Beware of anyone who tells you to spray an insecticide with the exact same threshold (number of insects per plant) year after year. When crop prices go up, yield potential is greater, and the insecticide cost is lower, that means the ECONOMIC threshold for spraying has gone down. Keep in mind, the reverse is also true. If crop prices and yield potential go down while at the same time insecticide costs go up, that means it would take more insects per plant to justify spraying.

Here are 5 important factors when it comes to making the decision whether or not to spray an insecticide on your farm this year.

Finding harmful insects in your field.

This is by far the most important factor. We do not recommend foliar insecticide applications without seeing yield-robbing bugs in fields.

Cost of insecticide.

This is certainly second on the list, because ultimately I care what I spend, and I’m sure you do, too. Fortunately, many insecticides at the full rate cost under $2 per acre. However, if you are after spider mites or if you have pyrethroid-resistant insects, you could easily spend $6 per acre or more.

Total value of the crop.

Not only should you be more interested in protecting a $900/acre crop instead of a $90/acre crop, but the value of stopping insects is almost always greater in the high-dollar crop, as well. For example, if an insecticide application can help your yield by 2%, that’s $18 per acre in the $900 crop vs. only $1.80 in the $90 crop. Now imagine how much a 10% or 20% gain can be when you’ve got a bad insect year!

Other applications being made.

The point of this is cost and ease of application. When you are already out spraying something else (fungicide, herbicide, fertilizer, Natural, etc.), adding an insecticide costs no more in terms of the application or time. That’s why the most important time to scout for insects if you want an amazing return on investment is always right before you spray anything else.

Are you a regular user of insecticide?

This may seem like a strange thing to include in my list, and while all the other things in points 1 through 4 are more important, here’s why this enters in: potential insect pressure. If you use some insecticide on your farm each year, you are often able to keep insect numbers in check. However, if uncontrolled, insects will often lay eggs or overwinter on your farm, meaning you could have an explosion of harmful pests the following year. Regardless of whether or not you regularly use insecticide, we will always encourage you to scout your fields; but if you don’t typically spray a bug-killer, we would advise you to be very diligent in your scouting routine. Year after year, the worst yield losses we see from insects are predominantly on farms where insecticide is rarely used.