Ichneumon of Utah

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.

Posted on March 7, 2022 10:21 PM by bclaridge