Leaf-Footed Bugs: Your Garden's Achilles Heel

Leaf-footed bugs generally live up to their name: most species have flat, leaf-like structures on their hind legs.

But like every family (in this case, Coreidae, a word that has nothing to do with legs or leaves) there are a few relatives who fail to toe the genetic line. 

Some, such as the apparently underachieving squash bug (so-called for their preferred diet, not how they often die), don’t have very prominent leaf-like extensions at all. As a result, certain entomologists argue that it might be more scientifically precise to call theme "plate-legged bug" or "broad-legged bug" rather than leaf-footed. 

However, like many other misleading names — think guinea pig, bald eagle, and jumbo shrimp — “leaf-footed” has stuck.  

Mouthing off 

Cold-blooded and native to the rainforest, leaf-footed bugs are known to seek out similar warm, humid climates. They’re found on every continent except Antarctica.  In areas where the weather is consistently toasty, leaf-footed bugs can remain active throughout the years. Elsewhere, they go dormant.

Wherever they are, they can be tricky to spot.

If you think that the bug’s distinctive faux feet will give them away, think again. This is no large, menacing-looking Joro spider we’re talking about.

Instead, the leaf-footed bug’s brownish-grey color serves as a sort of drab camouflage, helping them blend in with their surroundings (they also have a propensity to hide on the underside of leaves). It’s only the damage left in their wake that tells you they’ve been there, turning your backyard into a buffet. 

These little pests (typically measuring an inch at the most) use their sucking mouthparts to extract the sap from your flowers and ornamentals, making a healthy garden look as sad as a days-old, wilted spinach salad. Fruits and vegetables often take the brunt of the leaf-footed bugs’ destructive behavior; not content to simply damage the leaves and stems, they pierce the developing fruit with their mouthparts. This causes dimpling, blemishes, and scarring and just generally makes the fruit less appealing to consume.

On second thought, maybe bad-mouthed bug would be the best name of all. 

Rules of detachment

One of the great mysteries of leaf-footed bugs is this: what exactly is the purpose of those leaf-shaped leg expansions? 

No one seems to know for sure.

One theory is that in some species the male uses them as part of their elaborate mating ritual or to combat rivals, giving a whole new meaning to the idea of putting one’s best foot forward. Another thought is that the unique shape might help with grasping onto plants or aid in sensory functions.

We do know with certainty what they are not used for, however. They play no part in autotomy, the leaf-footed bug’s ability to deliberately detach its legs as a way to escape predators. If you’ve ever seen a gecko or anole shoot off its tail while trying to fend off, say, your pet cat or dog, that’s autotomy in action. 

If a predator grabs a leaf-footed bug by its leg, the limb comes off a pre-determined weak point. However, the weak spot is typically on the leg itself, not on the leaf-like expansion, meaning the expansion doesn’t aid in the detachment process. Research suggests that in the case of leaf-footed bugs, autotomy for escaping predators might be an "exaptation." This means the trait originally evolved to help them escape from sticky situations — getting stuck in the secretions of a carnivorous or other rainforest plant — or to reduce injury from non-predatory encounters but was later found to be useful in a new context.

The good news for leaf-footed bugs is that even if they’re down a leg or two, they can still move around, albeit more slowly and with greater expenditure of energy — which is far better than getting eaten by a predator or being digested by a sundew. But the trade-off is this: Unlike the gecko’s regenerative tail, the leaf-footed bug’s severed leg doesn’t regrow. No matter how many feet you have, they’re no good without a leg to stand on.

Swept off their feet

Given the extent of their gnawing, leaf-footed bugs can be a garden nuisance. Here are some non-chemical ways to banish them from your garden:

• Inspect your plants for leaf-footed bugs and their eggs. If you see a small number of adults or egg clusters, you can handpick and remove them. Drop them into a container of soapy water to kill them.
• Use insecticidal soap spray to control a more widespread infestation of adults and nymphs.
• Apply neem oil spray to disrupt the growth and development of adults and nymphs. 
• Encourage natural predators such as ladybugs, minute pirate bugs, and assassin bugs by planting flowers to attract these beneficial insects.
• Keep your garden clean and free of weeds and debris that leaf-footed bugs might use for shelter or egg-laying. 
• Consider row covers to protect young seedlings.  

These sure-footed approaches should help you literally sweep leaf-footed bugs off their feet.