Currently in North America, only one species of this genus is known. McCafferty and Meyer (2007) verified the presence of this species in California. This is a weird-looking species that lives in an atypical habitat for a mayfly. Day (1956) did key the adults to genus, but also stated Pseudiron did not occur in California. Pescador (1985) is the paper to use for a complete description of adults and larvae.

Pseudiron centralis McDunnough

Type Locale:  Kansas

California Distribution: Sacramento, Yolo

Adult Description: McDunnough (1931) described the species based on an adult female from Kansas, but use Pescador (1985) for a description of the male, including figures of the wings (Figs. 1 and 2) and male genitalia (Fig. 5).

Larval description: Pescador (1985) provided the most complete description, including figures of the mouthparts (Figs. 6-12) and SEM images of the distinctive claws (Figs. 13-16). I recommend Fig. 406 in Edmunds et al. (1976) for a full body illustration of the larvae. This is the best illustration of the larvae I have seen. Even though the figure looks proportionately wrong (the legs look too long), this is exactly what this species looks like.

Identification Notes: The long claws and unique habit should allow for easy identification.

Ecological notes: Much has been written about the ecology of this species [see, e.g., Soluk and Craig (1990), McCafferty and Provonsha (1986), Stagliano (2016)], and its habitat of living in shifting sandy portions of rivers, a habitat not amenable to most aquatic insect species. Collecting in these areas, especially in large rivers such as the Sacramento River, is difficult and can be dangerous. In addition, one can’t just use a kick net to capture this species. Stagliano (2016) described using large dip nets in Montana rivers.

References:

Edmunds, G. F., Jr, S. L. Jensen, and L. Berner. 1976. The mayfies of North and Central America. Univ. Minnesota Press, Minneapolis. 330p.

McCafferty, W. P. and M. Meyers. 2007. Insecta, Ephemeroptera: Transcontinental range extension in western North America. Check List 3: 51-54.

McCafferty, W. P. and A. V. Provonsha. 1986. Comparative mouthpart morphology and evolution of the carnivorous Heptageniidae (Ephemeroptera). Aquatic Insects 8: 83-89.

Pescador, M. L. 1985. Systematics of the Nearctic genus Pseudiron (Ephemeroptera: Heptageniidae: Pseudironinae). The Florida Entomologist 68: 432-444.

Soluk, D. A. and D. A. Craig. 1990. Digging with a vortex: flow manipulation facilitates prey capture by a predatory stream mayfly. Limnology and Oceanography 35: 1201-1206.

Stagliano, D. M. 2016. Mayflies (Insecta: Ephemeroptera) of conservation concern in Montana (status updates and management needs). Western North American Naturalist 76: 441-451.