DOI: 10.5061/dryad.4df64
title: Data from: Interaction between Varroa destructor and imidacloprid reduces flight capacity of honeybees

description: Current high losses of honey bees seriously threaten crop pollination.
 Whereas parasite exposure is acknowledged as an important cause of these
 losses, the role of insecticides is controversial. Parasites and
 neonicotinoid insecticides reduce homing success of foragers, e.g., by
 reduced orientation, but it is unknown whether they negatively affect
 flight capacity. We investigated how exposing colonies to the parasitic
 mite Varroa destructor and the neonicotinoid insecticide imidacloprid
 affect flight capacity of foragers. Flight distance, time and speed of
 foragers were measured in flight mills to assess the relative and
 interactive effects of high V. destructor load and a field-realistic,
 chronic sub-lethal dose of imidacloprid. Foragers from colonies exposed to
 high levels of V. destructor flew shorter distances, with a larger effect
 when also exposed to imidacloprid. Bee body mass partly explained our
 results as bees were heavier when exposed to these stressors, possibly due
 to an earlier onset of foraging. Our findings contribute to understanding
 of interacting stressors that can explain colony losses. Reduced flight
 capacity decreases the food-collecting ability of honey bees and may
 hamper the use of precocious foraging as a coping mechanism during colony
 (nutritional) stress. Ineffective coping mechanisms may lead to
 destructive cascading effects and subsequent colony collapse.
description: Flight performance
 2015-11-13BeeNr: ID individual;
 Colony: ID colony; Molaire: 1 or 2M sugar concentration fed as fuel for
 flight; Varroa: treatment 0= low infestation (treated with acaricide),
 treatment 1= high infestation (NOT treated with acaricide); Imidacloprid:
 treatment 0= control 0 microgram per Liter, treatment 1= 6 microgram per
 Liter imidacloprid a.i. (in 660ml sugarwater 50% per week); FlightDate:
 date of the flight(s); Flightday: day since start, first flight date;
 Flightmill: ID flightmill; N: number of rounds continuous flight;
 Distancem: Distance in meters; Log_Distancem: log10 Distance in meters;
 Flighttimemin: Flight time in minutes; Log_Flighttimemin: log10 Flight
 time in minutes; Averagems: Average speed in meters per second; Maxms:
 Maximum speed in meters per second; Weightmg: Weight of the bee in
 milligram after the flight(s); Winglengthmm: Winglength of front wing from
 the joint to tip in millimeter; Survivalapril14: survival of the colony in
 April 2014 0=alive, 1=dead;Mites
 2015-11-13Varroa: treatment 0= low
 infestation (treated with acaricide), treatment 1= high infestation (NOT
 treated with acaricide); Imidacloprid: treatment 0= control 0 microgram
 per Liter, treatment 1= 6 microgram per Liter imidacloprid a.i. (in 660ml
 sugarwater 50% per week); Colony: ID colony; Succes: 0=group that did not
 fly, 1=groep that did succesfully fly; numberofbees: Number of individuals
 that was tested; Mitesgrambees: Number of phoretic mites per gram bees in
 October 2013; LNmites: Natural log of (number of mites per gram bees +
 0.01);Weights and Wings
 2015-11-13BeeNr: ID individual;
 Colony: ID colony; Varroa: treatment 0= low infestation (treated with
 acaricide), treatment 1= high infestation (NOT treated with acaricide);
 Imidacloprid: treatment 0= control 0 microgram per Liter, treatment 1= 6
 microgram per Liter imidacloprid a.i. (in 660ml sugarwater 50% per week);
 Flightmill: ID flightmill; Weightmg: Weight of the bee in milligram after
 the flight(s); Abdomenmg: Weight of the bee's abdomen in milligram
 after the flight(s); Thoraxmg: Weight of the bee's thorax in
 milligram after the flight(s); Winglengthmm: Winglength of front wing from
 basicosta to tip in millimeter;Successful flights
 2015-11-13File contains the data
 for the Chi-square test on the comparison of the number of bees that
 successfully flew the first and second flight.