Common garden katydid fact sheet | Field of Mars EEC

What are common garden katydids?

The common garden katydid (Caedicia simplex) is a leaf-mimicking insect in the cricket and katydid group (Order Orthoptera). It is often active at night and spends the day hidden among leaves, where its wings and body shape help it blend in like a small green leaf. Katydids have very long, fine antennae and powerful hind legs that let them jump quickly if they are disturbed.

A common garden katydid.

Adult common garden katydid uses leaf camouflage to hide among plants.

Where do common garden katydids live?

Common garden katydids live among foliage and are found anywhere trees and shrubs grow, including eucalypt forests, parks and gardens. Because they are great at camouflage and often move at night, you can have katydids nearby without noticing them. A torch walk after dark is one of the best ways to spot them on leaves and stems.

Katydids live anywhere trees and shrubs grow.

What do common garden katydids eat?

Adults and nymphs are mainly plant-eaters. They feed on young leaves and petals and may also nibble seeds, fruit, nectar, pollen and occasionally insects. This mix of foods can help them survive in bushland and gardens where different plants flower and grow at different times of year.

Common garden katydids are mainly herbivores.

How do common garden katydids make sound and hear?

Male katydids sing on warm evenings by rubbing their wings together to make a soft chirping call that helps attract a mate. Some katydid calls are too high-pitched for people to hear clearly. Katydids don’t have ears on their heads—instead, they have a hearing organ (a tympanum) on each front leg, just below the “knee.”

Katydids hear using a tympanum (hearing organ) on each front leg.

What adaptations do common garden katydids have to help them survive?

Common garden katydids have several adaptations that help them survive in bushland and gardens. Their wings and body are shaped like a leaf, and their green colouring helps them camouflage among foliage so predators like birds and lizards can miss them. They are mostly active at night, which reduces the chance of being seen in daylight. If they are disturbed, strong hind legs let them jump quickly to escape. Their very long antennae help them feel and “sense” their way through plants in the dark, and their hearing organs (tympana) on the front legs help them detect danger and find mates by listening for calls.

Leaf-like wings help common garden katydids blend into foliage.

What is the life cycle of common garden katydids?

After mating, the female uses a curved egg-laying tube called an ovipositor to place eggs into plant stems or onto leaves and stems. When eggs hatch, the young katydids are called nymphs. Nymphs look like smaller, wingless versions of adults and sometimes resemble black ants when they first hatch. As they grow, they moult 5 or 6 times, with wing buds getting larger after each moult until the final moult produces a fully winged adult.

Katydid nymphs develop wing buds as they grow and moult several times.

How can you help common garden katydids?

You can help common garden katydids by protecting leafy habitat. Plant and maintain a mix of native shrubs and ground cover plants, and keep parts of gardens and outdoor learning areas rich in vegetation so katydids have places to hide during the day and feed at night. Leaving some leaf litter and fallen leaves in garden beds (where it is safe to do so) also creates shelter for many insects.

Avoid unnecessary pesticide use in gardens and school grounds, because these chemicals can harm katydids and other helpful invertebrates. If you find a katydid, watch it without handling it or pulling apart its sheltering leaves. A torch walk after dark is a great time to look for katydids on plants, and you can record what you find with a photo using iNaturalist.

Common garden katydids are most active at night.

Related fact sheets

More invertebrate fact sheets

• Invertebrate fact sheets – Explore insects, spiders, worms and other invertebrates.
• Insects fact sheet – Learn the main features and life cycles of insects.
• Cricket fact sheet – Compare a close Orthoptera relative that also makes calls.
• Grasshopper fact sheet – Another jumping Orthoptera insect found in bushland and gardens.
• Praying mantid fact sheet – A predator that may hunt katydids and other insects.

Habitats and ecosystems

• Tree habitats fact sheet – Leaves, branches and bark that provide shelter and food.
• Shrub habitats fact sheet – Dense foliage where many insects hide during the day.
• Eucalypt forest fact sheet – A Sydney bushland ecosystem with trees, shrubs and ground layers.
• Field of Mars Reserve fact sheet – Local bushland habitats that support native plants and animals.

Animals that share this habitat

• Huntsman spider fact sheet – A fast predator that hunts insects on trunks, bark and walls.
• Garden orb weaving spider fact sheet – A web-building predator that catches flying insects.
• Willie wagtail fact sheet – A bold bird that chases insects in gardens and bushland.
• Tawny frogmouth fact sheet – A nocturnal hunter that eats large insects and other small animals.

Food webs and ecological relationships

• Spider fact sheet – How spiders help control insects and support food webs.
• Black house spider fact sheet – A web-building predator that helps reduce insect numbers.
• Birds fact sheet – Explore insect-eating birds and their role in ecosystems.

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