Morphology of female perineal pattern (area around anus and vulva) of the root knot nematode (Meloidogyne spp.) is studied to identify the species under the genus as this was originally proposed by Chitwood (2). Several attempts (7,8,6,4,3) have been made to improve the technique for preparation and photographing of perineal patterns of Meloidogyne spp. Most of the cases cuticular patterns are photographed to record the morphological characters therein and stored for a short period and later disposed off. However, preservation of the patterns for subsequent study is much not known to those working with routine identification of Meloidogyne spp. In fact, the patterns on the Meloidogyne spp. female perineum disappear with the time due to dehydration and decaying of adhering body tissues. This study revealed that the patterns prepared from root material processed by NaOCl–Acid Fuchsin method (1) are good enough for preservation of patterns on anhydrous glycerine mounted glass slides. There are good numbers of glass slides of perineal patterns prepared for identification of root knot nematodes from West Bengal, India during 2002. Mature female specimens dissected from galled root tissue stained by NaOCl–Acid Fuchsin and later stored in acidified glycerol. The full grown females were placed in a drop of clear glycerol on glass slide and cut into two halves with the help of modified razor blade to remove the tissues adhered to the portion. The posterior half retaining perineal cuticular pattern of 3-5 specimens is then placed into a drop of 45% lactic acid on the one onside of the same slide for five minutes for easy clearing of body tissues. Fine tip of peacock feather designed for the purpose was used to remove the debris from the inner side of the pattern. The female cuticle is finally trimmed in
A B S T R A C T During a random survey, one isolate of entomopathogenic nematode from ginger rhizosphere was collected from Faizabad district of Uttar Pradesh (India). Morphological and morphometric studies identified the isolate as Steinernema carpocapsae. This was further confirmed by ITS-rDNA sequences analysis. Phylogenetic was constructed for studying relationship with known isolates. Pathogenic potential of the isolate of S. carpocapsae (IISR-EPN 06) on the larva of shoot borer (Conogethes punctiferalis), hairy caterpillar (Euproctis sp.) and greater wax moth (Galleria mellonella) was found under in vitro condition. Further this isolate displayed high virulence on above insect species. This study reported occurrence of a isolate of S. carpocapsae from ginger rhizosphere from India. This indigenous isolate could be investigated further for managing insect pests of ginger.
crop in West Bengal, India. This crop is commonly affected by stem rot and leaf spot disease (4) caused by two different genera of bacteria Xanthomonas axonopodis pv. betlicola Patel et al. (Vauterin et al.) and Pseudomonas betle Ragunathan (Săvulescu). Two bacterial pathogens enter into the host through stomata, hydathode and injury. Both the bacteria produce prominent dark brown lesions at any portion of the vine stem. Surface of such lesion becomes sticky in humid condition. On the leaf, small to large, circular to irregular and/or angular brown coloured spots and marginal leaf blight symptoms are produced by both the bacteria. All types of spots are surrounded by yellow halo or the halo is present in between brown and green tissue. At the underside of the leaf, the brown lesion is encircled by a water soaked zone or water soaked area which is found in between brown lesion and green tissue in marginal blight. Frequently both the bacteria have been detected from the same leaf spot or stem lesion (3, 4) in different plantation. This fact created an interest to find out whether the interaction of the two bacteria had any effect on the size of lesion. Leaves of betelvine (cv. Bangla Pan) were collected from farmers' Boroj. Bacterial suspension was prepared by adding sterile distilled water in the tube containing 48 hrs old slant culture of the bacteria. The tube was properly shaken to form uniform suspension (10 cell/ml). Afterwards, with the help of a hypodermic syringe, the bacterial suspension was injected in the veins of betel leaves (6). Upon injection, the leaf tissue adjacent to the injected vein became water soaked. The inoculated leaves were kept in polypropylene bags containing a moist cotton wool. After blowing air into the bags, the mouth of the bag tied with a rubber band. These polypropylene bags were then incubated at 28 ± 1°C in BOD incubator.
The incidence of red spider mite, Oligonychus coffeae on tea crop was maximum during the month of April to May-June and September-October (2011).The minimum number of mites were recorded from July-August and November (2011) to February (2012).The data taken from 1 st week of April, 2011 to last week of March, 2012.That population build up of O. coffeae showed a significant positive correlation with the maximum temperature and minimum temperature (r = 0.320 and r = 0.268, respectively).Whereas, the red spider mite population was negatively correlated but significant with average relative humidity (r = -0.357).Rainfall had a negative non-significant correlation with the mite population (r = -0.049).
belonging to the family Malvaceae, is a popular and commercially cultivated vegetable crop of tropical and subtropical parts of the world. India ranked first in okra production in the World and major okra producing Indian states are Uttar Pradesh, Bihar, Orissa, West Bengal, Andhra Pradesh, Karnataka and Assam (1). Okra fruit is very rich in fats, carbohydrates, vitamins like A & B vitamins and minerals such as calcium, iron, magnesium and potassium (2). Apart from these, the fruit is very useful against genito-urinary disorders, spermatorrhoea and chronic dysentery (7). The average production of okra in India is about 57.84 lakh tons and productivity 11.6 tons/ha during 2010-11 (1). H o w e v e r , o ne of the major constraints for okra production is heavy infestations caused by several insect pests which not only exert quantitative loss but also qualitative loss to the crop. As many as 72 insect species have been recorded on okra (9). The occurrence and intensity of damage caused by them varies from different crop growth stages, regions and seasons. Again, infestations by sucking insect pests not only affect the crop but also hamper the crop health by transmitting pathogenic diseases (8, 3). Kanwar & Ameta (5) recorded 48.97 % reduction in pod yield due to attack by the insect pests. Several studies have been carried out on various aspects of the insect pests on okra. However, a very little information is available from the red lateritic zone of West Bengal. The incidence and dynamics of insect pests on okra are essential to develop a sustainable management practices. Therefore, the present investigation was carried out to generate information on the incidence and abundance of insect pests infesting okra.
silkworm (Bombyx mori) is prone to several foliar diseases caused by fungi, bacteria, virus and mycoplasma. Among them, powdery mildew (Phyllactinia corylea), leaf rust (Peridiopsora mori), Pseudocercospora leaf spot (Pseudocercospora mori), Myrothecium leaf spot (Myrothecium roridum) and sooty mold (Ascomycetes and Deutoromycetes fungi) are major foliar diseases of mulberry in the eastern and north eastern India (7,8). About 10-15% leaf yield loss occurs due to powdery mildew, leaf rust and leaf spot diseases (3,9). Besides, these diseases also reduce leaf quality drastically leading to poor silkworm rearing. Qadri et al. (11, 12) reported crop loss up to 54.56% and 55.59% at maximum disease severity of leaf spot and powdery mildew, respectively.
Population dynamics of major insect pests and their natural enemies on cabbage were studied at Bidhan Chandra Krishi Viswavidyalaya (BCKV), Kalyani, West Bengal(India) during rabi season of 2011-12 and 2012-13. Experiment was laid out in Randomized Block Design with three replications. Cabbage (cv Rareball) seedlings were transplanted in the plot of 9 m area with 45cm x 45cm spacing. Observation was recorded at weekly interval from randomly selected five plants /plot. Peak population of diamond back moth (DBM) was recorded on 1 March and 23 February with13.60 and 14.33 larvae /plant during 2011-12 and 2012-13 respectively. Cabbage aphid reached its peak on 9 February (14.17 aphids/inch leaf) and 16 February (11.03 aphids/inch leaf) of 2011-12 and 201213, respectively. Highest parasitized larvae of diamond back moth by Cotesia plutellae were found on 15 and 8 March with 10.42 and 10.50% larval parasitisation during both the seasons, respectively, whereas maximum coccinellid was observed on 23 February of 2011-12 and 2012-13 crop seasons with 11.67 and 9.67 coccinellids/ 5plants, respectively. Both maximum and minimum temperature had major role to build up the population of diamond back moth, C. plutellae and coccinellids beetle while aphid population was enhanced only by maximum temperature. Relative humidity and rainfall had negative influence on pests and natural enemies during the study period.
