Question about grubs in the ground under my grass
Dear Maryland Extension, While digging a small hole in my lawn today, I found many grubs in the ground. They are of two types: half-inch-long white worm-like ones (shown in photo IMG_4745 attached), and inch-long brown insect-like ones (shown in photo IMG_4746 attached). I found them wherever I dug in the lawn. They are located 3-4 inches underground. I also found some holes dug into the ground -- I think by crows or rodents looking to find and eat the grubs. Are these grubs a problem, and if so, how do I prevent them in the future or kill them now? Also, a broader question: How do I know if I have too many insects in our lawn? Sometimes I'm walking around outside in the summer, and I'm disturbing small moth-like flying insects with every step.
Montgomery County Maryland
There are many types of grubs that may be in your soil such as Japanese beetles, masked chafers, June beetles, etc. The photo on the right shows a cicada nymph and are not a concern. You can leave them for bird food.
It is normal and not problematic to have a few grubs in the soil (in fact, helpful because it keeps the grub predators around.) Unless you are seeing around 10 per square foot, and your lawn suffered severe damage in late summer to early fall it does not warrant the expense and impact of spreading any pesticides. Here is more on grubs https://extension.umd.edu/hgic/topics/grubs-lawns
The insects that you may be noticing with wings are most likely resting and not a problem. You can send us photos if you are noticing symptoms so we can see what you may be dealing with.