Diversity and foraging behaviour of syrphid flies on Brassica campestris L and Mangifera indica L

Abstract

Investigation on the diversity and foraging behaviour of syrphid flies on newlineBrassica campestris L. and Mangifera indica L. was carried out in the ICR Farm; newlineHorticulture Orchard, Department of Horticulture and Apiculture laboratory, newlineDepartment of Entomology, Assam Agricultural University, Jorhat during 2017-2018 newlineand 2018-2019. The insects forager complex of rapeseed consisted of 27 species newlinenamely Apis cerana, A. dorsata, Nomia sp., Stomorhina discolour, Episyrphus newlinebalteatus, Betasyrphus aeneifrons, Syrphus sp., Eristalinus arvorum, E. polychromata, newlineE. quinquestriatus, E. megacephalus, E. paria, Mesembrius quadrivittatus, Eristalis newlinetenax, Phytomia errans, Melonstoma orientale, Asarkina ericetorum, Sphaerophoria newlinesp., Dideopsis aegrota, Delias pasithoe, Micraspis discolor, Coccinella tranversalis, newlineChrysomya meghacephala, Musa domestica, Coccinella septempunctata, Syntomoides newlineimaon and Pieris rapae. Out of these Stomorhina discolour was recorded to be newlinemaximum (9.37%). Whereas, in mango all total 15 species namely Apis cerana, newlineA. dorsata, A. florea, Stomorhina discolour, Eristalinus arvorum, E. polychromata, newlineE. quinquestriatus, E. megacephalus, E. paria, Mesembrius quadrivittatus, Asarkina newlineericetorum, Chrysomya meghacephala, Musa domestica, Neptis cartica and Oecophylla newlinesmargdina were recorded. Out of these Eristalinus arvorum was recorded to be newlinemaximum (12.05%). The highest species diversity index of 2.59 was recorded from newlinerapeseed crop as compared to 2.03 from mango crop. The maximum total body length in newlineEristalinus arvorum (10.00 ± 0.52 mm) which was followed by E. polychromata (8.64 ± newline0.51mm) and minimum Mesembrius quadrivittatus (2.19 ± 0.60 mm), respectively. The newlineprincipal component analysis of 15 morphometric characters obtained from15 species of newlinesyrphids which explained 84.84 per cent variation among the species of syrphids. newlineWhereas, in the principal component 1, 15 morphometric characters were influencing newlineparameters with components loading from 0.985 to 0.280 that accounting for 76.32 per newlinecent of the variation