Diversity among parasitic wasps is even greater than suspected

U. of I. entomology professor James Whitfield and doctoral student Josephine Rodriguez led the taxonomic part of a multi-disciplinary study of microgastrine wasps. Click here for more information.

A tiny wasp that lays its eggs under the skin of unwitting caterpillars belongs to one of the most diverse groups of insects on Earth. Now researchers report that its diversity is even higher than previously thought.

(To see an audio slide show on the research, please go to: http://publicaffairs.illinois.edu/slideshows/Microgastrine.)

By combining ecological and genetic data with the painstaking detective work of taxonomy, the researchers have dramatically increased – nearly doubling – the estimated number of species reported of six very species-rich genera of parasitoid wasps.

The subfamily to which these wasps belong, Microgastrinae, gets its name from its tiny abdomen. The wasp itself is quite small, about the size of the lead at the tip of a pencil.

By looking at the physical characteristics (morphology) of more than 2,500 wasps, the taxonomists identified 171 provisional species of microgastrine braconid wasps. But a comparative sequence analysis of a piece of a specific gene, a technique called DNA barcoding, found that there were actually 313 provisional species.

(A provisional species is one that has not yet been given a formal scientific name, or in some cases, has not yet been found to be the same as a named species.)