Predator avoidance in insects

I have posted about predators a couple of times, so I thought I would give prey their due. This post is mostly about insects because I have lots of insect images, but one could come up with vertebrate examples of these phenomena as well. Lots of animals are both prey and predator, but for those that are primarily prey and not predators, evolution has crafted a bewildering array of predator avoidance mechanisms. One of the more straightforward of these mechanisms is to blend into the environment, by being cryptic, like this chrysalis

or this grasshopper

or this katydid

or this caterpillar

or this moth

 

Another way is to look like something you are not, like this caterpillar, which looks like the head of a snake

Some species cover themselves with some sort of protection, like the spittlebug

or the tent caterpillar

 

Then there are those that advertise the fact that they taste bad, like the Monarch butterfly

or the milkweed bug

that feed on milkweeds whose sap contains cardiac glycosides (which evolution has designed to protect the plant from herbivores, but that will be the subject of another post)

You can also advertise the fact the you are dangerous, like the assassin bug, which has a painful bite

The bombardier beetle explosively emits a foul smelling and tasting chemical

 

Some species bribe other species to protect them, like these aphids that are tended and guarded by ants

Then there are those that do active predator defense, like ants, honeybees, and paper wasps.

Of course, predator avoidance is not a sure thing. For example, if one dissects a fecal pellet from a collared lizard at Ten Acre Rock in southern Oklahoma, one will almost certainly find exoskeleton parts of Trimerotropis saxatilis, the cryptic grasshopper above.

The Collared Lizard (the state reptile of Oklahoma):

A collared lizard fecal pellet:

A head capsule of Trimerotropis saxatilis from the fecal pellet: