Seminar "Pesticide imposed impairments on native Indian honey bees along an agricultural intensification gradient " by Dr. Priyadarshini Basu

Dear All,

Ecology and Evolution (Mikheyev) Unit would like to invite you to a seminar by Dr. Priyadarshini Basu.

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Date: Monday, April 11th, 2016\
Time:14:00-15:00
Venue: Seminar Room C016, Lab1
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Speaker: Dr. Priyadarshini Basu, University of Calcutta

Title: " Pesticide imposed impairments on native Indian honey bees along an agricultural intensification gradient ". 

Abstract:

Honey bees play an important role as pollinators in global cropping systems. In recent
decades, intensive agricultural practices have led to increased pesticide use, resulting in a
significant reduction in wild bees and other beneficial insects. An information gap led to the
present study being focused on the responses of the natural populations of native honey bees
to pesticide laden environment in agricultural landscape and their responses to field realistic
doses of pesticides in the laboratory. Analyses of morphological traits, behavioural traits,
physiological traits and genetic diversity have revealed distinct differences in populations
surviving in high and low pesticide zones along an agricultural intensification gradient. A
significant upregulation of three oxidative stress biomarkers – superoxide dismutase, catalase
and xanthine oxidase – was observed in both treated individuals in laboratory experiments
and also the field populations of Apis cerana and Apis dorsata sampled from pesticide use
gradient. This study also highlights the detrimental effects of pesticides on honey bee
olfaction and visual ability through behavioural studies. Honeybees from pesticide intensive
agricultural landscapes had impaired olfaction (evidenced by reduced proboscis extension
response) and visual ability (evidenced by colour choice experiments). Scanning electron
microscopic imaging of antennal sensillae and confocal microscopic studies of honey bee
brains for calcium ions on Apis cerana along with changes in expression of Calpain 1, an
important calcium handling protein playing a role in honey bee memory formation, were also
performed. Controlled laboratory experiments corroborated these findings. The genetic
diversity of the wild Apis cerana populations exposed to pesticides was also checked with
respect to the control populations both at protein and DNA levels. α – Esterase and glucose –
6 – phosphate dehydrogenase enzymes showed higher number of polymorphic bands in the
pesticide exposed populations. The bands obtained from Random Amplified Polymorphic
DNA (RAPD) technique using 3 random primers also showed a similar result where the
pesticide exposed populations exhibited more number of bands with higher polymorphism.

We hope to see many of you at the seminar.

Sincerely,
Yoko Fujitomi
Ecology and Evolution (Mikheyev) Unit