Are Insects the Cause of Your Lawn’s Brown Spots?

Has your Kansas City area home’s lawn began forming brown or discolored spots? A reason this is occurring may be due to insects. When it comes to insect infested lawns, it is important to understand that their identification and control is extremely difficult unless you know what to look for and where. There are two distinct types of these lawn damaging insects, which helps finding a solution to this lawn care problem. Heritage Lawns & Irrigation put together our best guide to classifying these insects.


Root feeding insects typically feed on the roots, often causing wilting and other drought-like damage.

Bluegrass Billbug – Rarer than grubs, Billbug damage often appears during the summer months through mid-August. Billbugs are small, 1/4 inch, blackish beetles, often found on hard surfaces in spring. Eggs are deposited on grass stems in spring and as larvae emerge, they feed on the stems then migrate to root systems causing irregular yellowing and browning areas in lawns. Control is recommended in May when adults are visible on hard surfaces.

White Grubs – The larvae of the common Junebug can cause considerable damage to lawns. Grub damage, when severe, can loosen the sod so it can easily be lifted up. Browning areas and sponginess can indicate grub damage. By lifting up the loosened sod, grubs are easily seen as “c” shaped whitish larvae. Control is best in the spring and summer when damage is evident.


Blade feeders typically cause damage by withdrawing the plant’s sap.

Sod Webworm – Adult webworms are the typical lawn moths that fly erratically near the grass. The larvae of these moths cause the damage. Damage occurs at night as the webworm larvae feed on the leaves and crowns of the grass. Sod webworms are just under an inch when fully grown and are light brown in color with darker spots. Chewed off leaves and sheaths and green pellets (excrement) in the thatch are signs of sod webworms. Thorough watering of damaged areas will cause worms to surface and are easily seen.

Aphids – Aphids, often called greenbugs, can quickly damage lawns in mid to late summer. Damage is typically seen as an orange-yellow area often found under trees. Aphids are very small, greenish insects that can be easily identified by simply sweeping your hand near the edge of the affected area. Control when damage is visible.


Ants – Ants do not damage lawns. They move into thin lawn areas but do not cause the thinning, so control is not recommended.

Nightcrawlers – Nightcrawlers are very beneficial to lawns. Lumpy soil can occur when nightcrawlers are in large numbers. When this occurs, vertical moving and/or dethatching can reduce lumps and help control the population. Other forms of control are not recommended.