FEBRUARY
2010

 

By
Tom Turpin
 
Professor of
Entomology
Purdue University

 

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02-11-10

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Materials Management and Transport by Insects

One of the things that sets humans apart from most animals is the use of materials. Indeed, throughout human history we have used materials to construct all kinds of things. Things such as houses, cars, roads, knives, forks, toys, books, microscopes, rocket ships and, well, you get the idea.

So important are materials to humans that we have university departments named for and devoted to materials engineering. There are people who are materials management specialists. And every day all kinds of vehicles made from materials are transporting materials via road, rail and air. Yes, humans and materials go together like, or so song writers Van Heusen and Cahn wrote, "love and marriage, and a horse and carriage."

While the intensity and value of the human and materials relationship is obvious, humans aren't the only animals that put materials to use. Birds commonly employ materials, mostly of plant origin, to build nests. A few species of mammals also procure plant materials to make burrows a little homier. Even a few types of insects gather, transport and use materials as food or for nest construction.

Food is probably the material most often transported by insects. Indeed, many types of wasps and hornets feed their young on insect or spider prey. The adult wasps hunt for prey, which are captured, killed, or paralyzed, and carried to the nest. In some cases the prey insects are chewed into pieces and fed to the waiting larvae. In other cases the paralyzed prey are placed in nest cells along with an egg that, upon hatching, will have enough stored food to feed it to maturity.

Different types of insects feed on different types of prey. For instance, some wasps are called spider wasps because they provision their nests with spiders. Such wasps frequently construct their nests out of mud and have become known as mud daubers. There are wasps that feed on leafhoppers, and wasps that feed on caterpillars. Some wasps, such as the familiar yellow jackets and bald-faced hornets, feed on almost any type of insect prey.

When the insect prey of a wasp is small or is chewed up prior to transport, we hardly notice the insects carrying the food materials to the nest site. However, when the prey item is large, the wasp lugging the food home is quite a sight. Such is the case with one of the largest wasps in North America, the cicada killer. Cicada killer wasps, as their name suggests, feed on cicadas. The female adult cicada killer will catch and paralyze a cicada by stinging it. The wasp then clutches the cicada in its legs and wings its way to its nest, a burrow in the ground. This is a great example of an insect engaged in material transport, similar in relative scale if not in actual size to a 747 airplane transporting the space shuttle.

Probably some of the most conspicuous of the material transporters among the insects are bees. All bees carry pollen as food for themselves or their larvae. Many bees have special structures called pollen baskets to facilitate pollen transport. Social bees, the honey bees and the bumble bees, also carry nectar collected from flowers. Honey bees transport water for use in cooling their homes in times of heat stress.

A few wasps and some bees carry plant material to utilize in fashioning dividing walls in their nests. Leaf-cutter bees and grass-carrying wasps get their names because of the habit of acquiring those specific materials for wall building.

Ants also carry stuff around. These insects are notorious for carrying food items such as purloined material from our kitchens or picnics, prey insects, or plant seeds. Ants also carry waste materials out of the nest.

Certainly the bees, wasps and ants are proficient at materials management, but other insects also get in on the act. Termites chew up wood and carry it back to the nest. Dung beetles make balls of mammal dung and transport the balls by rolling them along the soil's surface. The water-dwelling caddis fly larvae gather twigs and stones to fashion into cases in which they live.

When it comes to materials management and transport, humans are the undisputed champions of the animal world. However, whether we want to admit it or not, some insects perfected the activity long before we humans came up with the idea.

 

 

Writer: Tom Turpin
Editor: Olivia Maddox