Effects of the Insect Growth Regulator, Novaluron on Immature Alfalfa Leafcutting Bees, Megachile rotundata

Thumbnail Image
Date
2011-04-08
Authors
Hodgson, Erin
Pitts-Singer, Theresa
Barbour, James
Major Professor
Advisor
Committee Member
Journal Title
Journal ISSN
Volume Title
Publisher
Authors
Person
Hodgson, Erin
Professor
Research Projects
Organizational Units
Organizational Unit
Entomology

The Department of Entomology seeks to teach the study of insects, their life-cycles, and the practicalities in dealing with them, for use in the fields of business, industry, education, and public health. The study of entomology can be applied towards evolution and ecological sciences, and insects’ relationships with other organisms & humans, or towards an agricultural or horticultural focus, focusing more on pest-control and management.

History
The Department of Entomology was founded in 1975 as a result of the division of the Department of Zoology and Entomology.

Related Units

Journal Issue
Is Version Of
Versions
Series
Department
Entomology
Abstract

Alfalfa leafcutting bees, Megachile rotundata F. (Hymenoptera: Megachilidae), are the most common pollinators of alfalfa in the Pacific Northwest. Reports from users of M. rotundata in Idaho, Utah and Colorado have indicated exceptionally poor bee return from fields treated with novaluron to control Lygus spp. Our goal was to evaluate novaluron toxicity to immature M. rotundata using two different possible mechanisms of exposure. One goal was to assess immature mortality via treating nectar-pollen provisions and adults with novaluron. Immature M. rotundata mortality in all novaluron provision dosing treatments was significantly higher than the water or blank controls, providing evidence that novaluron is toxic to progeny in nest cells. The mean cumulative frequency showed that more eggs and 1st–2nd instars died compared to older instars. Female M. rotundata nested similarly in field cages during the field cage experiment; however, there was greater immature mortality in cages where females were fed sugar-water + novaluron compared to sugar-water only. Although females provided adequate provisions, there was a low percentage of egg hatch and larval development when females ingested novaluron before mating and nesting. Novaluron was also present in egg provision of bees collecting resources from novaluron-sprayed plants. At least 84% of progeny died when the females were allowed to mate and nest 24 hours after a novaluron application. Novaluron could be contributing to poor bee return in alfalfa grown for seed. Timely insecticide applications to suppress Lygus spp. is an important consideration to improve ongoing bee health.

Comments

This article is from The Journal of Insect Science 11 (2011): 1–10, doi:10.1673/031.011.0143.

Description
Keywords
Citation
DOI
Subject Categories
Copyright
Sat Jan 01 00:00:00 UTC 2011
Collections