Differentiating billbugs:
Distinguishing billbugs from the grubs is very difficult because they are look-alike of white grubs. The only difference you can see in the larvae of these two is that the grubs' larvae have legs and billbugs' larvae do not have legs. Similar to grubs, they also shrink their body when touched or feel any activity around them.
They love to stay hidden under the soil about 1-2 inches deep, but you can identify their presence under the soil where thinning or yellowing of grass has developed. If you touch that spot with your hand it would be very soft and delicate to pull out.
Adult billbugs have a hard and darkish-brown textured shell masking their complete body. They also look weird and wild. They can release a smelly chemical when smashed. This liquid may cause skin irritation or allergy for humans and pets at home.
Why and how to control billbugs?
A simple answer to why to control billbugs is that they destroy the entire effort you have put in to make a beautiful lawn. Hence, they live under the soil and near the roots, so they keep on feeding on the roots of the grass and make the soil brittle. When the larvae grow up and become adults they also approach other plants in the lawn and eat them.
Now coming towards how to control billbugs, it would be fair to say that you must inspect the spots where they are present in larger amounts, and then decide to perform killing. The larvae can be easily caught by pulling the bare and weak patches with the hands by putting gloves on. To control the billbugs, it is important to take action in the late spring or early summer before they get multiplied quickly and become uncontrollable. Keep in mind that if you will not take the right action on time, then you will have to lay a new lawn from scratch.