[Pollinator] Request for info about Digger Bees

[Matthew Shepherd (Xerces Society)]

Ooops, I typed this yesterday and then this morning realized that by hitting the "reply" button I had only sent it to Kim. So, here's my second attempt to post a response to Carol's question... 

Hi Carol,

It's difficult to answer this question without knowing more specifically which digger bees are because there are several genera of bees from several families that might be called that. 

In springtime, the ground nesting bees that are most frequently noticed or encountered are the mining bees (genus Andrena) that nest in lawns. (In Britain, they are so regularly found in gardens that they are often called "lawn bees".) They make it into the gardening columns of newspapers almost as often as carpenter bees. These bees are communal nesters and may nest in densities of 30 or more per square foot. I've seen nesting aggregations of 45,000 -- very cool! Andrena prefer sandy soils and each nest entrance is marked by a small mound of soil. Andrena bees offer no hazard to people; their stinger is too weak to penetrate skin. (Except in delicate areas. So, for example, try not to put them close to you nose to smell their mandibular glands; the tip of your nose has very thin skin!) Andrena are often active earlier in the spring than many other bees

There are also increasing numbers of polyester bees (genus Colletes) that are digging nests at this time. A couple of other big, obvious digger bees are Centris and Anthophora, handsome beasties about the size of a honey bee, but they may not be active just yet; late spring is the start of their season in many regions. If you have a large aggregation (you have signs up which suggests it is a pretty obvious and active nest site), it may not be any of these as I don't think they nest in such large numbers as Andrena.

Some of the information sheets put out by various state extension services are pretty good. A Google search for bee genera will throw up many of them. You'll also get lots of websites for pest control company's most of which recommend treating the lawn to remove them! The University of Florida's Featured Creatures fact sheets are normally good.

A few thoughts. I'm sure the Smithsonian's entomologists will have the answers you want.

Matthew

*********** REPLY SEPARATOR  ***********

On 5/8/2006 at 12:21 PM Kimberly Winter wrote:

>>From NAPPC partner Carol DiSalvo (National Park Service):
>
>"There seems to be an increase in the occurrance of digger bees in this
>[DC] 
>area.  I imagine this is a natural cyclic event.
>
>I am waiting to hear from Smithsonian entomologists but was wondering if 
>anyone has any info on any stings associated with this species ?
>
>We are currently signing the area to inform people that these insects are 
>not aggressive, are active as they are seeking mates, defending
>territories 
>and collecting pollen for larvae.
>
>Does anyone have any other outreach items prepared for digger bees?"
>
>Carol
>
>Carol_DiSalvo at nps.gov
>
>
>
>
>~Kim
>
>Kimberly Winter, Ph.D.
>International Coordinator
>North American Pollinator Protection Campaign
>E-mail: NAPPCoordinator at hotmail.com
>Internet: www.nappc.org
>Ph: (301) 219-7030
>
>Mailing Address:
>0105"B" Cole Student Activities Bldg
>University of Maryland
>College Park, MD 20742-1026
>
>
>_______________________________________________
>Pollinator mailing list
>Pollinator at lists.sonic.net
>http://lists.sonic.net/mailman/listinfo/pollinator


______________________________________________________
The Xerces Society for Invertebrate Conservation
Protecting wildlife through science-based advocacy, education, 
and conservation projects since 1971. To join the Society, make a 
contribution, or read about our work, please visit www.xerces.org.

Matthew Shepherd
Director, Pollinator Conservation Program
4828 SE Hawthorne Boulevard, Portland, OR 97215, USA
Tel: 503-232 6639 Fax: 503-233 6794
Email: mdshepherd at xerces.org 
______________________________________________________