Counting the total number of pests on a sticky tap is unnecessary. All that’s really needed is a representative number to indicate the developmental direction of the pest population in question — is it going up, going down, or remaining stable? Obtaining a representative count instead of a total count is especially important in a larger operation where there are hundreds of traps. But how do we get this representative number? The answer is simple: count only part of the trap. A square inch of trap surface is all that’s needed, provided the one-inch represents the average distribution of pests on the trap in question.
You may immediately wonder why we just don’t use one-inch square sticky traps, and it’s a valid question. The simple answer is a 3×5 trap is larger, more attractive surface. While smaller traps may be effective is some micro situations, in a typical greenhouse they’d probably end up lost in the shuffle.
Gridded traps may be a solution for some folks, though we have found the supply of these sporadic at best in past times. Presently we can source these from Seabright Labs — but we haven’t worked with them ourselves. We may at some point if there’s a demand. We’re not sure. In the past, with other manufacturers’ gridded traps, we’d heard complaints about the lines interfering with the counts, also that the traps are made of paper instead of plastic and had a tendency to deteriorate before the natural life of the sticky goo ended. The feedback we’d heard we have to take with a grain of salt for by no means did we hear a lot of it. We wouldn’t expect the traps to be suitable to all even if they were perfect.
Another solution is to use less expensive conventional yellow traps and make a trap counting card. This card would be made of plastic of sticky trap thickness and stiffness as a minimum. In said card you’d cut a one-inch square opening. Gently holding this counting card over your traps will offer you a condensed counting area. If you are feeling clever, you could probably fix a hand lens over the card to make the tool that much more useful.
To learn more about scouting specifics, please read our Scouting Information and Scouting Plan pages in our Necessary Info section.
