The growth and development as well as the quality of cocoons are largely dependent on the nutritional status of the mulberry leaves (Bhuyian, 1981; Ito and Arai., 1963). Mulberry leaf quality is influenced by factors like variety, climate, fertilizers, water management and cultural practices (Krishnaswami et al., 1970). Ë number of practices are employed to assess the quality of mulberry leaves. These include thickness, weight per unit leaf area, stiffness, specific gravity as well as percentage of intercellular cell sap and its concentration (Mallikarjuna et al., 2000). Also, the'leaf quality can be evaluated by chemo assay and bioassay (Yoshida, 1955). Assessment of leaf quality through bioassay, considering silkworm rearing performance and cocoon quality as yardsticks, is understood to be one of the straight and accurate methods. However, the method is laborious, time consuming and difficult to conduct full rearing if a large number of varieties or treatments are to be evaluated. In India, to tide over this problem, moulting test is adopted to shortlist the mulberry varieties or treatments (Benchamin and Anantha Raman, 1989; Bongale and Chaluvachari, 1993). In sericulturally advanced countries, different methods viz., fasting test in China (Takeuchi; 1961; Ting Zingetal, 1994) and Keburui test in Japan (Anonymous, 1997) are employed for understanding the mulberry leaf quality. As these tests have so for not been tried in India, attempts have been made in the present study to document the efficacy of Keburui test as an alternative to the conventional moulting test for understanding the quality of the mulberry leaves.


Sakthivel N.,Research Extension Center | Balakrishna R.,Regional Sericultural Research Station | Qadri S.M.H.,Central Sericultural Research and Training Institute
Journal of Biopesticides | Year: 2011

Comparative efficacy of user friendly water jetting technique by diverting a portion of irrigation water through a garden hose and chemical measures [0.1 % dichlorvos (76EC) / 0.05% dimethoate (30 EC)] practised by farmers against the major sucking pests of mulberry was studied. Two treatments with water jetting at 15 and 25 days after pruning (DAP) of mulberry plants was more effective in control of papaya mealybug than all concurrent chemical measures viz. two sprays of dichlorvos, dichlorvos followed by dimethoate, dimethoate followed by dichlorvos and two sprays of dimethoate. Against spiralling whitefly and jassid water jetting exhibited at par results with two sprays of dimethoate and dimethoate followed by dichlorvos but superior to the rest of the chemical measures. But against thrips, it was recorded lower efficacy than two sprays of dimethoate and dimethoate followed by dichlorvos, at par with dichlorvos followed by dimethoate and better than two spray of dichlorvos. Water jetting in mulberry garden showed slight or no deleterious effect on predatory coccinellids and spiders whereas there was drastic reduction in their population on chemical measures. However, the additional treatment of water jetting a third time at 35 DAP supported to reduce the population of all sucking pests in a greater extent constantly till 45 DAP and the highest population of natural enemies in the water jetted plots also worked to keep the pest population reduced which resulted in higher leaf yield and economy than all chemical measures. © JBiopest. 270.


Isaiarasu L.,ANJA College Autonomous | Sakthivel N.,Research Extension Center | Ravikumar J.,Regional Sericulture Research Station | Samuthiravelu P.,Research Extension Center
Journal of Biopesticides | Year: 2011

A preliminary survey on the incidence of silkworm diseases in ten selected sericulture farms near Srivilliputhur, a hub of sericulture activity in the Virudhunagar district of Tamilnadu, India showed that the incidence of the bacterial diseases, flacherie is quiet common in this region followed by the fungal diseases, muscardine and the viral diseases, Grassarie. Biochemical characterization of the microbes in the haemolymph of diseased silkworm collected during the survey indicated the presence of Bacillus sp., Streptococcus sp., Staphylococcus sp. And Pseudomonas sp. in the culture. The nature of fungal species however, could not be ascertained due to several handicaps including the difficulties encountered during their culture. Studies were carried out in vitro to assess the efficacy of some herbal extracts for the containment of these microbes through turbidimetry analysis and zone of inhibition test. The observations made during this study revealed that the aqueous and alcoholic crude extracts of three herbs such as, Acalypha indica, Ocimum sanctum and Tridax procumbens are effective against these microbes causing flacherie and muscardine diseases in silkworm. The comparison of their effects indicated that alcoholic extracts were generally more effective than aqueous extracts and that the extracts of Tridax procumbens are very effective against these microbial pathogens followed by the extracts from Ocimum sanctum and Acalypha indica. Extensive studies using these extracts on the growth and cocoon production of the mulberry silkworm, Bombyx mori L. are likely to throw much light on the possibility of using such extracts as a prophylactic measure during silkworm rearing to improve silk production. © JBiopest. 255.


Justin Kumar J.,Central Sericultural Research and Training Institute | Chandrasekharan K.,Research Extension Center
Indian Journal of Sericulture | Year: 2014

The silkworm breeds are either susceptible or resistant to the infection of various types of densonucleosis viruses. The susceptibility/resistance of silkworm to the BmDNV infections is controlled by single gene under recessive or dominant state. Productive and BmDNV resistant silkworm breeds could be evolved by transferring desirable meritorious traits and resistant gene from donor parents for the economic benefit of silk cocoon production. In case of BmDNVl infecting silkworms, the non-susceptibility is linked to two recessive genes, nsd-1 and nsd-2 and one dominant gene, Nid-1. The BmDNV2 infecting the silkworms, the nsd-2 gene controls the non- susceptibility and in case of BmDNVZ (or BmDNV3), nsd-Z, controls non-susceptibility to BmDNV-Z infection. The success of a breeder will be in harnessing the homozygous non-susceptible genes into the breed he aspires to develop. In the process of studying the non-susceptible genes to BmDNV infection has thrown light on the genetic linkages associated with these genes of interest.


Sakthivel N.,Research Extension Center
Indian Journal of Sericulture | Year: 2014

Shoot cum bunch feeding method of tapioca leaves registered significantly highest cocoon yield, shell yield and silk ratio of eri silkworm, Samia cynthia ricini Boisduval in summer, rainy and winter seasons. The next best method was shoot feeding followed by leaf cum bunch feeding and bunch feeding. Leaf feeding method was recorded least except that of winter season in which it was on par with bunch feeding.


Sharma S.P.,Research Extension Center
Indian Silk | Year: 2013

Stink bug is a known predator of tasar silkworm in early instars. But, it turns out to be bio-control agent of tasar against leaf gall. The author dwelling upon the issue, suggests to cash on this potential and use it as a bio-control agent to protect tasar silkworm.


Sakthivel N.,Research Extension Center | Qadri S.M.H.,Central Sericultural Research and Training Institute
Indian Journal of Sericulture | Year: 2013

The jaggery solution and soya flour were supplemented with senescent tapioca leaves at different dosages and fed to eri silkworm,Samia cynthia ricini Boisduval during fifth instar and their effect on the economic traits was studied. The important economic parameters such as ERR %, cocoon yield (kg/100 dfls), shell yield (kg/100 dfls) and SR(%) of eri silkworm reared on senescent tapioca leaves were drastically reduced (46.24,21.214, 1.824 & 8.60) compared to the normal matured leaf (96.77, 74.105, 11.287 & 15.23). Fortification of the senescent leaf with jaggery solution and soya powder exhibited significant improvement in all treatment. However, maximum enhancement (72.94, 44.849, 5.650 & 12.60) was observed when the leaves were supplemented with 10% jaggery solution + soya powder @ 10g/100g leaves followed by 10% jaggery solution + soya powder @ 5g/ 100g leaves (70.37,43.329, 4.641 & 10.71).


Sakthivel N.,Research Extension Center
Indian Journal of Sericulture | Year: 2013

The comparative efficacy of Dichlorvos and dimethoate solely and in combination with neem oil and fish oil rosin soap (FORS) against spiralling whitefly, Aleurodicus dispersus Russell (Hemiptera: Aleyrodidae) and papaya mealybug, Paracoccus marginatus Williams Granara de Willink (Hemiptera: Pseudococcidae) infesting tapioca (Manihot esculenta Crantz), the food plant of eri silkworm (Sarnia cynthia r/c/u/Boisduval) was assessed under field condition. The synergistic effect of dimethoate (0.05%) with neem oil (3%) as well as FORS (2%) have been found equally promising with highest reduction in population of spiralling whitefly (85.37 & 85.14%) and papaya mealybug (81.00 & 80.10%) than its sole application (76.18 & 70.16%) and when compared to the respective treatments of dichlorvos against spiralling whitefly (78.17 & 73.58 and 64.91%) and papaya mealybug (69.35 & 66.88% and 52.49%). These combinations also recorded highest leaf yield i.e. 669.73 & 672.16 g/plant and 655.94 & 657.27 g/plant in the plots treated against spiralling whitefly and papaya mealybug respectively than other treatments, over control (515.30 & 478.63 g/plant) and may be used to manage both the pests successfully in tapioca garden.


Siddiqui A.A.,Research Extension Center
Indian Silk | Year: 2010

Several measures need to be taken for the conservation of the Antheraea species, which are on the verge of extinction. The in situ conservation strategy is to be adopted that includes a system of protected areas of different categories including national parks, wildlife sanctuaries, national monuments, cultural landscapes, and biosphere reserves. Conservation of lepidopteran biodiversity should be taken up on priority to avoid extinction of many useful Antheraea species. Other strategies that are employed for the conservation includes forming the group for the job, which includes young scientists including technical staff having knowledge of conservation strategy for in situ conservation of each Antheraea species in different locations. The training is to be provided to the group members involved in biodiversity conservation in specialized institutes/centers. Molecular studies can be conducted periodically for each ecotype/accession to ensure the parental bimolecular status in the proceeding generations.


Three exotic encyrtid parasitoids viz., Acerophagus papayae, Anagyrus loecki and Pseudleptomastix mexicana, introduced in India during 2010 under the classical biological control programme against an outbreak of papaya mealybug, Paracoccus marginatus, an alien polyphagous pest, were evaluated on mulberry in Tamil Nadu. The nucleus culture of these three parasitoids were received from National Bureau of Agriculturally Important Insects, Bangalore, mass multiplied and released in mulberry gardens severely infested by papaya mealybug in 6 locations, 3 each at Virudunagar and Tirunelveli districts of Tamil Nadu @ 200 individuals per location during November 2010. An average of 10.4% parasitism and 9.7% reduction in papaya mealybug population was noticed a month after release of parasitoids and the population of the papaya mealybug was decreased gradually corresponding to the increase in percent parasitism @ 2, 3, 4 and 5th months. The population of papaya mealybug from the mulberry garden was almost completely eliminated with 96.6% at 6th month corresponding to 72.2% parasitism. Among the parasitoids released, the highest proliferation and field activity was observed in the case of A. papayae, which accounted for 75.6 - 81.7% parasitization followed by P. mexicana (9.3-24.4%) whereas A. loecki registered comparatively very poor performance (0.7-9.0 %) and its field recovery was not found 4 month after release in mulberry ecosystem of Tamil Nadu, India. © JBiopest 373.

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