AgreenSkills session, year: 1st session, 2015
Receiving laboratory: AE Bees and the Environment Research Unit PACA, Avignon
Country of origin : Canada
Effects of pollen-bound pesticide mixtures on honeybee behavior
Beneficial arthropods can exhibit a wide variety of physiological and behavioral alterations following the exposure to a single pesticide. Yet, we know a lot less about the chronic exposure to the common pesticide mixtures that are present in agricultural fields. In this study we identified common pesticide mixtures consisting of 4-5 molecules used as insecticides, fungicides or herbicides that are present in pollen gathered by honeybees in France. Five mixtures were chosen based on pesticide co-occurrence and their negative correlation with the amount of brood present in hives surveyed by the Observatoire de Residus des Pesticides. These five mixtures were tested on experimental groups of newly emerged bees that ingested the contaminated pollen for 6 days. Bees were tagged with a barcode and their activity was followed using optical counters at the hive entrance. Our results show that two of the experimental mixtures consisting of 3-4 fungicides and 1 insecticide changed significantly honeybee flight activity. Bees exposed to these two pesticide mixtures make fewer and shorter flights. The gradual increase in outside activity during the adult worker ontogeny is slowed down by these two pesticide mixtures. The age at which exposed bees start foraging is delayed by 2 days. Due to the strong relationship between the age of the onset of foraging and bee longevity, exposed bees start foraging later in life, spend less time outside and hence live longer than control bees. Exposed bees manage to perform the same number of flights and spend as much time outside the hives as control bees but require a considerable amount of extra time (≈6 days) to do so. Furthermore, one of the pesticide mixtures identified hampers pollen foraging efficiency; exposed bees are not able to carry the amounts of pollen that control bees do. In conclusion, two pesticide mixtures that are commonly found in pollen in France disturb honeybee flight activity, and one of these mixtures prevents bees from efficiently foraging on pollen. The potential effects of the observed slow-down in outside activity, increased longevity, and reduced foraging efficiency to the overall colony status are currently unknown. We have currently started experimental and modelling approaches to address this question. Future studies should also aim at untangling the mechanisms and the consequences of the behavioral shift caused by these two pesticide mixtures. Finally, the use of optical counters at the hive entrance provides information on the cryptic or subtle effects of pesticides.
Alberto Prado Farías is a Mexican biologist interested in plant and insect physiology. Prado received his bachelor degree in Biology from the Universidad Autónoma de Querétaro, México in 2008 and his Ph.D. in Plant Science McGill University in 2014. His PhD thesis focused on the chemical ecology of cycads and their associated insects. He has worked on a variety of plant and insect taxa including cacti, cycads, sedges, beetles, butterflies and bees. One of his main areas of research is how toxins move through the environment.
*Prado, A., Rubio-Méndez, G, Yañez-Espinosa, L. & Bede J. 2016. Ontogenetic changes in azoxyglycoside levels in the leaves of Dioon edule Lindl. Journal of Chemical Ecology 42:1142–1150.
Prado A., Cervantes-Díaz, F., Perez-Zavala, F.G., González-Astorga, J., Bede, J. & Cibrián-Jaramillo, A. (2016) Transcriptome-derived microsatellite markers for Dioon (Zamiaceae) cycad species. Applications in Plant Sciences 4(2).
Waterway M.J., Martins, K.T., Dabros, A., Prado. A., Lechowicz, MJ. (2016) Ecological and evolutionary diversification within the genus Carex (Cyperaceae): Consequences for community assembly in subarctic fens. Systematic Botany 41(3): 558-579.
*Prado, A., Sierra, A., Windsor, D. & Bede J.C. 2014. Leaf traits and herbivory in a tropical gymnosperm, Zamia stevensonii (Zamiaceae). American Journal of Botany 101: 437-447.
Paudel, J., Copley, T., Amirizian, A., Prado, A., & Bede, J.C. 2013. Arabidopsis redox status in response to caterpillar herbivory. Frontiers in Plant Science 4: 113.
Prado, A., McKenna, D.D. & Windsor, D. 2012. Molecular evidence of cycad seed predation by immature Aulacoscelidinae (Coleoptera: Orsodacnidae). Systematic Entomology 37: 747-757.
*Prado, A., Ledezma, J., Cubilla-Ríos, L., Bede, J.C. & Windsor, D. 2011. Two genera of Aulacoscelinae beetles reflexively bleed azoxyglycosides found in their host cycads. Journal of Chemical Ecology 37: 736-740.
Yesson, C., Bárcenas, R.T., Hernández, H.M., Ruiz-Maqueda, M.L., Prado, A., Rodríguez, V.M. & Hawkins, J.A. 2011. DNA barcodes for Mexican Cactaceae, plants under pressure from wild collecting. Molecular Ecology Resources 11: 775-783.
*Thivierge, K., Prado, A., Driscoll, B.T., Bonneil, E., Thibault, P. & Bede, J.C. 2010. Caterpillar-and salivary-specific modification of plant proteins. Journal of Proteome Research 9: 5887-5895.
Prado, A., Hawkins, J.A., Yesson, C. & Barcenas, R.T. 2010. Multiple diversity measures to identify complementary conservation areas for the Baja California peninsular cacti. Biological Conservation 143: 1510-1520.
International Society of Chemical Ecology – Student Travel Award 2014
FQRNT Merit Scholarship for foreign student 2012-2014
Smithsonian Tropical Research Institute Travel Award 2011
Inter-American Institute for Cooperation on Agriculture (IICA) Fellowship 2011
Mexican Nationasl Science Council Doctoral Scholarship (CONACYT)