Now You See It…Soon You Won't?

The koa bug, the largest true bug (scientists call only some buggy insects true bugs) in the Hawaiian Islands, comes in four glittering metallic colors: green with red markings; red with green; yellow; and the rarest of all, blue.

Unfortunately, koa bugs of any color are getting scarce. Forty years ago, experts tried to control a pest insect, the southern green stink bug, by bringing to Hawaii flies and wasps they thought would prey on it. While the flies and wasps killed the stink bugs and their eggs, the koa bug and its eggs proved just as delicious—and defenseless. Now, experts fear that the koa bug may become extinct.

So this pretty creature is also a warning: “natural” pest control can be just as destructive as the chemical kind. Just ask a koa bug—if you can find one.


  • bug: A kind of insect that has mouth parts used for piercing or sucking. Some bugs have four wings, and some have none.

Back to Top


  1. In Lesson 2, you read about defensive adaptations that have occurred in various species of animals. Most adaptations are slow to happen, often taking thousands or tens of thousands of years. Humans often think they are solving a problem when they bring a non-native species into an area to control another species. Why do you think it is a problem to introduce in a short time period a new predator, such as flies and wasps, to an environment? What happens to the native bugs, such as koa bugs? Find another example of a non-native species being introduced into a new environment. What effect does the non-native species have on the native plants or animals? Write a short paragraph explaining why introducing a non-native species is sometimes harmful. Include information about the non-native species you chose and its effect on the native plants and animals.