Adult and larval pictures of Crane Flies.
Recently (this past year) we have seen castings in the spring on driveways in East Aurora / Elma, Glenwood, Springville, and Arcade. These worm castings are usually from Crane Flies.
Crane flies resemble very large mosquitoes. Adults are harmless but the larvae of the "European" Crane Fly can damage the roots of your lawn, and even kill patches of lawn. New lawns are especially susceptible because their root system is not well-developed. Crane fly larvae feed in the root zone during winter months.
This is why it is best to control crane fly larvae in the fall before significant root damage is done. Crane Fly larvae and Cutworm larvae are very similar in shape, color, and size. Both of these larvae do damage to your lawn. I would suggest a visit, to determine your threshold. The commonly-cited injury threshold is 15 larvae per square foot; however, this will vary depending on overall turf health.