Grasshoppers, katydids, and crickets. Oh my!

Grasshoppers, katydids, and crickets are all closely related insects in the insect order Orthoptera. It can be a little tricky to know which is which sometimes, but one easy way is to look at their antennae. Grasshopper antennae are generally shorter and even when they are very long they don't get longer than their body.

A very young grasshopper

An adult grasshopper

Katydid and cricket antennae are often longer than their bodies.

An immature katydid

An adult katydid

I don't have any good pictures of a cricket, but here is a video of one. 

Another difference between grasshoppers and katydids and crickets is that katydids and crickets rub their wings together to "sing" or chirp.  Grasshoppers rub their hind leg against their wing to "sing". If you are looking for more detailed info here is a good article by Debbie Hadley at about.com. The Orthoptera have gotten a bit of a bad rep due to the infamous nature of a few members of the group (e.g. the desert locust). However, the vast majority of grasshoppers, katydids, and crickets are not economic pests and at worst are just a nuisance. The fact is that not much is known about the behavior and feeding habits of the orthopterans that are not economic pests. They are mostly lumped into the herbivore category, but the amount of omnivory and predation that they do is probably grossly underestimated.