Depending on your local restrictions or bylaws you may consider a broad spectrum insecticide. Good lawn care practice will usually limit the infestations of insects. Investigate aerating annually, reseeding annually, fertilizing on a regular basis, mowing at correct height and proper watering regime. These things will make your lawn healthy and hopefully resilient to attack.
Seem to like lawns that are soggy, so improving drainage may be called for anyway. Do not treat unless larvae 25 per square foot or more. Have heard horror stories of dying robins flopping around all over the place after lawns treated for European cranefly.
