Parasitic Wasps Are Comprised Of More Species Than Any Other Insect Family

Which type of insect is the most species-rich in the entire insect kingdom? Some of the earliest insects to appear on earth continue to exist today. These super-ancient insect species are typically the most species-rich. These insects include termites and cockroaches. Praying mantises are also well known for being a species-rich insect. However, none of these insects can compare to beetles since beetles have long been recognized as the most species-rich group of insects. Now researchers are suspecting that their longheld assumptions concerning beetles may not be true. So far, scientists have documented three hundred and fifty thousand beetle species. This massive number dwarfs all other insect families. Although this is a large number, parasitic wasps are now being considered the most species-rich insect, and not beetles.

The belief that beetles comprised the greatest amount of species may have originated as a bias against other insects. For example, beetles are often picturesque and relatively large insects that make for great collectors items. Also the bodies of dead beetle specimens do not degrade as rapidly as other insect species. Once a beetle’s body dries out, it remains intact, as opposed to falling apart like most insect specimens eventually do. Even famed biologist Charles Darwin himself had a vast beetle collection that he happily showed off to guests. To put it simply, people have always been excited to learn that another beetle species had been discovered. But when it comes to tiny parasitic wasps, this excitement had always been hard to find.

Parasitoid wasps have not been studied as extensively as beetles since their tiny sizes make observation and capture difficult. One study found that the smallest parasitoid wasps on earth are no larger than two tenths of a millimeter in length. The very few studies on parasitoid wasps that exist reveal that they are more abundant in nature than previously thought. For example, in one desert habitat parasitoid wasps were up to three times more abundant than all beetle species. One mathematical model predicted that the total number of parasitoid wasp species far outnumbers beetle species. Although more research is needed on this topic, it is beginning to look like parasitoid wasps are the new kings of the insect kingdom.

Do you think that the lack of certainty about what defines a truly unique species makes the comparison between beetles and parasitoid wasps distorted?