wherefore and wither the yellow pan trap?
An 18 oz. yellow SoloGripsTM bowl (model SGB18 0100) glistening in the sunshine.
Since moving to Raleigh just over a year ago I've noticed a marked decrease in my ability to find plastic yellow bowls, especially my two favorite models from the Solo® Cup Company: the 12 oz. PSB2Y 0099 and the 18 oz. SGB18 0100. Why would anyone care about something so insignificant as a yellow, disposable picnic bowl? Because this happens to be the most sophisticated and successful tool for collecting parasitic Hymenoptera! These little bowls, supplied with the right medium and positioned in the proper habitat, vastly outperform any other collecting technique - sweep net, Malaise trap, Winkler extractor, Berlese funnel, pitfall trap, etc. - when it comes to the myriad parasitoid wasps that many of us care about.
So what's so special about Raleigh? Nothing, really, when it comes to yellow bowls. This is a nation-wide phenomenon. It appears that Solo® has dropped the yellow bowls to focus on producing blue and red bowls instead. These colors are still good for stephanid wasps and bees (Anthophila), but not the chalcidoids, proctotrupoids, and ceraphronoids we need to collect. Until Solo® re-engages their production these little yellow bowls will be worth their weight in gold. Let us know if you come across a stash somewhere(!) or if you've found a comparable model made by another company.
A line of SGB18 0100s - the workhorse of the pan trap world - pulling in a diverse array of Costa Rican insects.
Collecting insects in yellow pans - a brief introduction:
- Prepare/mix your collecting medium in a large jug or series of bottles: water, biodegradable dishwasher detergent (maybe a teaspoon per gallon of water), salt (enough to make the water as salty as seawater)
- Scatter a line of bowls in the habitat of interest. I like to begin and end my line with a double bowl (use your imagination here): 8oooooooooooooo8
- Fill each bowl about 1/3 of the way with the collecting medium.
- Sit back with your favorite beverage and watch beautiful insects amass in your golden vessels.
- Try to collect the insects within 48 hours (better if out for <12 hours). Pass the contents of each bowl through fine mesh. I use a cross-stitch frame to keep it taut, but one could also use a fine aquarium net. Be sure to capture the collecting medium for proper disposal.
- Rinse your mass of collected insects so that all the soap is washed off.
- Drop the mass into alcohol to sort later.
This seems about par for the course. We had it with mosaic green tiles, a standard for collecting aphids, with a spectrum similar to a green leaf so as to be neutral in measuring landing rates. Somehow, we need to let these companies know that their products are important to our science so that they might warn us when green tiles go out of fashion or yellow bowls are not the color of the day! These standardized collecting methods are important for making comparisons.
Posted by Gail on September 18, 2008 at 09:29 PM EDT #
Hi Gail,
Maybe you should wander over to Solo in Urbana and plead our case! We'll you give you the data you need to make a strong argument. Or we could have a sit-in and drum circle on their lawn...
Andy
Posted by ardeans on September 18, 2008 at 10:33 PM EDT #
Dear Andy
We have faced the same problem in Norway. I even contacted the company that imports these bowls. White, blue and red are still available here, but not yellow. The big plates are still available in yellow. The company told me that new colors are coming - pink and black. Anyway, we bought many white bowls and went to the paint shop and bought some yellow spray paint and sprayed the center of the bowls. This worked perfectly, and it seemed that this collected more than my old yellow bowls. The insects are not so interested in the sides of the bowl, but insstead they drop directly in the midle at once.
Lars Ove
Posted by Lars Ove Hansen on September 19, 2008 at 04:20 AM EDT #
Ah ha! A worldwide phenomenon. While I have never painted pans myself, I have plenty of colleagues that work with paint. One advantage is that you can get a uniform, precise color; the manufactured pans always seem to range slightly between yellows, depending on the day they were made. I love the idea of mixing colors. Your yellow spot in the middle of a white pan might do a better job of mimicking flowers. We'll have to give it a try...
Posted by ardeans on September 19, 2008 at 11:08 AM EDT #
With any trapping system, you need to double check not what the Pantone or other system may tell you, but what a spectrophotometer tells you not only about the yellow you see, but the other wavelengths that may also be active. For us, painting was a poor second to tiles, but we had the mission of trying to mimic a leaf's profile. What we see is not always what will be attractive or active in the larger spectrum. Yellow is almost always an attractant, and if this is your goal, you will still probably find that not all yellows are created equally with respect to the numbers and taxa that are attracted.
Posted by Gail on September 19, 2008 at 09:44 PM EDT #
I have a stash of yellow Solo bowls myself that I am watching slowly shrink. I have had good luck with pans spray painted with florescent yellow spray paint. The problem, as you mentioned, is that now even white bowls that can be painted are hard to find.
I would suggest that you try using the small fishnets made for tropical fish to collect the insects from the pan traps. The green ones have too large a mesh to be used, but look for the ones with the white bags. They have a much finer mesh that works very well.
Posted by Steve Heydon on September 23, 2008 at 12:32 PM EDT #