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Predators and Prey

by Valerie (June 9, 2000)
revised August 24, 2003
immature assassin bug eating sawfly
While it's nice to see beautiful flowers and lush foliage in a garden, I find the dramas played out by the fauna to be much more absorbing. Every animal in the garden is either eating the plants, eating another animal, being eaten, or cleaning up the ecosystem by eating whatever is left over. Every so often I get the chance to see predators attack or eat their prey, and, even more infrequently, I get to photograph it.

adult assassin bug eating winged ant
Photographing certain animals is tricky because they have very good eyesight (how else would they be able to hunt?) and when they see something as big and strange as a camera lens heading their way, their first reaction is to slip around to the other side of the leaf or branch and hide. The assassin bug nymph (Zelus renardii), pictured above was uncomfortable with being photographed, but the soldier fly was fairly large and heavy, making a getaway with the prize nearly impossible. The adult assassin bug of the same species at right has caught a winged ant. We have quite a few types of true bugs in our yard and assassin bugs are also numerous. They usually hide on leaves or twigs and wait for prey to get close.
argiope spider eating grasshopperargiope spider eating blow fly

One of the most conspicuous predators is the spider. Sometimes we have the large argiope female spiders (Argiope aurantia), along with their tiny male suitors, in our yard. They are also known by other names such as garden spider, writing spider, or banana spider. Because they build a web, once they decide on a place to stay we can be sure of finding them in that vicinity all summer. The spider in the photo at left made her web by our front door, right over the doorbell. For a couple of months, everybody who came to the door knocked. She is feasting on a grasshopper. The spider at right has caught a fly. Both are females, but the one at left is mature while the other is only about half grown. As the spiders increase in size, so does their capability for large prey. Small spiders have flimsier webs and so they tend to break when a large insect hits them. Large spiders can produce a web so strong that it can hold small birds, even though the spiders are too small to take advantage of such a feast. green lynx spider eating honeybee

The green lynx spiders (Peucetia viridans) here in Texas are a very large species, with females reaching a length of about an inch. They actively hunt, but seem to have preferred territories, often around flowers. Their brilliant green color makes them hard to see in dense foliage and they easily ambush prey, here a fly and a honeybee. They are also secure enough in their camouflage that they don't try to hide when they are approached, making them one of my favorite photographic subjects. green lynx spider eating fly

crab spider eating caterpillar and waiting in ambush in a daffodil
One of the smaller spiders that I can observe closely is the crab spider (Misumenoides sp.). These colorful little arachnids usually stake out flowers, where they wait with open arms for an unsuspecting bee or fly. The one pictured here is in a daffodil and does not have the best of manners, as it is hunting with its mouth full. The spider is snacking on a miniscule caterpillar, holding it with small appendages near its mouth, while waiting in ambush position with legs spread wide open to catch the next course. young praying mantis eating yucca plant bug

The biggest insect predator we have is the praying mantis (Stagmomantis sp.), which live all over our yard. In this photo, the mantis is finishing off a meal of a yucca plant bug, a large dark brown insect that is quite common in our gardens. There are two kinds of praying mantises that live in our yard: a brown, small type in which the females have no wings, and a larger, longer bright green species with obvious wings. The mantis shown here is a young specimen and hasn't developed its wings yet.

It seems that most predators that lie in ambush do so upsidedown. All the spiders in their webs commonly orient that way and most of the praying mantises that I've seen have their heads down. Perhaps it is easier to grasp heavy prey while hanging, than to hold it up the other way, or an attack from above is more effective with flying insects.

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