March 28, 2013

Speeding-up the description of species

Yesterday I was reading two different but related papers dealing with accelerating the pace of species description by taxonomists. Both were published as open access, thus the interested reader can freely download them here and here. The paper from Zookeys dealt with the description of 101 new species of weevils (Coleptera, Curculionidae) from Papua New Guinea, while the one from Frontiers in Zoology is more about how to embark oneself in this thrilling fast-pace description of species.

Those two papers, published this week, are not the first ones to propose such a fast pace. Six months ago a paper in Zootaxa described 179 new species from Thailand belonging to the braconid genus Aleiodes and proposed the term "turbo-taxonomy" for such fast and quick descriptions. I am also aware of other papers in Hymenoptera following similar approaches (for example, a series of papers from the Platygastroidea Planetary Biodiversity Inventory, and two soon-to-be-submitted papers on the braconid genera Heterospilus and Apanteles). And without doubts, there are more papers published (or being written) which describe lots of species in a relatively fast way.

This topic, very fascinating and also controversial, has interested me for the past few years. Actually, any taxonomist dealing with hyperdiverse groups should be interested in considering and evaluating any help to speed-up the pace at which species descriptions are made! 
What characterizes such efforts? Are they done by "super-humans" taxonomists? Or "super-smart" ones? Is there a magic wand that allows to generate such impressive (and massive) papers?

There are a few common things shared between those papers. The three most conspicuous are:

1) Using DNA barcodes as one of the main tools to separate species. In some cases, barcoding is THE ONLY mean used to separate species, and is even added to taxonomic keys (for example, see some couplets of the Aleiodes paper mentioned above). Barcoding is not only used to tell species apart, but also to reconstruct phylogenies and to characterize individual species (in many cases the actual barcode is included as part of the description process).

2) Relying on high resolution pictures to depict characters and illustrate species.

3) Providing only short descriptions of the species (at least relatively short compared to more "traditional" taxonomic papers). Obviously this is a result of the previous point (and a confirmation of the old adage that "One picture is worth a thousand words").

March 18, 2013

Photos of four Nearctic species of Microgastrinae

I have been too busy lately -and should continue to be that way until mid April or so. For that reason, my contributions to this blog for the next few weeks will be more limited than what I would like. 

This post is to share colour photos and basic comments on distribution and hosts of four Nearctic species of Microgastrinae, with the hope of expanding that information in the near future. It is part of a long-term effort to build a virtual library (of images, biological, ecological and taxonomic information) about braconid species parasitoids of caterpillars -in North America and hopefully beyond. As far as I know, the photos shared below are the first colour photos available for those species -if I am wrong, please let me know!


1- Glyptapanteles compressiventris. This is a widely distributed species in the Holarctic (Nearctic, Eastern and Western Palearctic). It has been reared mostly from the Lepidoptera family Arctiidae (eight hosts species recorded), with a couple of questionable records from Noctuidae and Tortricidae.
Glyptapanteles compressiventris specimen from the Canadian National Collection of Insects, Ottawa. Photo taken by Caroline Boudreault and José Fernández-Triana.

March 14, 2013

The beautiful complexity of caterpillar-parasitoid food webs

This morning the good friend and colleague Dr. Jan Hrcek sent me a copy of his last paper on caterpillar-parasitoid food webs in Papua New Guinea (PNG). In the past we had collaborated regarding some work on braconid wasps, especially microgastrines. Jan has been researching caterpillars and their parasitoids in PNG for several years and has published quite a few interesting and amazing papers on the topic.

The title of the paper that he sent me today is "Parasitism rate, parasitoid community composition and host specificity on exposed and semi-concealed caterpillars from a tropical rainforest", and was published in Oecologia. It documents parasitism rate and host specificity in a highly diverse caterpillar-parasitoid food web encompassing 266 species of lepidopteran hosts and 172 species of hymenopteran or dipteran parasitoids from a lowland tropical forest in PNG.

I strongly recommend the reading of this paper -which, unfortunately, is not open access, but I guess the interested reader could contact Jan to ask for a copy. Anyone rearing caterpillars and/or dealing with caterpillar parasitoids will find the data reported there useful. I found the comparison between parasitoids of external and semi-concealed host very telling, even though some results are not in line with some preconceived ideas -such as ichneumonid wasps being more generalists than tachinid flies. But preconceived ideas are just that, and field data may change our "old thinking" on parasitoids. This study is based in collecting almost 40,000 caterpillars in the wild, with a rearing success of more than 11,000 adult Lepidopterans and over 1,500 parasitoids (wasps and flies) which represented 12% of parasitism rate. That is certainly a sizable database to extract some valid conclusions -although it may be risky to make generalizations to the world fauna based on only one study site, but I look at this as a very valuable piece of information.

And, of course, I liked the fact that braconids, and especially Microgastrinae, are considered the most suitable group for the biological control of caterpillars (but I am totally biased here ;-)

Most importantly, it is an eye-opener to realize that there has been no resarch like this in the past. Even the most comprehensive studies rearing caterpillars in several regions of the world -Jan cites in his paper a good number of such studies- have not fully addressed the potential differences between parasitoid communities of exposed and concealed (or semi-concealed) hosts. We still know so few about this and many other related topics!

After I read Jan's paper I went to briefly check some of those past researches that he mentioned. And I spent some time analyzing the diverse approaches, merits and/or shortcomings of those studies. There are many logistics difficulties, lack of resources and time constraints that limit what we can do -especially in tropical, hyperdiverse areas... I will try to cover those topics in future posts.

It is never a simple thing this endeavour of rearing caterpillars and study their parasitoids!

March 6, 2013

Internet resources about Microgastrinae. Part IV

This is the fourth part of a series of posts discussing available, free, Internet resources on microgastrine wasps (Braconidae). The interested reader can retrieve the complete series by searching for the Tag "Internet Resources" within this blog.

The post of today will deal with a journal website: Annales historico-naturales Musei nationalis hungarici. The reason why such a site is included here is because of the amount of papers it has on Braconidae, as free pdfs. If one does a search in the journal (using "Braconidae" as keyword and searching in "all fields") it is possible to retrieve 63 papers, 60 of them downloadable as pdf documents. And at least half of those papers are about Microgastrinae.



The main reason for so many papers on Braconidae (and indeed on microgastrines) is due to the prolific work of the Hungarian braconid expert, Dr. Jenő Papp, a former researcher with the Hungarian Natural History Museum. Jenő, now retired (but still working and actively publishing at the age of 80!), has described around 750 new species of Braconidae, including 130 or so Microgastrinae. Especially important is his series of 12 papers "A survey of the European species of Apanteles..." where he dealt with the Palearctic fauna of Apanteles -which at that time included most of Microgastrinae, with the exception of Microgastrinae, Microplitis and a couple of small genera. Altogether with the work of Nixon (a British researcher, to be featured in future posts here), the papers of Papp should be consulted by anyone studying specimens in the Holarctic region -i.e. North America, Europe and temperate Asia. Thanks to the open access provided to many of those papers by the "Annales historico-naturales Musei nationalis hungarici" it is now possible to download and study Papp's work.

What I find most amazing of Jenő, a great researcher and character, is that most of his career happened during the socialism times in Hungary. As a result, it was difficult for him to access other European collections (especially those from Western Europe). However, he managed to keep publishing. And, as far as I know, he was the first braconid expert from Europe to embrace the new generic concepts of Microgatrinae proposed by Mason in 1981. Papp produced a paper in 1988 (part XI of his series on Apanteles) where he transferred the older names of European species to the new genera described by Mason.  

March 1, 2013

Updated list of Nearctic Microgastrinae (Hymenoptera: Braconidae)

This post introduces a new way I plan to use in this blog to share taxonomic information. I will start providing dynamic species lists -in the sense that data are new/current as of the date they are posted, and they will be kept updated as I post more information during the next few months.

The reader should check the page in this blog named "Species Lists". It provides updated information about species from a particular region. The first list posted includes all Microgastrinae known from the Nearctic Region (Canada, Greenland, and United States). You can access that data by clicking on the top left corner of the blog, or just by clicking  here.

A total of 338 Microgastrinae species (321 of them already described) are accounted for there, making it the most comprehensive list assembled so far for the region. Let's briefly summarize what was known before.


The last Nearctic list was published by Whitfield (1995). It included 288 microgastrines -282 when removing some questionable records: at least 5 species introduced into North America as biological control agents which are not likely to be established; and also cited Glyptapanteles longicornis as a valid species, overlooking its synonymization under G. pallipes by Papp (1983). 

During the 18 years since the publication of Whitfield's paper, 27 new species with Nearctic distribution have been described, and a handful of species already described from other regions have been recorded for North America.

For example, Fernandez-Triana (2010) provided an updated list of 225 species for Canada and Alaska, including 29 species determined only to genus level. Some of those undescribed species are also mentioned in the present list, because they are expected to be published soon (and when they are, the blog will update that information accordingly). However, I have left may more out -species that are clearly new records for the Nearctic but are not accounted for now, pending further study.