Katydids are primarily leaf-eaters. They sometimes eat other plant parts (especially flowers). They also sometimes eat dead insects, insect eggs or slow-moving insects like aphids.

What insects do katydids eat?

Though they mostly stick to plants, katydids have been known to consume smaller bugs, insect eggs, and dead insects. If you wish to treat your katydid to an insect, leave a couple of aphids in its tank. Aphids are tiny, sap-sucking insects that move very, very slowly. This makes them the perfect meal for your katydid.

Are katydids bad for plants?

Katydids are usually considered gentle insects that aren't harmful to humans. Some people consider them garden pests; however, they usually don't cause serious damage to your plants or vegetables.