Leaf-Footed Bugs

Their tiny leaf-shaped feet may looking charming, but these cousins to stinkbugs can cause almonds, tomatoes, pistachios and pomegranate fruit to be aborted.

Leaf-footed bug nymph (Judy Gallagher) CC BY 2.0

Leaf-footed bug description

Leaf-footed (or leaffooted) bugs are medium-sized insects with long, sucking mouthparts. Adults are normally 3/4” to 1” long, with a narrow brown body. Leaf-footed bugs (Leptoglossus) are easy to identify because of the leaf-shaped bits sticking out of their hind legs. There are three species of leaf-footed bugs native to the western United States:

• L. zonatus 
• L. clypealis
• L. occidentalis (western conifer seed bug)

The three species look very similar, except that zonatus has two yellow spots behind the head and clypealis has a thorn-shaped plate on the front of its head called a clypeus. All species of leaf-footed bugs have white zig-zags on their wings.

Western leaf-footed bug (Andy Reago & Chrissy McClarren) CC BY 2.0

Leaf-footed bug lifecycle

Leaf-footed bugs overwinter in wood piles, citrus or juniper trees, or buildings. They can also be found under tree bark. In spring, adults fly in search of winter weed seeds, young fruit, and a place to lay eggs. Leaf-footed bugs that have survived the winter can carry 200 eggs. These brown, cylindrical eggs are laid in a line, end-to-end, usually on a stem or leaf midrib. Nymphs emerge from the eggs and can be identified by the dark head and legs, and orange to reddish-brown body color. Leaf-footed bug nymphs are often confused with nymphs of the beneficial assassin bug (Zelus renardii), which have lighter colored legs and antenna. Also, assassin bug eggs are barrel-shaped and laid together in groups that are protected with a white cone covering.  

Leaf-footed bug damage

Leaf-footed bugs generally do not do a lot of damage. This changes when populations are especially high, due to mild winters. Adult L. zonatus feed on tomatoes, pomegranates, almonds, pistachios, and watermelon. L. clypealis prefers palm trees and yucca, while L. occidentalis feeds primarily on conifer trees. All three species feed on many ornamental trees and shrubs. Leaf-footed bugs have mouthparts that pierce fruit, shoots, and leaves, to suck out plant juices. Leaf-footed adults are able to probe deeply enough to reach fruit seeds. When a seed is found, digestive enzymes that liquify the seed are excreted. Damage to the seed often causes the parent plant to abort that particular nut or piece of fruit. Leaf-footed bug mouthparts are also known to carry a fungal yeast (Eremothecium coryli). As the bugs feed, this yeast is introduced into the fruit or nut, causing depressions or discoloration, but no other damage. Of course, like most bugs, they do poop on your fruit.

Generally, control measures are not needed. If leaf-footed bugs have become a problem, these sanitation measures will help:

• Keep wood piles away from buildings and eucalyptus and conifer trees.
• Dispose of culled fruit.
• Eliminate seed-bearing weeds.
• Use row covers.
• Inspect plants daily and handpick. Bugs can be crushed (they stink!) or dropped in a can of soapy water.
• Encourage predators, such as birds, spiders, tachinid wasps, and assassin bugs by providing water and natural habitat.
• Avoid using broad-spectrum pesticides that can kill predator insects.