March 2012 Newsletter (vol.5)   >>   A Sticky Situation

Pestrap Sticky Trap Photo


IPM is not a new strategy, although it seems to be gaining momentum with the increasing demand for organically grown plants and produce. IPM: Integrated Pest Management is a sustainable approach to managing pests that begins with scouting or monitoring the pest populations.  The purpose of this step is to detect the presence, concentration, and type of pests to enable you to make more informed and timely control decisions. No better way to detect pest populations than by using pestraps™, aka sticky cards or glue traps. But so many questions arise when considering the use of pestraps like: how many do you use for your greenhouse, what color is best, and where should they be placed?  This article will answer any questions you may have about using pestraps in your greenhouse.

What will they catch?
It is important to note that pestraps should not replace plant inspection because they will only trap the flying insect populations; therefore, mites, mealybugs, scales, wingless aphids, immature thrips, and immature whiteflies will not be caught on the traps.  So you ask, “What will the traps catch?”  The pestraps will catch winged aphids (which usually develop when there is a high infestation), leafminer adults, mature thrips, mature white flies, fungus gnats, shore flies, as well as many others.

Color & Size:
Pestraps are available in two different colors and three different sizes.  Which choice is best for your situation, depends upon which insect you would like to monitor.  Yellow is a good choice for general pest monitoring. It will attract the majority of the insects while Western Flower Thrips (WFT) and shoreflies prefer the blue.  An easy solution if you would like to monitor all insects is to use the double sided yellow and blue pestraps.  In regards to the size, it is completely your choice.  The 3” x 5” and 4” x 10” mid-size pestraps are great for monitoring while the 10” x 16” jumbo size is best used for mass trapping.

Placement of Pestraps:
Place the traps at or just above plant height and adjust the height as your crop grows.  This is where most of the flight activity will occur, but we have found that fungus gnats, shore flies, thrips, and leafminers can also be trapped effectively just above the soil.  Also be sure to place some traps near side vents, doors and known susceptible plant varieties.  The recommend number of pestraps to effectively monitor insect populations is 3-4 per 1000 square feet.   Most of the time you should position the pestraps vertically unless otherwise stated. If you are attempting to monitor shoreflies or fungus gnats then it is recommended to position them horizontally.  It also may be helpful in February to place pestrap cards just above the floor level to detect any early emerging thrips that have overwintered in your greenhouse dirt or gravel.   Important side note: if you are using beneficial insects with a winged stage, you may want to consider using fewer pestraps so they are not all trapped.

Changing Frequency:
The pestraps should be checked and replaced on a weekly basis. The cards will lose effectiveness, stickiness, when coated with debris.  When temperatures increase check the cards twice a week, and during the winter months you may not need them at all or quite as many.  The 4” x 10” and 3” x 5” sizes both have grids on the cards to assist in counting the insect populations. Identifying the insects that you catch may be a bit tricky until you become familiar with the different types. It is easier to identify them using a hand lens for magnification of 10x-15x. 
Hopefully we have cleared up any confusion about how to use pestraps as part of your IPM strategy, but if you still have any questions do not hesitate to contact our sales department.  Once you get in a routine of monitoring your pest populations it will be much easier to make effective applications to keep them under control.

Additional pestrap accessories: