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
"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
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 Http://www.pwrc.usgs.gov
Had I not seen the Sun
I could have borne the shade
But Light a newer Wilderness
My Wilderness has made -
- Emily Dickinson
Bees are not optional.
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