[Syrphidae] Yellow pan traps

[Chris Bergh]

Hello. To build a pan trap for catching aphidophagous syrphids, I glued a
white plastic funnel to the base of a white plastic tray used to hold
plastic plant pots (about 25 cm diameter). A wood dowel inserts into the
spout of the funnel and is inserted into the ground so that the tray sits
about 15 - 20 cm above the ground. The plastic trays were spray-painted
yellow prior to constructing the traps, using an interior-exterior, all
purpose paint. I've used a 1:9 ethylene glycol:water ratio plus a couple of
drops of detergent in the yellow trays, and so far have caught some
syrphids and other insects, although many fewer syrphids than others (since
Easter). The problem is now that the paint is beginning to peel off of the
inside of the tray, apparently because of the solution. Has anyone used
this approach and had this problem. What was your solution? Is there a
commercially available yellow pan that would solve this problem? Is the use
of the green ethylene glycol going to seriously affect the capture of
syrphids (the 1:9 solution is very light green but does change the color of
the trap bottom when viewed from above). Thanks for your feedback. - Chris
J. Christopher Bergh
Virginia Tech
Alson H. Smith, Jr. AREC
595 Laurel Grove Road
Winchester, VA 22602
Tel: (540) 869-2560 ext. 32
Fax: (540) 869-0862