Questions? Enter keywords in search box below:

Crane fly damage

Crane fly larvae feed on grass roots but a few larvae will not cause noticeable injury to healthy grass. However, high numbers cause so much root injury that the grass can no longer get the water and nutrients it needs and the turf dies as the weather gets warm and dry, usually in summer. You'll see large, irregular patches of dead grass when this occurs.

The commonly-cited injury threshold is 25 larvae per square foot; however, this will vary depending on overall turf health. To determine larval density dig a square foot (12"x12") area of turf and look for larvae in the root zone just below the soil surface.

Most turf damage occurs between late fall and the following spring. Adults emerge during summer and lay eggs that hatch into root-feeding larvae. Young larvae that occur during the fall are also the easiest to control.

Crane fly control

Since healthy lawns can sustain considerable crane fly damage there are only two situations where routine insecticide applications may be needed. First, new lawns that lack a robust root system can be severely damaged if infested with crane flies so fall applications of insecticides may be needed during the first fall after planting. Secondly, commercial turf areas (golf courses, athletic fields, and so forth) where scouting has revealed a larval density greater than 25 per square foot. Lawn insecticides that are labeled for white grub control are often approved for crane fly control as well. However, read product labels carefully to ensure that crane fly is listed (see White Grub Control in Lawns).

Caution: treating lawns with insecticide can be risky. You should take precautions to avoid contaminating nearby water but also apply enough overhead irrigation to wash insecticides into the root zone, Also, crane fly larvae that have ingested insecticide can be poisonous to birds that feed on these larvae. Many bird kills have resulted from excessive insecticide applications targeted at crane flies.

'Bugs Needs Your Support!

If our information is useful help us maintain and grow 'Bugs. Visit our Support Page or shop at Amazon, one of our favorite affiliates. Amazon is not just books and Kindles, they even have bug stuff!