It has been suggested that the accumulated data in Bugguide can be put to use in a number of ways in the future, for instance in studies of populations, geographic distribution and phenology. Despite the lack of a coherent methodology in the gathering of data, such use may be possible and it may be possible sooner than expected. To test this hypothesis I used the Advanced Search to construct monthly charts of several bee genera.
I used the raw data. For a more advanced study it would be necessary to discard irrelevant images, such as empty nests, leaf damage, etc. It would also be preferable to use only one entry for each specimen rather than variable numbers depending on the number of images of the same individual. In many cases, only adults or immature stages would have to be selected. This didn’t seem necessary for the purpose of this work. Despite some possible "noise" in the data, certain patterns seem apparent.
The graphs include all the images of the respective genera submitted to Bugguide from its start in February 2004 to March 27, 2011.
Graph 1 illustrates the monthly numbers of images for two bee genera: Andrena
populations peak in April and May, while Megachile
are most numerous between June and September.
Graph 2 shows the monthly distributions of populations of Megachile
. The cuckoo bees of the genus Coelioxys
specialize on Megachile
bees. The rise and fall of their populations follow those of their hosts very closely and their numbers are smaller just as expected.
Graph 3 shows the phenology of Andrena
(blue), the cuckoo bee Nomada
(red) and the parasitic beefly Bombylius
(yellow). The populations of Nomada
follow those of Andrena
. The numbers of the two parasites are rather high when compared to those of Andrena
. If Andrena
were the only hosts of these parasitic bees and flies, they would not be able to sustain such large populations. However, Nomada
in addition to Andrena
as hosts in addition to Andrena
None of this is news; it just confirms other observations. In fact these charts can be compared to the ones developed by Sam Droege (The Weekly Phenology of Bees of the Mid-Atlantic States: MD, VA, WV, DC, PA, DE
) using collections from the USGS bee database. The results are similar.
It is nice to see how Bugguide data can be used. Its potential will grow in the future. It would also be possible for the advanced search to generate data sheets and charts like the ones presented here, instead of copying the numbers manually as I did for this little study.
Update, Dec.20/2016. Sam Droege has published newer Phenology of Bee Genera, Midatlantic States. USA.