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Subject: Entomology × Author: Makkar, Gurpreet Singh × End date: 2015 × Start date: 2015 × Type: Thesis × Thesis Type: Ph.D ×
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    Morphological and molecular characterization of regional crop pollinating bee fauna (Hymenoptera: Apoidea)
    (PAU, 2015) Makkar, Gurpreet Singh; Chhuneja, Pardeep Kumar
    Studies on ‘Morphological and molecular characterization of regional crop pollinating bee fauna (Hymenoptera: Apoidea)’ were conducted at Punjab Agricultural University, Ludhiana (India), during 2012-2014. Investigations were carried out on the relative abundance and diversity of the bee fauna on six bee floral crops (Brassica juncea, Brassica napus, Brassica rapa, Helianthus annuus, Trifolium alexandrinum and Cajanus cajan) in three agroclimatic zones of Punjab, morphological characterization of bee species based on 40 morphometric characters and molecular characterization of the bee fauna through DNA barcoding. In all, 17 bee species with complete DNA barcodes and morphometric characterization, comprising of 5 new species records: 1 in India, viz., Andrena agilissima, and 4 in Punjab, viz., Tetragonula iridipennis, Megachile anthracina, Megachile creusa and Megachile ramakrishnae, representing 7 genera, 5 subfamilies and 4 families of superfamily Apoidea were recorded. Apis mellifera was the most dominant (over the crops and zones except in C. cajan), with relative abundance ranging from 17.6 per cent on C. cajan to 26.5 per cent on T. alexandrinum. Megachile lanata and Megachile bicolor were the most abundant pollinators on C. cajan in all the three zones. The relative abundance of Apis species varied from 34.4 per cent on C. cajan to 77.8 per cent on T. alexandrinum. Thus, the relative abundance of non-Apis bees (social and solitary) revealed a substantial stake with minimum of 22.2 per cent on T. alexandrinum to the maximum of 65.6 per cent on C. cajan. The species richness was the highest (11) on B. juncea and B. napus, and the lowest (8) on T. alexandrinum. The species diversity, based on 12 diversity indices, was the highest in Sub-mountain Undulating zone followed by the Central Plain and Western zone. Temporal species diversity was higher at 1100 and 1400 h than at 0800 and 1700 h. The 40 morphological characteristics recorded for the 17 bee species revealed significant differences within and across the family groups, of which, thorax width, abdomen width, clypeus length, clypeus width, inter-orbital distance through antennal sockets, compound eye length, distance between antennal sockets, ocellocular distance, forewing length, jugovannal index, hind tibia length and hind basitarsus length revealed relatively higher discriminating ability among the species. DNA sequencing for the mitochondrial cytochrome c oxidase (cox1 or COI) gene was carried out for all the 17 bee species. The DNA barcodes were generated for all the 17 species and were submitted to BOLD (The Barcode of Life Data System). Phylogenetic relationships among the barcoded species were decoded with dendrogram based on mt COI gene sequences which grouped various operational taxonomic units (OTUs) based on evolutionary relationship among themselves. The present study is pioneering work in the country having succeeded in decoding the crop and region specific species diversity, species taxonomy and phylogenetics achieved through combined strengths of traditional taxonomy and DNA barcoding techniques. The information generated on the regional and crop specific species richness, abundance, diversity and DNA sequences of bee fauna would serve as baseline data, facilitating as a potential identification tool for further accounting of bee diversity, for ecological studies of bee communities, documenting shifts or declines in the species composition, and initiating their habitat management programmes.