Henry et al. (Reports, 20 April, p. 348) used a model to predict that colony collapse in honey bees could be precipitated by pesticide-induced intoxication that disrupts navigation. Here, we show that collapse disappears when the model is recalculated with parameter values appropriate to the season when most pesticide-treated flowering crops bloom.

J E CRESSWELL

H M THOMPSON

Fulltext

University of Calcutta (informally known as Calcutta University or CU) is a collegiate public state university located in Kolkata, West Bengal, India.&nbsp;Within India it is recognized as a &quot;Five-Star University&quot; and accredited &quot;A&quot; Grade by National Assessment and Accreditation Council.

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The University of Calcutta has secured the Fifth position among the Universities of India in the prestigious &quot;Indian University Ranking 2019&quot; list, released by the NIRF of the Ministry of Human Resource Development, Government of India.

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It was established on 24 January 1857, and was one of the first institutions in Asia to be established as a multidisciplinary and Western-style university. Its alumni and faculty include several heads of state, heads of government, social reformers, prominent artists, only academy award winner and Dirac medal winner in India, many Fellows of the Royal Society and five Nobel laureates as of 2019 which is highest in South Asia.

University Of Calcutta

Science

Currently, there is concern about declining bee populations and some blame the residues of neonicotinoid pesticides in the nectar and pollen of treated crops. Bumble bees are important wild pollinators that are widely exposed to dietary neonicotinoids by foraging in agricultural environments. In the laboratory, we tested the effect of a pulsed exposure (14 days 'on dose' followed by 14 days 'off dose') to a common neonicotinoid, imidacloprid, on the amount of brood (number of eggs and larvae) produced by Bombus terrestris L. bumble bees in small, standardised experimental colonies (a queen and four adult workers). During the initial 'on dose' period we observed a dose-dependent repression of brood production in colonies, with productivity decreasing as dosage increased up to 98 μg kg-1 dietary imidacloprid. During the following 'off dose' period, colonies showed a dose-dependent recuperation such that total brood production during the 28-day pulsed exposure was not correlated with imidacloprid up to 98 μg kg-1. Our findings raise further concern about the threat to wild bumble bees from neonicotinoids, but they also indicate some resilience to a pulsed exposure, such as that arising from the transient bloom of a treated mass-flowering crop. © 2013 Laycock, Cresswell.

PLoS ONE

Repression and recuperation of brood production in Bombus terrestris bumble bees exposed to a pulse of the neonicotinoid pesticide imidacloprid

Ecotoxicology

Neonicotinoids in bees: a review on concentrations, side-effects and risk assessment

A Quantitative Model of Honey Bee Colony Population Dynamics

A meta-analysis of experiments testing the effects of a neonicotinoid insecticide (imidacloprid) on honey bees

Experimental Gerontology

Honey bee (Apis mellifera) workers live longer in small than in large colonies

Pest Management Science

Applied aspects of neonicotinoid uses in crop protection

Comment on "a common pesticide decreases foraging success and survival in honey bees"

Journal	Data powered by TypesetScience
Publisher	Data powered by TypesetAmerican Association for the Advancement of Science
ISSN	0036-8075
Open Access	Yes