Pests infesting ornamental plants in hilly region of West Bengal.

Ornamental plants are grown widely to enhance the beauty of home gardens and community parks and gardens. But in recent years, a revolutionary change has taken place in floriculture as an enterprise by most of the growers and industrialists. Large scale cultivation of these crops as in case of other commercial crops has been plagued by many limitations. Attack by insects, mites and other pests is one of the important bottlenecks for successful production of these crops. As many as 65 insect pests have been recorded on different ornamental plants in Himachal Pradesh. Pest scenario varies from place to place with the variation in the agro-climatic conditions of the locality. Information on pest complex in a specific agro-ecosystem is very much essential in devising pest management strategies which would not only be economically feasible but also ecologically sound. However, such information on ornamental crops are scanty particularly from this region. Therefore, pest survey and surveillance was conducted for 3 consecutive years to take into account the pest scenario of some ornamental plants in mid-hill conditions of West Bengal. The survey was conducted at the farms of RRS, UBKV, Kalimpong; RRSS, UBKV, Pedong and other adjoining areas for 3 consecutive years during 2005-07. The ornamental plants like Gladiolus, Carnation, Anthurium, Gerbera, China Rose, Chrysanthemum, Bird of Paradise and Straw flower were taken up for the study. The crops were surveyed regularly for recording observations on the incidence of pests. A pocket lens (10X), insect collecting nets, glass vials and polythene bags were used for collection of insect pests for their proper identification in the laboratory with the help of the appropriate technical literature. Some pests were identified on the spot and some of them were brought to the laboratory for detailed study. They were preserved as dry specimen. Some specimens were sent to other institutes for authorized identification. Some specimens are yet to be identified. Based on their mode of occurrence and frequency, the pests were categorized as stray, occasional, sporadic and regular. On the basis of extent of injury made by the particular pests, they were grouped into pests of negligible, minor, moderate and major importance. All information explored from the field survey and surveillance were compiled and presented in the Tables 1 and 2. Twenty four different pests have been recorded infesting various ornamental plants at places in and around Kalimpong and Pedong. The pests with their systematic position and respective destructive stage have been presented in the Table-1. 99 The Journal of Plant Protection Sciences, 1(1) : 98-101, 2009 Presented data in the Table 1 revealed that eight homopteran, two thysanopteran and a mite pest constituted the sucking pest complex. The order lepidoptera and coleoptera was represented by seven and three pests respectively. In addition to this a dipteran leaf miner, grasshopper and snail were also recorded as pests of ornamental plants during the present study. Most of the pests have been reported for the first time from this region. However, some of the pests have been reported earlier by Satpathi et al. The Table-2 depicts the host range, nature of damage, mode of occurrence and status of pests infesting ornamental plants. Amongst the pests recorded five species i.e. Macrosiphoniella sanborni, Taeniothrips simplex, Tetranychus urticae, Helicoverpa armigera and Mylabris sp. have been categorized as major pests on their respective host plants. Earlier Helicoverpa armigera has been reported as an important pest of ornamental plants causing serious damage to the flowers (3, 7). The extent of damage in Himachal Pradesh in terms of percent bud infestation ranges from 10 to even 80% in various cultivars of carnation (2). Sohi and Singh (4, 6) have also reported Helicoverpa armigera and Tetranychus urticae as economically important pests of chrysanthemum. According to Rami Reddy and Janakiram (4) Macrosiphoniella sanborni is one of the serious pests of chrysanthemum. The thrips, Taeniothrips simplex has been reported as a major pest of gladiolus (1). Literature Cited Bhatti JS. 1996 Taxonomic studies in some Thripini (Thysanoptera: Thripidae). Oriental Insects 3: 373-82. Chauhan U Sharma KC. 2004 Insect pests of ornamental cropsidentification and management manual. Dept. of Entomology & Apiculture, Dr. Y.S. Parmar University of Horticulture and Forestry, Nauni-Solan, India. Multani JS Sohi AS. 2002 Helicoverpa armigera (Hubner) on carnation, Dianthus caryophyllus Linn. in Punjab. Insect Environment 8(2):82. Rami Reddy PV Janakiram T Rao TM. 2004 Screening of chrysanthemum germplasm for resistance to two spotted spider mite, Tetranychus urticae koch and bud borer, Helicoverpa armigera (Hb.). Journal of Ornamental Horticulture 7 : 80-84. Satpathi CR Pramanik A Chatterjee H. 1996 Insect-pests of important flowers and ornamental herbs in eastern Himalayan regions with special reference to Kalimpong. Annals of Entomology 14 :101-06. Sohi AS Singh D. 1995 Insect pests of ornamental plants. In: Advances in Horticulture. vol. 12 (eds. K.L. Chadha and S.K. Bhattacharjee). Malhotra Publishing House, New Delhi 110005, India, 913 pp. Sood A.K. 1988 Insect pest complex of ornamental plants in Himachal Pradesh. Thesis submitted to Dr. Y.S. Parmar University of Horticulture and Forestry, Nauni, Solan173230, Himachal Pradesh, India. 100 The Journal of Plant Protection Sciences, 1(1) : 98-101, 2009 Table 1 Pests infesting ornamental plants in hilly region of West Bengal Common name Green peach aphid Chrysanthemum aphid Anthurium black aphid Gladiolus aphid Cotton aphid Hard Scale Whitefly Leaf hopper Gladiolus thrips Carnation thrips Red spider mite Grasshopper Gram pod borer Tobacco Caterpillar Green Semilooper Leaf Webber Leaf Webber Bagworm Cutworm Blister beetle White spotted flea beetle Steel blue beetle Serpentine leaf miner Giant African Snail Scientific name Myzus persicae Sulz. Macrosiphoniella sanborni (Gillette) Unspecified Unspecified Aphis gossypii Glover Unspecified Bemisia tabaci Genn. Unspecified Taeniothrips simplex Morison Unspecified Tetranychus urticae Koch. Unspecified Helicoverpa armigera (Hub.) Spodoptera litura (Fab.) Plusia orichalcea Fab. Unspecified Lamprosema indicata (Fab.) Unspecified Agrotis segetum (Schiff) Mylabris sp. Monolepta signata Oliv. Altica sp. Liriomyza trifolii (Burgess) Achatina fulica Bowdich Order Homoptera Homoptera Homoptera Homoptera Homoptera Homoptera Homoptera Homoptera Thysanoptera Thysanoptera Acarina Orthoptera Lepidoptera Lepidoptera Lepidoptera Lepidoptera Lepidoptera Lepidoptera Lepidoptera Coleoptera Coleoptera Coleoptera Diptera Pulmonata Family Aphididae Aphididae Aphididae Aphididae Aphididae Diaspididae Aleyrodidae Cicadellidae Thripidae Thripidae Tetranychidae Acridiadae Noctuidae Noctuidae Noctuidae Unspecified Pyralidae Psychidae Noctuidae Meloidae Chrysomelidae Chrysomelidae Agromyzidae Achatinidae Destructive stage of the pest Adult & nymph Adult & nymph Adult & nymph Adult & nymph Adult & nymph Adult & nymph Adult & nymph Adult & nymph Adult & nymph Adult & nymph Adult & nymph Adult & nymph Larva Larva Larva Larva Larva Larva Larva Adult Adult Adult Maggot Adult 101 The Journal of Plant Protection Sciences, 1(1) : 98-101, 2009 Ta bl e 2 H os t r an ge , n at ur e of d am ag e, m od e of o cc ur re nc e an d st at us o f p es ts in fe st in g or na m en ta l p la nt s