The concept is simple; the gardener will never find pests if you don’t look for them. However, early detection is key to avoiding big problems. For example, in ideal conditions a few fungus gnats can turn into a real problem in as little as 3 weeks. This seems like a long time, but by the time you notice that it is a problem there are many thousand more eggs ready to hatch and, all the while, larvae have been nibbling on your micorrhizal fungi and root hairs.
Fungus gnats are relatively easy to detect and deal with, but other pests are very, very difficult to get in check once well established. Therefore, a home cultivator must be vigilant and actively seek out the little beasties early on. This is especially critical in organic living soil systems where we expect there to be bugs. Commercial facilities dedicate many hours of labor every day to scouting procedures. Here are a few methods of scouting that I use consistently in my home garden.
- Passive detection with sticky cards: Yellow sticky cards are great for helping you to detect problems early and are commonly available pretty much anywhere that has a garden center. Check the traps daily to see what you have caught and identify the bugs if possible. Make note of the number of bugs caught per day to determine if there is an escalating issue.
- Bang-boards: Just as it sounds, this is a small board that you place under your plant to catch any bugs dislodged when you ‘bang’ the plant. A tap-tap-tap on the stem will very often send at least a few buggers falling from the foliage to the board. It can be handy to have a board with a white and black side because some insects can be very light in color and hard to see on a white board.
- Actively look: Use plain eye-sight to look at several leaves per plant, every day. Examine the top of the leaf and the bottom. You’re looking for lack of vigor, damage, honeydewliquid form of insect excrement; bug poop More, frasssolid form of insect excrement; bug poop More, live insects, mold, and mildew primarily. A UV light can be handy for quickly spotting frasssolid form of insect excrement; bug poop More and honeydewliquid form of insect excrement; bug poop More (in a dark room).
- “Scope it:” The shortened way of saying that you should use a jeweler’s loupe or microscope to take a closer look for very tiny insects. 30x magnification should be all you need in most cases. As I defoliate the underside of my canopy, I’ll often scope those leaves (especially the bottom) to look for pests.
Having an insect aspirator on hand can be a great way of capturing insects for identification purposes. You can keep specimens in alcohol if you are so inclined.
Finally, even though you may have active control measures in place – you need to scout! If nothing else, this will confirm that your control measures are working. Begin scouting as soon as you enter the garden and especially before you foliar spray or do soil drenches. Here’s a solid article that takes a little bit deeper dive into the topic.
Happy Harvests!
— The Lit Farmer —
