Navigation Links
Diversity among parasitic wasps is even greater than suspected

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:

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 identified by the taxonomists were confirmed in the genetic analysis.

But the DNA barcoding also revealed that some wasps that looked alike and were once thought to belong to a single species were actually several different species, each of which preyed on only one or two species of caterpillar hosts.

"The most extreme case of overlooked diversity is the morphospecies Apanteles leucostigmus," the authors wrote. Barcoding revealed that instead of being a single species that preyed on 32 different species of related caterpillars, as was previously thought, the wasps formerly classified as A. leucostigmus could be grouped into 36 provisional species, "each attacking one or a very few closely related species of caterpillars."

"One of the messages of this paper is that you really need all of these different kinds of data in order to tell the species apart that just using the morphology alone, or the genetic data or the ecological information alone isn't enough," said University of Illinois entomology professor James Whitfield, who led the taxonomic study. "However, once the species are distinguished, anyone can use the DNA barcode to rapidly and accurately identify one of them."

"This represents microgastrine wasps reared from approximately 3,500 caterpillar species in ACG," said Josephine Rodriguez, a doctoral student and microgastrine expert in Whitfield's lab. "Since there are an estimated 10,000 species of caterpillars there, including many unsampled ones that mine inside leaves or live in fungi, this is just the tip of the microgastrine iceberg."

Whitfield credits Rodriguez, an avowed microgastrine enthusiast, with pushing the research forward in a way that helped integrate the work of three very different laboratories. She and two assistants processed more than 5,000 specimens from the ACG ecological study and shipped them to the Biodiversity Institute of Ontario at the University of Guelph for barcoding. She also worked with Whitfield and fellow former graduate student Andy Deans, who is now on the faculty at North Carolina State University, to independently identify the species based on their morphological traits.

M. Alex Smith and Paul Hebert at the Biodiversity Institute of Ontario conducted the barcoding analysis, which compared the sequence of nucleotides that spell out the barcode region of the cytochrome c oxidase 1 gene in every specimen. Significant differences between the sequences indicated that the specimens belonged to different species if those differences correlated with other morphological and/or ecological traits. In cases where the genetic data were murky, the researchers also analyzed other genes and again compared their results to the ecological and morphological data.

The new analysis, which appeared online this month in the Proceedings of the National Academy of Sciences, sheds new light on a group of insects that are already astounding in their diversity, Whitfield said.

"The family Braconidae, to which the microgastrines belong, has about 15,000 described species in the world, and it's been estimated to have 50 to 60,000 species, which is about the same as all vertebrates all fish, birds, mammals, amphibians, reptiles which is a lot!" Whitfield said. "And what we're saying is that if anything we're underestimating how many more there are."


Contact: Diana Yates
University of Illinois at Urbana-Champaign

Related biology news :

1. Coral reef fish harbor an unexpectedly high biodiversity of parasites
2. Spatial patterns in tropical forests can help to understand their high biodiversity
3. Hydrothermal vents: Hot spots of microbial diversity
4. Upper Midwest forests are losing diversity, complexity, ISU study finds
5. NAS Biodiversity and Extinction Meeting Dec. 7-8
6. How global is the Global Biodiversity Information Facility?
7. Single-largest biodiversity survey says primary rainforest is irreplaceable
8. Are current projections of climate change-impacts on biodiversity misleading?
9. GBIF making the search for biodiversity research resources easier
10. New study finds biodiversity conservation secures ecosystem services for people
11. Study of bear hair will reveal genetic diversity of Yellowstones grizzlies
Post Your Comments:
Related Image:
Diversity among parasitic wasps is even greater than suspected
(Date:10/29/2015)... health pioneer, Joseph C. Kvedar , MD, describes ... wellness, and the business opportunities that arise from it ... Healthy Things . Long before health and wellness ... vice president, Connected Health, Partners HealthCare, was creating a ... the hospital or doctor,s office into the day-to-day lives ...
(Date:10/27/2015)... Oct. 27, 2015 In the present market ... concern for various industry verticals such as banking, healthcare, ... the growing demand for secure & simplified access control ... such as hacking of bank accounts, misuse of users, ... such as PC,s, laptops, and smartphones are expected to ...
(Date:10/26/2015)... 26, 2015 ... adds Biometrics Market Shares, Strategies ... well as Emerging Biometrics Technologies: Global ... its collection of IT and Telecommunications ... --> . ...
Breaking Biology News(10 mins):
(Date:11/24/2015)... 2015  PDL BioPharma, Inc. (PDL) (NASDAQ: PDLI ) ... president and chief executive officer, will present at the 27 ... New York City . The presentation will ... 2015 at 9:30 a.m. EST. and ... at least 15 minutes prior to the presentation to allow ...
(Date:11/23/2015)... CHICAGO , Nov. 24, 2015 Women with ... screening CT exams face a higher risk of lung cancer ... being presented next week at the annual meeting of the ... --> --> Lung ... are classified as solid or subsolid based on their appearance ...
(Date:11/23/2015)... VA (PRWEB) , ... November 23, 2015 , ... Noblis, ... McCarthy , former Director, Plans and Programs, National Geospatial Intelligence Agency (NGA), has joined ... us with an incredibly distinguished career in the intelligence community and the private sector,” ...
(Date:11/23/2015)... 2015  CryoLife, Inc. (NYSE: CRY ), a leading ... vascular surgery, announced today that it will participate in the ... Wednesday, December 2, 2015 at The New York Palace Hotel ... Pat Mackin , President and Chief Executive Officer. ... --> A live webcast of the Company,s ...
Breaking Biology Technology: