JANUARY
1993

 

 

 

By
Tom Turpin
 
Professor of
Entomology
Purdue University

 

 

 

 

 

01-14-93

Insects Have Good Taste

 

Both humans and insects have taste — a sense of taste that is!

Scientifically, taste is sometimes called contact chemoreception. That means organisms have specialized cells that detect specific chemicals on contact. In humans those chemoreceptors are located in the mouth and are called taste buds. When we get a substance in our mouths, chemoreceptors tell us if it is sweet or bitter or salty.

Many insects also have chemoreceptors in their mouths so they, like humans, can taste their food. Some insects also have developed a sense of taste on other parts of their bodies.

For example, grasshoppers and cockroaches have protrusions of their mouthparts called palps. Palps are antennae-like structures with taste cells located in the tips. When a grasshopper encounters a potential food source, the palps come into contact with the material and gather a little taste. It's equivalent to a human licking a scoop of ice cream prior to taking a bite.

In honey bees and some wasps, the sense of taste is located in the tips of the antennae. This allows the insect to detect sweetness of a substance prior to consuming it.

Considerable work has been done comparing the ability of humans and honey bees to detect sweet substances. The famous entomologist Wigglesworth found that of 34 substances tested, humans thought 30 were sweet. Honey bees on the other hand responded to only nine of the substances. All substances determined to be sweet by the honey bee were available in nature. It appears that artificial sweeteners will not fool a bee!

Having the sense of smell in their antennae allows some parasitic insects to trail a potential host. For instance, a small parasite of cockroaches uses its antennae to trail the roach. By tapping the antennae on the surface it can track a roach much the same way a dog would trail a rabbit.

Some butterflies and flies have their sense of taste located on their feet — an interesting adaptation to tasting one's food. Butterflies use their feet to determine if the plant on which they stand is a potential host plant for their offspring. If it is, the female will deposit an egg on the plant.

Flies use the sense of taste in their feet to determine if they are walking on something edible. When a fly detects that it is standing on food, it will extend its mouth parts and begin to eat. So, when flies are walking around on our food they are just doing a taste test!

Too bad we humans don't have taste buds on our limbs like flies. Then we wouldn't have to lick the food off our fingers to determine whether or not we liked the taste.

 

 

Writer: Tom Turpin
Editor: Andrea McCann