Pest infestation


Hi there,

I contacted Agriculture Canada, and they referred me to master gardens of ontario. I have bug infestation in my yard.

How to kill leatherjacket (crane fly Larvae) in my garden? They killed all my tomatoes, cucumbers, lettuce and strawberries? Basically they wiped out all my plants in the garden. I need a method to kill all immediately, and also the next generation




We are so sorry to hear that your garden has been devasted by a pest infestation.

The European crane fly larvae (aka leatherjacket) is primarily a turf pest. They complete one generation cycle per year in Ontario. The larval stage that causes the most damage is the fourth moult or instar (the form in your photo), when they feed in spring, during the day at or below the surface of the soil, dining on root and crown of grass. When nights are damp and warm, they come up to the surface and munch on grass stems and leaf blades. By mid-June, they stop eating and move down slightly deeper into the soil to pupate. Adults emerge in September, mate, and lay eggs on the surface of or 1 cm down in the soil. The eggs hatch, and the larvae feed and moult throughout the fall, and usually overwinters in the turf as third or fourth instar. Then they wake up in spring and start eating again.

Leatherjackets depend on moisture to survive, so they spend most of their time inside turf. They are not easy to detect. Out in the open, they don’t live long before they dry out and die, or are picked off by birds.

Due to pesticide regulation in Ontario, as a homeowner your remedy is limited to applying nematodes to the soil in the spring and/or fall as a means of biological control of the eggs and larvae. Eradication of pests, of any kind, is not really possible; it is more realistic to aim for an acceptable level of control.

Please take a look at this fact sheet on European crane fly larvae by the Ontario Ministry of Agriculture, Food and Rural Affairs. At the end of the document, you will find the names of the kinds of nematodes you need. Nurseries should carry them, but only at certain periods of the year timed to application. Timing and moisture are critical to success, so follow the instructions on the package closely. Here is a previous Toronto Master Gardener answer on nematode application for your reference.

We wish you the best of luck controlling the pest and getting your garden back!