U.S. flagAn official website of the United States government
                    Here's how you know **Official websites use .gov**
                            
                            A **.gov** website belongs to an official government organization in the United States.
 **Secure .gov websites use HTTPS**
                            
                            A **lock** (                            
                              A locked padlock                                                      
                            
                            ) or **https://** means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.


Menu Agricultural Research Service
						
                    U.S. DEPARTMENT OF AGRICULTURE
 Pollinating Insect-Biology, Management, Systematics Research: Logan, UT
 close



    Research

                    Research Projects
                                    Publications
                                    Collaborations
                                    News
                People

                    Staff Listing
                                    CareersSearch small
                    Search
            
            ARS Home
                                About ARS
                                Contact Us




ARS Home Pacific West Area Logan, Utah Pollinating Insect-Biology, Management, Systematics Research Research Publications at this Location





- ARS National Programs
- Search for a scientific manuscript
- Search for a research project
- ARS Software
- Programs and Projects
- Collaborations
- Subjects of Investigation
- Publications
- Bee Lab Main
- Bee Mail Shelter
- Bumble Bee Rearing Guide
- Blue Orchard Bee - Fact Sheet
- Blue Orchard Bee Rearing Guide
- Build a Nesting Block
- Gardening & Landscaping Practices for Nesting Native Bees
- Gardening for Native Bees in N. America
- Hang Tags for Flowers
- Ozone to Decontaminate Honey Bee Supers
- Pollen Traps
- Reed Nests
- Stick Nests
- Alfalfa Leafcutting Bee (ALCB)
- Blue Orchard Bee
- Bumble Bee
- Bumble Bee Utah Quickguide
- Bumble Bees of the Pacific Northwest
- Monitoring Bumble Bees in the Pacific Northwest
- Bumble Bees Western U.S. Guide
- U.S. National Pollinating Insects Collection
- What are Bees?
- Pollinator Of The Month
- Bee Lab Main

Title:   Author  item
                                            James, Rosalind
  Submitted to: Journal of Economic Entomology
                                    Publication Type: Peer Reviewed Journal
                                    Publication Acceptance Date: 2/16/2005
                                    Publication  Date: 8/1/2005
                                    Citation: James, R.R. 2005. Impact of disinfecting nesting boards on chalkbrood control in the alfalfa leafcutting bee. Journal of Economic Entomology. 98(4):1094-1100.Interpretive Summary: The alfalfa leafcutting bee has been used in large numbers to pollinate alfalfa seed crops since the 1960s. These bees are kept in nesting boards that are essentially a solid board with holes drilled or molded into them. However, bee reproduction has been greatly affected by chalkbrood, a larval disease caused by a fungus. In the U.S., attempts to control this disease have been fairly unsuccessful, but include removing the overwintering larvae from the nesting boards, and then disinfecting the boards with heat treatments or a fumigant before they are used again the next year. The problem is that many boards are made of polystyrene (so heat cannot be used), and very few fumigants are registered for this use. In this study, the effectiveness of heat and methyl bromide fumigation were compared to a new disinfection method, ozone exposure. Ozone did not kill many of the fungal spores in fumigation chambers, and did not reduce chalkbrood levels in the field. Methyl bromide and heat treatments did kill large numbers of spores, but did not reduce chalkbrood levels in the field. Surprisingly, new nesting boards (boards free of spores) also had the same amount of chalkbrood in the field as used (contaminated) boards. Disinfecting nesting material may be necessary for controlling chalkbrood, but it is not enough, in and of itself. Enough spores were present in the field from someplace other than the boards to keep infections levels high. I hypothesize that this source was the emerging female bees, but the source needs to be determined so that it can be targeted for control.
                                Technical Abstract: The alfalfa leafcutting bee (Megachile rotundata (Fab.)) is a solitary, cavity nesting bee that has been managed in large numbers to pollinate alfalfa seed crops since the 1960s. Propagation of these bees from one year to the next has been seriously hampered by chalkbrood, a larval disease caused by the fungus Ascosphaera aggregata Skou. In the U.S., attempts to control the disease have been fairly unsuccessful, but include removing nests from the nesting boards, and then disinfecting the boards with heat treatments or a fumigant. The problem is that many boards are made of polystyrene (so heat cannot be used), and very few fumigants are registered for this use. In this study, ozone was tested as a fumigant and compared with heat treatments and methyl bromide fumigation. Ozone was found to be inadequate for killing A. aggregata spores, and for reducing chalkbrood levels in the field. Methyl bromide and heat treatments did greatly reduce spore viability in the boards, but did not reduce chalkbrood levels in the field. Surprisingly, larvae in  new nesting boards (boards free of contamination) and chalkbrood infection levels were similar to those nesting in contaminated, used boards. Disinfecting nesting material may be necessary for controlling chalkbrood, but the results reported here are an indication that it is not sufficient in and of itself. Some other source of spores was present in the field that was greater than the effect of contamination from the boards. I hypothesize that this source was the emerging female bees, but the source needs to be determined so that it can be targeted for control.


Return to top


Connect with ARS Sign up


ARS Home
                            USDA.gov
                            Plain Writing
                            Policies & Links
                            Civil Rights Statements
                            FOIA
                            Accessibility Statement
                            Privacy Policy
                            Non-Discrimination Statement
                            Quality of Information
                            USA.gov
                            WhiteHouse.gov