Katydids can look alarming up close, with their long legs and very long antennae, but they pose almost no danger to people or pets. At worst, a large one handled roughly can give a pinch about like a mosquito bite, and no venom is involved.1bigpesticides.com. News – Are Katydids Dangerous or Harmful to Humans, Pets, or Plants? In most gardens they are light nibblers that rarely cause damage worth acting on.2Wisconsin Horticulture. Katydids Citrus growers are the one group with a real reason to watch them, because katydids chew into developing fruit.3PubMed. Profile of Fork-Tailed Bush Katydid (Orthoptera: Tettigoniidae) Feeding on Fruit of Clementine Mandarins
Can a Katydid Bite or Hurt You
Katydids don’t go looking for people. They chew plants and sometimes small insects, so a bite almost always comes from picking one up or trapping it against your skin. The larger kinds are the ones able to pinch when they feel threatened. A katydid that lands on your arm or shirt isn’t going to bite unless you grab it.
Even then, a pinch from a large katydid usually doesn’t break the skin and fades quickly. Katydids carry no medically significant toxins,4bigpesticides.com. News – Are Katydids Dangerous or Harmful to Humans, Pets, or Plants? so there’s no venom reaction to watch for, unlike with a bee or wasp sting.
If you do get pinched, wash the spot with soap and water like any small scrape. A cold compress eases the brief soreness. If the skin did break, watch only for the ordinary signs of infection, such as spreading redness or warmth. A typical pinch needs no doctor visit.
Children who catch katydids may get pinched, so show them how to cup their hands gently around one. A dog or cat that eats a katydid isn’t poisoned by it. Mild stomach upset is possible, as with any bug, but uncommon.
How Much Do Katydids Damage Garden Plants
Katydids have chewing mouthparts, and most of them feed on plants.5Wisconsin Horticulture. Katydids Even so, they rarely cause significant damage to crops or ornamental plants.6Wisconsin Horticulture. Katydids You’re most likely to see feeding on garden leaves, flowers, and potted plants in late summer.7Wisconsin Horticulture. Katydids
Their feeding is also spread around. Individual katydids often eat from several different plant families.8PubMed Central. Patterns of Herbivory in Neotropical Forest Katydids as Revealed by DNA Barcoding of Digestive Tract Contents Some grass-feeding kinds prefer certain grasses but switch to many others when they need to.9Entomologia Experimentalis et Applicata. The edible katydid <i>Ruspolia differens</i> is a selective feeder on the inflorescences and leaves of grass species The result is usually a few holes across many plants rather than one plant stripped bare.
Katydid damage looks like irregular chewed holes or ragged leaf edges, and sometimes nibbled petals on showy blooms. Because they feed after dark, new damage seems to appear overnight. You won’t find the webbing, sticky residue, or clusters of droppings that some other pests leave.
A few holes don’t affect a plant’s health. Young seedlings and prized blooms are the exception, since there’s little leaf to spare. If you see several katydids on one plant night after night, especially on seedlings or prized blooms, that’s a reason to act.
Holes alone don’t identify the culprit. Slugs, caterpillars, beetles, and earwigs all do similar work. The most direct way to confirm is to go out after dark with a flashlight, since katydids hide and stay still by day. They’re green and leaf-shaped, so an empty daytime search doesn’t rule them out.
Some katydids also eat slow-moving insects such as aphids.10A-Z Animals. What Do Katydids Eat? Their Diet Explained And they are food for birds, frogs, lizards, spiders, and bats.11A-Z Animals. Katydid
The Exception Citrus Fruit
On clementine mandarins, katydids readily chew holes that turn into jagged, web-like scars.12PubMed. Profile of Fork-Tailed Bush Katydid (Orthoptera: Tettigoniidae) Feeding on Fruit of Clementine Mandarins Maturing fruit with that damage often splits and drops early.13PubMed. Profile of Fork-Tailed Bush Katydid (Orthoptera: Tettigoniidae) Feeding on Fruit of Clementine Mandarins On oranges, the scars tend to be round.14PubMed. Profile of Fork-Tailed Bush Katydid (Orthoptera: Tettigoniidae) Feeding on Fruit of Clementine Mandarins Results vary by variety, though: some mandarins get mostly shallow surface scarring with little fruit drop.15Journal of Economic Entomology. Resistance of Fruits From a Mandarin Cultivar to Feeding by Fork-Tailed Bush Katydids
Fruit damaged while small keeps growing, so a small bite becomes a larger scar as the fruit swells. The harm happens early, so the evidence often shows up weeks later, after the katydid has moved on.
The damage is also easy to misread. Katydid scars on clementines often look like caterpillar damage,16PubMed. Profile of Fork-Tailed Bush Katydid (Orthoptera: Tettigoniidae) Feeding on Fruit of Clementine Mandarins so home growers may blame the wrong insect. Finding a katydid on the tree at night is stronger evidence than the mark. Caterpillars tend to be found on leaves and are slow, soft-bodied larvae, while a katydid is a green, long-legged adult or nymph with long antennae. If chewed leaves and scarred fruit appear together with caterpillars present, caterpillars may deserve at least some of the blame.
To check a backyard tree, inspect the small green fruit in spring and early summer. Fruit dropping with chewed holes can suggest heavier feeding, though fruit drops for other reasons too. Healed scars on ripe fruit are cosmetic.
Scars affect the peel, not safety, so scarred fruit is still fine to eat; it just looks less appealing. Split fruit can rot, so pick it promptly.
Those Neat Rows of Eggs on Twigs
Katydid eggs cause no plant damage.17Private Lands Wildlife. Katydid Eggs: What Those Neat Rows on Your Twigs Really Are Scale insects can look similar, but they produce sticky honeydew and cause yellowing or dieback.18Private Lands Wildlife. Katydid Eggs: What Those Neat Rows on Your Twigs Really Are
The eggs themselves are flat, overlapping ovals in tidy rows. Scale is bumpy and scattered, and it often sits on sooty or sticky bark. Females lay the eggs with a blade-like organ at the tail.
Eggs are laid in late summer and fall, so you often notice them when leaves drop or when you prune in cooler months. Females place them on twigs, stems, and along leaf edges, often on the plants where the adults fed. They stay through winter and hatch in spring, which means a row seen in January is still alive rather than an empty case.
Leave them alone. Tiny wasps attack katydid eggs naturally, and removing them isn’t needed in a home garden.
Katydid or Grasshopper
Katydids tend to be bright green, while grasshoppers are a more earthy green.19Forest Preserve District of Will County. What’s the difference?: Grasshopper vs. katydid vs. cricket Katydid antennae are often longer than the body, while grasshoppers have short, thick antennae.20Forest Preserve District of Will County. What’s the difference?: Grasshopper vs. katydid vs. cricket Katydids often look like a leaf, with veined wings. Katydids don’t swarm, unlike some grasshoppers.
The distinction matters because grasshoppers can chew a garden much harder.
Other look-alikes are easy to rule out. Crickets are usually brown or black, and praying mantises have grasping front legs.
Where you find the insect helps too. Katydids tend to stay up in shrubs and trees, often among leaves they resemble, while many grasshoppers are found on the ground and in open grass. A katydid at a window screen or porch light at night is typical, since they’re attracted to lights after dark.
What to Do If You Want Fewer Katydids
Katydids don’t damage homes, and most homeowners who find them need no treatment.21Better Termite & Pest Control. Katydids – ID & Control Those that come indoors are usually drawn by lights, gaps, or nearby plants.22Better Termite & Pest Control. Katydids – ID & Control
Swapping bright white outdoor bulbs for warm or yellow ones makes porches less of a draw for night-flying insects. Turn off lights near doors and windows at night, or draw the curtains, so the glow doesn’t pull katydids toward the house. Check window screens for tears and door sweeps for gaps, since a katydid at a screen can slip in through a small opening. One that does get in can be carried out in a cup with a card over the top, with no pinch and no product needed.
Katydids rest by day in shrubs, trees, and tall grass and feed there at night.23Solutions Pest & Lawn. Katydid Control: How to Get Rid of Katydids So trim overgrown shrubs and rake leaf litter near the house. Mowing before grass passes about 3 inches leaves less cover.24Solutions Pest & Lawn. Katydid Control: How to Get Rid of Katydids Shrubs touching the walls give katydids a place to rest by day and then reach the house at night, so trim branches to leave a gap between plants and siding. This lowers the number near the house but won’t clear them from the neighborhood, so the goal is fewer, not none.
For plants that need protection, row covers or hand-picking keep katydids off small plants.25Vego Garden. Katydids in the Garden: Friend or Foe For hand-picking, go out after dark with a flashlight, when they feed. Cup them in a jar rather than grabbing them, and release them away from the garden or near wild areas.
If many show up on citrus while the fruit is still small, insecticidal soap, neem oil, or spinosad products are options.26Vego Garden. Katydids in the Garden: Friend or Foe Spray only the affected citrus or plants, not the whole yard, and do it in the evening to spare bees. Follow label rates and timing. Natural egg parasites usually don’t prevent damage on their own in heavily hit trees.27UC Statewide IPM Program. Katydids Management Guidelines