Header image
Enter a name
Lateral view of a Male Baetis (Baetidae) (Blue-Winged Olive) Mayfly Dun from Mystery Creek #43 in New York
Blue-winged Olives
Baetis

Tiny Baetis mayflies are perhaps the most commonly encountered and imitated by anglers on all American trout streams due to their great abundance, widespread distribution, and trout-friendly emergence habits.

Dorsal view of a Skwala (Perlodidae) (Large Springfly) Stonefly Nymph from the Yakima River in Washington
This Skwala nymph still has a couple months left to go before hatching, but it's still a good representative of its species, which was extremely abundant in my sample for a stonefly of this size. It's obvious why the Yakima is known for its Skwala hatch.
27" brown trout, my largest ever. It was the sub-dominant fish in its pool. After this, I hooked the bigger one, but I couldn't land it.
Troutnut is a project started in 2003 by salmonid ecologist Jason "Troutnut" Neuswanger to help anglers and fly tyers unabashedly embrace the entomological side of the sport. Learn more about Troutnut or support the project for an enhanced experience here.

Stonefly Species Allocapnia mystica (Little Snowflies)

Where & when

In 57 records from GBIF, adults of this species have mostly been collected during March (35%), December (19%), January (19%), February (18%), and November (7%).

Species Range

Identification

Source: Larvae Of The Winter Stonefly Genus Allocapnia (Plecoptera: Capniidae) In Mississippi, Usa

Diagnosis. The absence of erect tergal bristles at midlength (Fig. 16) will distinguish larvae of this species from all but those of Allocapnia aurora among Mississippi species. The truncate posterior margin of the developing male 10 th tergal lobe (Fig. 15) will distinguish these species.

Physical description

Most physical descriptions on Troutnut are direct or slightly edited quotes from the original scientific sources describing or updating the species, although there may be errors in copying them to this website. Such descriptions aren't always definitive, because species often turn out to be more variable than the original describers observed. In some cases, only a single specimen was described! However, they are useful starting points.

Source: The Winter Stoneflies (Plecoptera: Capniidae) Of Mississippi

Male epiproct. Upper limb of epiproct long, conspicuously angled near mid-length, ending in a broadly rounded tip (Fig. 19). Apical half of upper limb covered with short, posteriorly directed, appressed spines; a narrow, median groove divides apical section of upper limb (Figs. 18, 20). Tip of upper limb has an irregular cluster of short hairs extending beneath the epiproct for about 1 / 8 th of its length. In lateral aspect, upper limb only slightly inflated at apex and lower limb bears deep, subapical notches and a small downturned tip (Fig. 19). Male tergal process. The relatively wide and thin 8 th tergal process forms a shallow chevron shaped, and mesally notched projection in dorsal aspect. The small notch separates a pair of narrowly divided, thin knobs; these knobs are covered with scale-like tubercles over most of surface (Figs. 21 - 22).

Female subgenital plate. Abdominal sterna 7 and 8 completely separated by membrane. Posterior margin of subgenital plate typically produced as a narrow lobe; anterior margin of sternum 8 without small lobes (Figs. 23, 61). Source: New Records Of Winter Stoneflies (Plecoptera: Capniidae) In Mississippi


Start a Discussion of Allocapnia mystica

Stonefly Species Allocapnia mystica (Little Snowflies)

Taxonomy
Species Range
Resources
Troutnut.com is copyright © 2004-2024 (email Jason). privacy policy