Insect pests play a big role in the overall health of our lawns. If we want to gaze into the future to see what kind of insect activity we will be seeing this coming summer, we should actually look backwards to see what happened last year. Past is prologue, after all.
I spent some time at our Boston North branch this past week and while driving around I could not help but notice that last summer’s drought took a heavy toll. One lawn after another was dead, not enjoying winter dormancy but dead as a door nail. Turfgrass plants are very tough but the prolonged lack of rain coupled with soaring summer temperatures were just too much for them.
Hot, Dry Conditions are Perfect for Chinch Bugs
But environmental factors weren’t the only thing in play last year. Insects respond to the weather too. Hot, dry conditions are just perfect for chinch bugs. These little critters are about the size of a pencil lead when fully grown with a distinctive hourglass-shaped design on its back. Chinch bugs inhabit the surface and thatch layer of our lawns and cause damage by sucking the sap from turfgrass plants.
A normal lawn will have a background population of chinch bugs that do not cause enough damage to be noticeable. However when the weather is hot and dry their populations explode. We saw a much higher than average amount of damage attributable to chinch bugs last year and because of that we expect there to be a correspondingly high population that survives the winter. We are prepared for them as they return, if you know what I mean. Be on the lookout for Chinch Bugs.
How to Identify Bluegrass Billbugs
The Bluegrass Billbug is probably the most misdiagnosed lawn problem today. This tiny weevil resembles a white grub except that it is smaller in size, has no forelegs, lacks the distinctive “C” shaped body and inhabits a different region of the lawn; that is to say that they are exactly alike except they are totally different.
The reason that billbugs are so difficult to diagnose is that their damage resembles heat & drought stress at first blush. Sometimes you can detect a damage pattern, saying to yourself “I know that they’re there, I just have to find them to be certain”. And there’s the grub – good luck finding them.
Billbug eggs are laid in the sheaths of the turfgrass plant, the tubular portion of the leaves where they attach to the stems. Since the sheath is hollow, it provides shelter and concealment to the newly hatched grub, which then begins to descend the sheath towards the crown, the central growing point of the turfgrass plant, feeding as it goes. Once the grub consumes the crown, the plant is dead.
The grubs will continue to hide in the thatch, feeding until they reach pupation. The brown to black adults emerge as small weevils with a distinctive snout, or bill, thus the name billbug. On warm April days, billbugs can be found walking across driveways, traveling from their overwintering homes in the duff that surrounds lawns. It’s logical to assume that the cold-blooded billbug is drawn to black surfaces like driveways due to their relative warmth early in the season. This behavior of being drawn to warm surfaces is reflected in the damage patterns that you will encounter later in the season. Billbug damage tends to be closer to driveways and walkways than further into the lawn.
How to Control Chinch Bugs & Bluegrass Billbugs
For both Chinch Bug and Bluegrass Billbug, a surface insect control treatment during the early spring when overwintering adults emerge from hibernation is a good strategy to prevent significant damage later on in the summer.
Learn about the Insect Control Treatment that is included in our Signature Lawn Care Program.
- Bob Mann, Agronomist