No abstract

Spiders are the Arthropod and belong to the Phylum: Arthropoda, Class: Arachnida, Order: Araneae. Spiders totally depend on predation of small insects and other animals and have important role in the structure of communities and food webs both as an individual numbers and as an energy consumer.. Hence, documentation of spiders gives information about biodiversity of ecosystem in a particular geographical area. Totally arthropods belonged to 14 orders and 85 Nos. of different families. To study the similarity between two groups in species, family and ordinal level is used Agglomerative Hierarchical Clustering (AHC). Principal Component Analysis (PCA) and Correspondence Analysis (CA) were evaluated to understand the arthropod population dynamics and habitat specific occurrence of spiders in different ecosystem Viz., Silvicultural, Horticultural and Agricultural ecosystem. To correlate the weather parameters with spider population we used Pearson correlation, regression line, Redundancy Analysis (RDA) and Canonical Coefficient Analysis (CCA). Correlation analysis showed arthropod population positively correlated to maximum and minimum temperature and evening relative humidity and negatively correlated to morning relative humidity and rainfall. The eigenvectors at generic level was found maximum in horticultural ecosystem (0.591) followed by silvicultural (0.581), maize (0.407), rice (0.329) and potato ecosystem (0.183) in factor (F1). The asymmetric CA row and column plot in generic level suggested that the genus Tylorida,, potato and horticultural ecosystems respectively. In case of weather perimeter with relation to arthropod population RDA showed that Arachnids families viz., Lycosidae, Thomisidae, Theridiidae, Tetraganthidae etc are closely associated with maximum temperature in silvicultural and horticultural ecosystems.

Submission of an original paper with copyright agreement and authorship responsibility.I (corresponding author) certify that I have participated sufficiently in the conception and design of this work and the analysis of the data (wherever applicable), as well as the writing of the manuscript, to take public responsibility for it. I believe the manuscript represents valid work. I have reviewed the final version of the manuscript and approve it for publication. Neither has the manuscript nor one with substantially similar content under my authorship been published nor is being considered for publication elsewhere, except as described in an attachment. Furthermore I attest that I shall produce the data upon which the manuscript is based for examination by the editors or their assignees, if requested.Thanking you.

Spiders are the Arthropod and belong to the Phylum: Arthropoda, Class: Arachnida, Order: Araneae. Their occurrence worldwide is about 30,000 species belonging to the 60 families. Totally 4023 arthropods were collected from Silvicultural, Horticultural and Agricultural ecosystem (Maize, Potato and Rice) which belonged to 14 orders and 85 Nos. of different families. Among the ecosystem maximum diversity found in Silvicultural followed by Horticultural and Agricultural ecosystem in terms of alpha diversity such as Shannon Wiener index Simpsons D, Species number, Margelef D, Equitability J, Berger Parker index, Maclntosch U, Brillouin level, Fisher Alpha, Q Statistic and beta diversity such as Whittaker Bw, Cody Bc, Routledge Br, Routledge Bi, Routledge Be and Wilson & Shmida Bt.

Several diseases invading the crop are the major constraints for limited brinjal production and productivity. The most destructive and important disease on brinjal are Brinjal leaf blight and fruit rot incited by the fungus, Phomopsis vexans (Sacc. & Syd.) Harter (Edgerton and Moreland, 1921). The fruit rot distinctively is the most destructive phase of disease which damages the fruit partially or completely in the field as well as during transit. On the fruits, the disease appears as minute sunken greyish spots with

A study was conducted to determine the effect of artificial diets on some of the important biological parameter of Helicoverpa armigera under laboratory condition at 25±1°C, 75±5% R.H. and 14 hr photoperiod. Four locally available pulses viz., chickpea, green gram, pea and black gram were used as treatments and compared with that of the natural diet as control i.e. chickpea leaves. Sixty larvae in each treatment were fed and studied. Results revealed that larval duration was found to be the minimum in larvae reared on chickpea based diet and longer on pea, green gram and black gram respectively and maximum on chickpea leaves. Overall, the fitness index was found highest on chickpea followed by pea, green gram, black gram, black gram and chickpea leaves. The study proved that chickpea based diet was the best for mass rearing of Helicoverpa armigera while pea based diet could also be used as substitute.

Background Cabbage butterfly, Pieris brassicae (Linnaeus) (Lepidoptera: Pieridae), is one of the most important pests of cabbage and other cruciferous crops and accounts for > 40% yield reduction in the crops. An investigation on the baseline susceptibility of P. brassicae to Bacillus thuringiensis (Bt) Cry toxins in Meghalaya was evaluated for future exploitation in Bt resistance monitoring. Two different Cry toxins, Bt Cry1C and Cry2Ab, were screened against 11 different field populations of P. brassicae from the state of Meghalaya. LC50 was evaluated based on the response of larval mortality of P. brassicae using the leaf-dip bioassay method. Results The baseline-susceptibility tests conducted on P. brassicae in 11 different field populations from Meghalaya revealed that Smit population strains seemed to show less tolerance to both the Bt Cry toxins (Cry1C and Cry2Ab). Compared to the Cry1C toxin, Cry2Ab was found more potent against P. brassicae. The median lethal concentrations, LC50 72 h, varied from 0.535 to 1.725 µg/ml for Cry2Ab and 0.546–1.803 µg/ml for Cry1C toxin. The screening using leaf-dip bioassay resulted in a tolerance ratio of 3.3-fold and 3.2-fold for Cry1C and Cry2Ab, respectively. The most tolerant strains of P. brassicae from Umiam and Pepbah regions were observed to show discriminating concentrations of 19.30 µg/ml for Cry1C and 24.03 µg/ml for Cry2Ab (LC99, 72 h). Conclusions The Cry2Ab toxin was found to be more virulent than Cry1C toxin for P. brassicae. Certain candidate discriminating concentrations for Cry1C and Cry2Ab can be used as benchmarks for future resistance monitoring of P. brassicae to Bt Cry toxins.