There’s a secret to finding flea beetles. I didn’t exactly “discover” it — you might say I’ve learned it by experience over the years.
Growers are always speculating about flea beetle, and whether or not the pest will show up in their field. The only way to know — and here’s that secret I’m talking about — is to scout for them.
Often, growers wait to hear from neighbours as to whether or not there’s a flea beetle problem in their area. Fact is, you can have hot spots pop up where flea beetle is an issue, and other spots right next door can be flea beetle-free. Don’t wait for a neighbour to find something. It pays to take the time to scout for yourself. Have a look at your fields with your own eyes and start scouting as your canola is emerging, checking for not only shot holes on the plant leaves, but also for feeding on the stem which can be very damaging to young seedlings.
There are three types of flea beetles but the two most common are striped and crucifer; depending on the year there may be one or both present in your field.
Since there is only one generation of flea beetles produced each year, you can observe flea beetle densities in the fall, the Canola Council of Canada notes. New adult flea beetles begin emerging in late July and early August. After mating and egg laying in early June, the overwintered adults begin to die off. The young larvae feed on the roots of the developing canola for three to four weeks. They are present from about mid-June to late July.
These adults feed on the green tissue of suitable host plants that are still present. Feeding may continue into mid-October. By mid-September, most adults have usually entered a dormant, overwintering stage. This is the first sign of potential problems next spring. Only one generation of flea beetles is produced each year.
Bottom line: there’s no better way to pick out a potential problem than to check for yourself. Word of mouth can be a great tool to use, but never rely on it as your primary method of information gathering!