Now that most Minnesotans can see the lawns again after a record-breaking winter, some aren’t too happy with what the melt has revealed. In the metro especially, people are noticing big, juicy white grubs feeding on their lawns.
Who are these grubs?
White grubs are the immature form of a large group of beetles, scarab beetles. Common scarab beetles in Minnesota include june beetles, rose chafer and, of course, Japanese beetles. Depending on where you are in the state, these are likely Japanese beetles, but it is still important to identify the insect you are looking at.
While scarab beetles are related, how long they spend in the soil as grubs and how much damage they do varies a lot by species.
If you are thinking about putting major time or money into dealing with white grubs, it is worth taking a second to confirm which species you are dealing with. This tool from Cornell University can be used to compare the size, lifecycle, and pattern of hairs between different grubs.
Why do white grubs matter?
Different species have different potential to do damage. The main grub that does significant damage in the metro and southeastern Minnesota is the Japanese beetle.
Japanese beetle grubs feed on the roots of grasses from June through the fall, they then ride out the winter a few inches under the soil. As soil temperatures warm, they return to the top few inches of soil, feed on roots, then pupate.
In mid-June adult beetles will emerge and feed on many species of plants. These adults lay eggs, and the cycle starts all over again.
Source: umn.edu
Photo Credit: GettyImages-CreativeNature_n
Categories: Minnesota, Crops