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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.

Rain on a sunny day: Lanternflies, Fulgoridae


Click here to see the lantern reveal the flash coloration of its hindwings.


With the Northeast still embraced in winter’s big chill, Bug of the Week returns to the tropical rainforest where last week we visited the Mexican redrumped tarantula. This week we visit a curious clan of insects known as lanternflies. While standing in the shade of a large tree, I was surprised by small raindrops falling from a cloudless tropical sky. Feeling a little like John Fogerty, I wondered where the rain was coming from on a sunny day. A very observant student discovered several wonderful lanternflies hiding on the lichen-covered bark of the tree’s trunk and branches. The insect’s dusty brown and white color blended marvelously with the bark of the lichen covered tree.

The grotesque adornment on the head of the alligator lanternfly might give small birds nightmares.

These strange insects merrily suck plant sap and expel liquid leftovers from their derrieres. Lanternflies are relatives of aphidscicadas, and sharpshooters we’ve met in previous episodes of Bug of the Week. They obtain nutrients by inserting soda straw-like mouthparts into the vascular system of the tree and removing sap. Relatively large volumes of sap must be processed for the lanternfly to gain sufficient nutrients and the excess liquid squirts from the rear end of the insect as liquid called honeydew, hence the “rain” on a sunny day. Many other insects, including ants and butterflies, consume lanternfly honeydew as a rich source of carbohydrates.

Camouflage is one of the important ways a lanternfly evades its predators in the forest. A second line of defense was revealed as I attempted to capture a lanternfly. As my hand approached the insect, the bug jumped from the tree and opened its forewings to reveal a bright scarlet pair of hindwings. The insect took flight in a flash of color, settled on the bark of a nearby tree, and quickly disappeared from view on the lichen encrusted background. This type of flash coloration is a defense commonly used by other insects such as grasshoppers and moths.

Some species of lanternflies use one more trick to fool predators, and that is to look like a predator themselves. Lanternflies in the genus Fulgora have an enlarged hollow structure adorning the front of their head. This structure has distinct patterns of color creating the image of two eyes and a grinning row of teeth. It is no surprise that common names for this insect are the alligator bug and dragon-head bug. Image the surprise of a bird or lizard about to make a meal of a juicy bug when suddenly the predator is staring into the crazy face of a leering reptile! If I were a small lizard or bird, this ruse surely would be enough to make me lose my appetite.

Mottled outer wings allow the lanternfly to blend in beautifully with the bark of the tree. 


The excellent references “The Insects: An Outline of Entomology” by P.J. Gullan and P.S. Cranston, and “Amazon Insects” by James L. Castner were used in preparing this Bug of the Week. Piotr Naskrecki’s wonderful blog was also used as a reference for this episode. Special thanks to the hearty crew of BSCI 339M: ‘Tropical Biology in Belize’ for providing the inspiration for this Bug of the Week.