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Bug of the Week is written by "The Bug Guy," Michael J. Raupp, Professor of Entomology at the University of Maryland.

Deception and defense on cup-plant: Keel-shaped treehopper, Entylia carinata


Bizarre treehoppers often resemble plant parts more than insects.


It’s always an adventure to try a new herbaceous perennial in the flower bed. This year’s guinea pig was Silphium perfoliatum, cup-plant. What started out as a few broad leaves in spring turned into a five-stemmed leviathan almost eight feet tall with scores of bright yellow blossoms. This plant is a magnet for pollinators of all description including butterflies, bees, wasps, and beetles.



Want pollinators? Plant cup-plant.

In addition to providing nectar and pollen, its vascular system provides a storehouse of nutrients for myriad sucking insects. Beneath several large lanceolate leaves, colonies of treehoppers set up shop sucking sap from vascular bundles running through the leaf. We met beautiful tropical treehoppers in a previous episode of Bug of the Week. Treehoppers are also known as thorn bugs by virtue of the fact that many species bear a strong resemblance to thorns of plants. These bizarre appendages are formed by genetically programmed growth of the exoskeleton on the pronotum, or upper surface of the first thoracic segment of the insect. By mimicking plant parts like thorns, treehoppers may escape recognition by the searching eyes of vertebrate predators such as birds and other reptiles.

A fierce ant stands guard over a strange treehopper nymph.

With its strange keel-shaped pronotum, Entylia carinata looks more like leaf damage or a piece of plant debris than it does a tasty bug. While deception is one part of the game to avoid being eaten, treehoppers have an additional plan for defense. Like froghoppers, scales, sharpshooters, and aphids we met in previous episodes, treehoppers excrete large quantities of carbohydrate-rich honeydew. Honeydew is manna for ants and every colony of Entylia carinata on my cupflower was attended by one or more alert chestnut colored carpenter ant poised for attack. When I gently poked the treehopper, ants swarmed my finger to deliver bites with powerful jaws. Made me not want to mess around with the treehoppers! In addition to cup-plant, other members of the Asteraceae, including fleabane, crownbeard, and sunflowers, serve as hosts for these remarkable masters of deception.



Colonies of treehoppers are tended by feisty ants. Watch as the ant’s antennal stroking is rewarded with an uplifted abdomen and a droplet of honeydew.


The interesting article “Treehopper Diversity (Hemiptera: Membracidae) of Little Orleans, Allegany Co., Maryland” by Charles R. Bartlett,  Lewis L. Deitz, Mark J. Rothschild, and Matthew S. Wallace was consulted in preparation of this episode.