Overview
Katydids are a large group of insects in the order Orthoptera, related to grasshoppers and crickets. Some katydids have been called long-horned grasshoppers because of their long and slender shape, but actually katydids are more closely related to crickets than grasshoppers. There are over 8,000 species worldwide, with the greatest diversity in the tropics, and 255 species are native to North America.
Katydids are classified in the family Tettigoniidae, which includes about twenty subfamilies. The main groups of commonly encountered katydids include the true katydids (Pseudophyllinae), false katydids (Phaneropterinae), shield-backed katydids (Tettigoniinae), meadow katydids (Conocephalinae) and coneheaded katydids (Copiphorinae). There are about 20 species native to the Midwest.
Katydids are usually green and camouflaged to blend in with foliage, more commonly heard than seen. They have a body taller than it is wide and thin hind legs that are longer than the other pairs of legs. Some characteristics that distinguish katydids from other orthopterans include having the wings held vertically over body (like a roof of a house), hearing organs on the front tibia, all tarsi with 4 segments (crickets have 3), a typically flattened and sword-like ovipositor, and very long, thin antennae as long as or longer than the body (in grasshoppers the antennae are always relatively short and thickened).
The antennae are covered with sensory receptors that help katydids navigate in the dark, since they are primarily nocturnal. Depending on the species, they can be from ½ to 4 inches long. Females tend to be larger than males and have a noticeable ovipositor at the end of the abdomen for laying eggs in plant stems or into the ground.
Many species are leaf-shaped to blend in with their environment to prevent predation. During the day they rest in a specific diurnal roosting posture to make them look even more like just a leaf on the plant. Wing form varies widely, with most having long wings that cover the body, but some species have short wings or are nearly wingless. They tend to be poor flyers, and some only flutter their wings during leaps.
Every so often a pink katydid shows up. It’s been estimated that pink coloration occurs in one of about 500 individuals, a condition called erythrism. It is caused by recessive genes, similar to the situation for albino animals. The New Orleans Audubon Insectarium acquired a pink male and a pink female katydid to produce a brood of pink katydids which are now on display there. These individuals prominently stand out in their normal green environment and therefore would not be likely to survive as predators could find them too easily. But in the protected insectarium they grow and live just like regular green katydids.
Katydid Life Cycle
In Wisconsin, katydids overwinter as eggs. Females deposit eggs in soil, plant stems, or tree bark in late summer or fall. The adults die off, and the following spring the eggs hatch into nymphs. These generally resemble the adults except they are smaller and lack fully developed wings and reproductive organs. As the insects go through incomplete metamorphosis, the wings gradually appear through generally five successive molts. Depending on the species, the female’s ovipositor may be short and curved like a sickle or long and saber-like. Those species with sickle-shaped ovipositors typically lay eggs in plant stems, while those with elongate ovipositors generally lay eggs in grass stems.
Like other Orthoptera, katydids have chewing mouthparts, and most are herbivores but rarely cause significant plant damage to crops or ornamental plants. You may find some feeding on leaves and flowers in your garden or on your potted plants, especially in late summer. Some, especially in the tropics, are predaceous, feeding on other insects or eggs. Most are nocturnal, but some are active during the day. They tend to be found in grasslands, open woods and along edges of plantings in suburban or rural areas, with many species in the treetops. They an important food for many animals, including birds, bats, rodents, tree frogs, spiders, and praying mantids.
Katydid Song
The rasping sounds created by the common true katydid (Pterophylla camellifolia), native to much of the eastern US and into southern Wisconsin, is said to resemble the sound of the words “Katy Did! Katy Didn’t! Katy Did! Katy Didn’t!”, hence the common name for these insects – but not all katydids make this classic sound. Each species has its own songs, with reproductive, territorial, aggressive, or defensive purposes.
Males are mainly responsible for these songs, but in some groups the sexes form duets. Sounds produced by other species include continuous songs known as trills and a variety of clicks and buzzes created by stridulation (friction), all produced by special structures on the front wings. There is a rigid “scraper” on one forewing that they rub against a comb-like “file” on the other. The size of the insect, the spacing of the ridges and the width of the scraper determine what sound is made. Some kinds of katydids have an ultrasonic call, while a few produce vibrations by thumping on twigs that are detected by other katydids. In order to detect these sounds, katydids have a tympanum, a slit-like or flat patch on each front leg, which functions as an “ear” to detect these sounds (plural = tympana). They raise a leg to help pick up the sound.
Calls can be heard both day and night, but in Wisconsin katydids generally start late at night and continue into the early morning hours in late summer, with quick bursts of two, three or four notes. Males nearby often alternate their songs in a back and forth melody. As temperatures decrease in the fall, the songs grow slower and usually end by October.
Males call to attract females. There is a lot of competition between males, and females try to select healthier males, judging their fitness by the sound of their trill (louder and more fluent is better). When the insects mate, the male passes a sperm packet (spermatophore) to the female. The males increase their chance of reproductive success by providing additional protein (a spermatophylax, which may require as much as 40% of his body weight to produce) attached to the spermatophore for the female to eat to help her develop her eggs. In species that produce large food gifts, the female is the one that seeks a mate. Males that produce large food gifts mate one or two times in their lifetime, while males that produce smaller gifts can mate more times, but are less likely to be selected by females.
Author: Susan Mahr, University of Wisconsin—Madison
Reviewers: Allen R. Pyle, Horticulture Outreach Specialist, Bruce Spangenberg, Horticulture Outreach Specialist, UW—Madison Extension
Revised: October 2026
