Diario de bclaridge

The following are some notes on the Ichneumon of Utah. I would like to do a review of the species in Utah (or some similar area) at some point but that may be a few years off.

Ichneumon Linnaeus, 1758 is a massive genus with 903 species worldwide and 160 in North America. In Utah, there are only 4 described species.

Ichneumon creperus Cresson, 1867
Ichneumon longulus Cresson, 1864
Ichneumon pedalis Cresson, 1864
Ichneumon placidus Provancher, 1875

In neighboring Colorado, however, there are 29 recorded species. Undoubtedly, many of these are also present in Utah but have gone unrecorded due to the great lack of work on western ichneumonines. Gerd Heinrich in the mid 20th Century published on a handful of western ichneumonine genera, but the most substantial work was done by Ezra Cresson in the late 19th Century. So due to the lack of any modern taxonomic works, our knowledge of Ichneumon in the West is spotty at best.

In my personal collection, I have at least 23 unknown species based on females. I also believe that Ichneumon ambulatorius and Ichneumon devinctor are present in Utah as well. I'm sure that a decent number of those are already described but IDing them would require comparing them to Cresson type specimens in Philidelphia. Perhaps 5-15 of the 23 are undescribed.

So far, my specimens have come from several years of Malaise trapping in Logan Canyon and from Dan Cavan who has done a lot of collecting in central Utah. The majority of specimens in the USU collection are from northern Utah. Besides that, the rest of the state is massively under collected, especially southern Utah. From the limited material I have seen from around the Pine Valley Mountains, it's an entirely different ichneumonine fauna than north or central Utah. The only time I collected in Manti-La-Sal National Forest I collected a species not found in northern Utah, so that makes me curious about how much species turn-over there is along a north-south transect across the state or how well the species distributions correspond to the WWF ecoregions of North America (https://www.worldwildlife.org/publications/terrestrial-ecoregions-of-the-world). Even between Logan Canyon and central Utah there are hardly any species (just this one: https://www.inaturalist.org/observations/106353165) in common.

This post will be updated as I get new species/ specimens from Utah.

There are 66 species of Cratichneumon known from North American but only two known from Arizona, Cratichneumon arizonensis (Viereck, 1905) and Cratichneumon russatus (Cresson, 1877). Cratichneumon arizonensis has only been recorded from Arizona, while C. russatus is widespread throughout the western U.S. and Canada and is also fairly common. There are at least an additional 6 undescribed species in Arizona, mainly the mountains in the southesast. I'm currently getting started on an paper that would include descriptions of the new species, a key to the Cratichneumon of Arizona, and high-quality images of each species.

Right now, I am in the initial stages of gathering specimens (both from institutions and specimens donated to me), databasing specimens (in a custom filemaker pro database) and associating sexes. I do have about 6 species, including the two described species, that I have delimited morphologically and where the sexes can be unambiguously associated. I'm currently working on their descriptions for those species. I might have to use genetic data to associate some of the species where sexual dimorphism is more exteme. The major challenge is a lack of specimens for some species which hinders both sex association based on morphology or genetics.

This paper would be part of my larger goal of describing and popularizing the biodiversity of Ichneumoninae in North America. For me, it's exciting but unfortunate that these usually large, colorful wasps are so poorly-known. There are probably several hundred undescribed species in the western U.S and many of the described ones haven't been documented since their original descriptions in the late 19th or early 20th centuries. A further issue is that a majority of species throughout NA (including the eastern U.S. and canada) aren't adequately documented, both in terms of their distribution or being identifiable by non-experts which are few. This makes it hard to work on their taxonomy, biology, behavior, ect. and lowers public and scientific interest in them.

I know the typical iNat user is focused on field observations, but I hope this post highlights how important collecting specimens still is. My idea for this project came from pinning samples sent to me by a coleopterist in SE Arizona. I then checked the USU collection and found additional specimens which are mainly from the '60s and 70's and a not very specific location. Unfortunately, most other institutional collections aren't very useful to me because ichneumonids aren't usually collected or mounted, or if they are then they aren't sorted and available to be loaned. So for this project, a single coleopterist collecting in SE Arizona will be supplying the highest-quality specimens that will be used for any possible genetic work and as holotypes. For a longer-term project on the Ichneumon of Utah (or something similar), an amateur coleopterist, Dan Cavan, will be providing the vast most of the specimens and from localities that hadn't been sampled before. Given that he's so important to the project and will probably do some targeted collected, I would like to have Dan as a coauthor on the paper.

If anyone would like to help out with collecting Cratichneumon in Arizona for this project or collecting ichneumonids in other areas, it would be a great help!

Regardless, I hope this post was interesting for anyone who might be curious about taxonomic/ biodiversity research.

Edit:
Just for fun, here is a choropleth of Cratichneumon species richness by state. It's a continuous scale with pale yellow being a single species and deep red being 25 species. Grey indicates there are no recorded species.