Some insects are helpful. For example, you may know that the bee population is on the decline, and that this has serious consequences for our food chain. Entomologists want to understand the cause and consequences of the decline because this free pollinating service has a direct connection to our agricultural economy — to the tune of $15 billion [source: Holdren]. Bees and other insects are responsible for pollinating many of the crops we depend on, like most nut and fruit species.
On the other hand, many bugs are responsible for the destruction of crops. An obvious example is the damage done by an insect feeding on a plant's fruit, roots or body. For instance, a cucumber beetle's appetite does not discriminate. Adult cucumber beetles eat the fruit, leaves, shoots and blossoms of their favored plant, while their larvae prefer to munch on a cucumber's roots. Insects like aphids can also introduce viruses, infections and diseases to crops, leading to widespread devastation.
And to make this relationship even more complicated, in the early 20th century we developed chemical pesticides to mitigate the devastation of the problem insects. But the real problem is self-imposed: In destroying harmful insects, we also destroy the beneficial ones — much like chemotherapy kills cancer cells but also wipes out healthy cells and tissues. If entomologists can learn how to effectively target harmful pests, the beneficial insects could have a chance at restoring a balanced ecosystem.
Insects are not just a problem in the field. They also invade stored foods, eating and/or nesting in a cozy silo of wheat or in that forgotten box of Bisquik in the back of your pantry. Of course, a bug's interest is not limited to the vegetarian. Some species of blowflies spend their first weeks of life in the flesh of their host, living off the surrounding meat. Fleas and ticks can cause anemia, while horn flies target cattle and can consume up to a pint of blood every day. Entomologists help us understand insects' life cycles and behaviors, which in turn helps us protect our own food supply and prevent foodborne illnesses.