Time filter

Source Type

Nath S.,Bidhannagar Government College | Rai A.,Darjeeling Government College | Bhattacharya S.,Darjeeling Government College | Saha A.,Darjeeling Government College
Journal of Asia-Pacific Entomology | Year: 2010

Population dynamics of five different species of grasshopper were analyzed for the first time in Darjeeling (Lebong and Happy Valley) of the eastern Himalayan region of India. The study is based on the relationship between monthly samples collected using sweep nets for three years (March, 2005 to February, 2008) in relation to meteorological parameters (monthly average rainfall, monthly mean maximum and minimum temperatures). The population for each of the five species of grasshopper is plotted against the Aridity Ratio (A.R.). For all species, the population increases at lower A.R. values and then decreases exponentially at higher A.R. values. The exponentially decreasing part of the population is modeled using a simple formula. The monthly population of A. crenulata nymphs and adults in Lebong has also been modeled by iterative equations using A.R. and results compared satisfactorily with the sample data. These works show the possibility of forecasting grasshopper populations using a simple model and thereby easing the regulation process. © 2010 Korean Society of Applied Entomology, Taiwan Entomological Society and Malaysian Plant Protection Society. Source

Nath S.,Bidhannagar Government College | Anand H.,Bidhannagar Government College | Anand H.,Visva Bharati University | Haldar P.,Bidhannagar Government College | Haldar P.,Visva Bharati University
Journal of Entomological Research | Year: 2011

The level of different heavy metals(Pb, Cd, Cr, Zn, Cu) was studied on the consumers [four species of acridid grasshoppers: Acrida exaltate (Walker), Oedaleus abruptus (Thunb.), Pyrgomorpha concica (Oliva.) and Cyrtacanthacris tatarica (Linn.)] in highly polluted industrial area of Durgapur and non industrial area of Santiniketan, West Bengal, India. Pb accumulation was high in all the four species of grasshoppers than other metals in the industrial area but was absent in non industrial area. Significantly higher concentrations of Pb in Acrida exaltata (Walk.) proved this species to be a comparatively better accumulator of Pb and can play an important role in biotransfer of Pb to higher trophic level. Source

Manna S.,West Bengal Biodiversity Board | Ghara T.K.,Bidhannagar Government College | Ray D.,West Bengal Biodiversity Board | Roy A.,West Bengal Biodiversity Board
EurAsian Journal of BioSciences | Year: 2013

Background: Traditionally managed sacred groves in the lateritic parts of eastern India are a common phenomenon. Groves located in the transitional ecosystem are characteristically rich in biodiversity and are found to be showcasing local refuges. Besides the cultural and aesthetic needs of mankind, these ancient forest remnants are the center of attraction to the researchers for their immense veritable gene pool thriving on sacred belief. Present study highlights the phytosociological characteristics along with the way of traditional management of a sacred grove. Method: Traditional management practices were observed from the local community. Plants were identified following standard literature. Nature of relationship between different climbers and lianas with the major tree species of the grove was studied through cluster analysis, based on percentage cover data of each of the major climbers and lianas on the host trees. Results: Syzygium cumini, Shorea robusta and Terminalia arjuna contributed most to the architecture built up of the grove. Out of 12 major species of climbers and lianas, Derris scandens showed its maximum abundance in terms of canopy coverage throughout the grove followed by Tinospora cordifolia and Gouania tiliaefolia. Certain degree of positive correlation was observed between different climbers and lianas with the mean height and mean diameter at breast height of the major tree species. Conclusions: High species richness, confinement of the species and less undergrowth are the key characteristics of a sacred grove in transitional ecosystem. Opportunistic and aggressive nature of spreading have rendered Derris scandens, Tinospora cordifolia and Gouania tiliaefolia fittest in these highly overlapping niches of the grove. Adaptive management involving the local folk may help the Government in formulating the conservation strategies especially in non forest areas. © EurAsian Journal of BioSciences. Source

Discover hidden collaborations