Color Trap Preferences of Late Spring Bees from Calvert County, Maryland, U.S.A. 8600 bees can't be wrong
The parasitic Hymenoptera USDA group ran a study of color preferences of Hymenoptera in bowl traps a couple of springs ago. They gave me the 8600 bees from that study and I have summarized the results below and in an associated Excel file. We are going to be jointly publishing that work hopefully sometime soon. Lots of interesting things going on regarding changes across the month of the study as well as site preferences. Presented here are just the common species. Overall there was something around 100 species of bees detected which, amazingly, is more than a quarter of the state's known bees. If you did a little back of the envelope scratching it seems quite possible that running this small number of bowls in this small area all year long could have yielded 50,000 bees and who knows what fraction of the whole bee fauna would have been incorporated. What do you know about your local bees?
Below is a description of the results taken from the Excel file....check the file out .... we have included in the file some fun mini-pie charts for each species that I particularly like.
"Based on data taken in 2007 from the Smithsonian USDA ARS Parasitic Hymenoptera Group's study of color bowl trap preference in Hymenoptera. Bowls were placed in 16 circles with 3 bowls of each color in each circle, bowls were randomly placed. Bowls were run continuously for the entire month of May with material collected every 2nd day. Location was a wide powerline right-of-way running through an upland deciduous forest (with swamps and fields nearby) in northern Calvert County, Maryland, U.S.A. near the Chesapeake Bay . The data here are for species which occurred 10 or more times. If not mentioned then the sex is female. Note that the florescent yellow bowls had only one coat of paint rather than the usual two and had significant fading over the coarse of the study. Highest or tied highest counts for a species/sex combinations occurred with the following colors: 19 white, 4 blue, 7 florescent blue, 20 yellow, 10 florescent yellow, 0 red, 0 clear. "
In a practical sense this is again pretty clear evidence that one needs a blue, yellow, and white component for trap surveys.
Sam Droege sdroege@...
w 301-497-5840 h 301-390-7759 fax 301-497-5624
USGS Patuxent Wildlife Research Center
BARC-EAST, BLDG 308, RM 124 10300 Balt. Ave., Beltsville, MD 20705
Had I not seen the Sun
I could have borne the shade
But Light a newer Wilderness
My Wilderness has made -
- Emily Dickinson
P Bees are not optional.