Monday, July 28, 2014

Hairy-legged Fly, a Gardener's Friend

Female Trichopoda pennipes. © Beatriz Moisset
Unsung insect heroes of the native plant garden abound. Pest fighters such as lady beetles, praying mantises and lacewings are receiving growing attention. But pest fighting doesn't end with the three above mentioned. Wasps and flies of many sorts provide invaluable pest control services. Let us look at one of them, the hairy-legged fly (Trichopoda pennipes).

Male Trichopoda pennipes. © Beatriz Moisset
The abdomen of the colorful hairy-legged fly is bright red or orange on the male and with a black tip on the female. Both wear funny looking bell-bottoms on their third pair of legs. This flare is made of a tuft of hairs that gives these flies their name. Like all other flies, they have only one pair of wings. The back wings have been reduced to small balancers, called halteres, hard to see in most species. This fly is the exception. The halteres are relatively prominent and bright orange. If you have been struggling to identify flies by the number of wings and the presence of halteres, you want to start with this example.

They are often seen visiting flowers and drinking nectar. Thus they may perform some pollination. But their most important role in the garden is what they do to feed their young. They hunt a variety of insects on which they lay a single egg. When the baby or larva emerges from the egg, it drills into the hapless bug and proceeds to eat its insides.

Green stinkbug, Chinavia hilaris. © Beatriz Moisset
Two insidious pests are among its favorite hosts: the green stink bug and the squash bug. The green stink bug attacks a number of crops, including corn, cotton and soy bean. The squash bug feeds on squash and related vine crops.

Squash bugs, Anasa tristis on pumpkin. © Beatriz Moisset
The hairy-legged fly deserves more recognition than it gets. If you want to encourage it to visit your garden, reduce or eliminate pesticides and provide native flowering plants that bloom through the seasons so the adults find nourishment. If you are helping pollinators you are probably doing all this already.

Male Trichopoda pennipes. © Beatriz Moisset

Just the fly for your pumpkin patch

For more on pollinators and other flower visitors read the e-book:
Beginners Guide to Pollinators and Other Flower Visitors

© Beatriz Moisset. 2014


  1. A new species for me to keep an eye out for. Thank you!


  2. Well, cool! I have seen one in our yard, so hopefully there are more, and they will stick around. I am tickled to see a pretty good assortment of insects and spiders. I am going to put a link to this post in the FB group, Gardening with Nature in Mind.