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.)
All of the wasps were reared from caterpillars collected in Area de Conservacin Guanacaste (ACG), a biological reserve in northwestern Costa Rica. A decades-long ecological inventory of the area conducted by University of Pennsylvania ecologists Daniel Janzen and Winnie Hallwachs revealed that the wasps are extraordinarily specific to the caterpillar hosts they attack.
More than 90 percent of the wasp species were found to target only one or a very few species of caterpillar, out of more than 3,500 caterpillar species sampled in ACG.
More than 70 percent of the species first identifi
|Contact: Diana Yates|
University of Illinois at Urbana-Champaign