Summary: Katydids are not generally thought of as true pests, although they do feed on plant leaves and fruit, making them a nuisance for some growers. However, many gardeners enjoy their song and choose to let them be. If a large katydid population is threatening your garden or crop, there are several options for katydid control.
While not always necessary, gardeners and fruit growers who are experiencing a large nymph population may find insecticides such as Spinosad to be helpful. This particular insecticide is low in toxicity to humans, other mammals and birds, which makes it relatively safe, even for edible plants.
In most areas, katydids are more of a nuisance than a true pest, but for those growers who are experiencing a higher than normal nymph population, cultivation or chemical insecticides such as Talstar Pro may be the answer.
Katydid may not be a household term, but most readers have probably seen and heard these large winged insects many times before. Many people falsely identify these shrilling insects as grasshoppers, because they do indeed belong to the long-horned grasshopper family, known as Tettigoniidae.
Like many grasshoppers, Katydids are typically green in color, although a pink variety is sighted from time to time. Ranging from a little over one inch to five inches in length, Katydids are also similar in size to the modern grasshopper.
However, while they may resemble their grasshopper "cousins", the katydid's namesake actually more closely resembles that of a cricket.
On a late summer evening, these nocturnal insects can be heard taking part in a bizarre mating ritual, in which the male of the species "sings" to attract the female, creating a shrill call by rubbing his forewings together. The females response to this mating call is to chirp a song of her own, which many say sounds like "katy did, katy didn't."
These musical insects can be found in the Easter United States and also in more tropical regions of the world. In tropical regions, katydid populations are being tested by insect-eating bats, which need only follow the sound of the male's shrill call to locate their next meal.
Other than providing lunch for bat species, the katydid insect doesn't have a great deal to offer. Most gardeners find that katydid damage is minimal and many enjoy their mating song so they let them live in peace. However, in the U.S., there are some fruit growers who would appreciate the bat-like reflex to locate and destroy the katydid.
Katydids are known for feeding on garden leaves and fruit. Most often they will not consume an entire piece of fruit, but their feeding nonetheless damages the crop, resulting in discolored scar tissue and misshapen growth. Young katydids, called nymphs, typically do the most damage. Nymphs resemble full-grown katydids, but have no wings and a black and white band pattern on their long antennae.
In Florida, katydid nymphs are known for snacking on the leaves of citrus trees and less often on the actual fruit peels, creating unsightly blemishes and endangering the health of the tree overall. The veined wings of the katydid even resemble citrus leaves, providing them with camouflage as they dine during the mid to late morning hours.
Gardeners and fruits growers who are experiencing problems with katydids have several options when it comes to eliminating these pesky songsters. One natural option is called cultivation. After their late summer courtship Katydid females lay their eggs in the soil or in surrounding plant tissue where they will be hatched in the spring. By cultivating the soil throughout the spring months, growers can greatly reduce the number of young nymphs that survive the hatching process. Cultivating the soil not only affects the temperature for newly hatched katydids, but also destroys host plants that are vital to their early survival. Disking and chopping will also destroy many nymphs, considering that they are too young to seek protection on nearby citrus trees or plants.