December Flies

I have just been browsing the latest issue of Dipterists Digest, number 19/2. In it Pete Boardman, from the Field Studies Council Preston Montford Centre has written an article on records of flies in December in Shropshire. He had examined the Shropshire records and found that there were none since 1945. In December 2011 he set out to record flies to see how many species were about and counted 31 species and one that is causing some identification problems. I won't go into details but I was impressed by the number.

This made me wonder what the Northants position is. I have checked the records held by me and the Northants Biodiversity Records Centre and we start in a better position than Shropshire did, although we have a way to go to reach 31 species. Here is a brief summary. Only four record sets have been made in December since 1990. The most impressive list was of 9 species at Collyweston Quarry made by Pete Kirby. The other three species were single records made by me (2) in 2011 and an anonymous record of 1 species in 2001. This gives a grand total of 12 species recorded in December since 1990!

The species are:
Stratiomyidae:
     Pachygaster atra
Phoridae:
     Megaselia serrata
Syrphidae:
     Pipizella viduata
Tephtritidae:
     Chaetostomella cylindrica
     Rhagoletis alternata
     Terellia colon
     Urophora cardui
     Urophora jaceana 
Sciomyzidae:
     Pherbellia dubia
     Coremacera marginata
Muscidae:
     Eudasyphora cyanicolor
     Polietes lardarius (the only species we have in common with the Shropshire list!) 
 
It is not surprising that there are several Tephritid flies on the list as many of these overwinter as adults. They tend to stay hidden in dense foliage unless there is a particularly warm spell. Sweeping coarse herbs, especially the plants that they breed in, may turn up some more. I was surprised that so few Muscids were recorded, but I suppose this is down to there not being many people who want to, or can, identify these bristly beasties. Looking under loose bark or in dark corners indoors may reveal a few.

So if you are fed up with pre-Christmas shopping or need to have some post-Christmas exercise, how about trying to improve the list?