**Stonefly Species Hesperoperla pacifica (Golden Stone)**

Mayflies

Caddisflies

Stoneflies

Taxonomic Navigation -?-

Kingdom Animalia (Animals)

» Phylum Arthropoda (Arthropods)

» Class Insecta (Insects)

» Order Plecoptera (Stoneflies)

» Family Perlidae (Golden Stones)

» Genus Hesperoperla (Golden Stones)

» Species pacifica (Golden Stone)

Common Names

Match	Common Name
	Golden Stone
	Big Golden Stone
	Willowfly

Pictures Below ↓

This is page 2 of specimens of Hesperoperla pacifica. Visit the main Hesperoperla pacifica page for:

The behavior and habitat of Hesperoperla pacifica.

Pictures of 8 Stonefly Specimens in the Species Hesperoperla pacifica:

Specimen Page:12

Male Hesperoperla pacifica (Golden Stone) Stonefly Adult

View 1 Pictures

Collected June 17, 2011 from the Grande Rhonde River in Washington
Added to Troutnut.com by Bnewell on June 26, 2011

Hesperoperla pacifica (Golden Stone) Stonefly Adult

View 14 PicturesI collected this specimen as a nymph and had it in line to be photographed, but it emerged inside my holding container before I got the chance. However, I was able to get some interesting photos of the very freshly-emerged adult that really demonstrate how strikingly colors can change within a few short hours after emergence. The before-and-after pictures are combined here under a single specimen since they portray the same individual at different times within the same stage.

Based on the identification of another specimen from the same date/site, I'm calling this Hesperoperla pacifica.

Collected July 2, 2019 from the Gallatin River in Montana
Added to Troutnut.com by Troutnut on July 18, 2019

Hesperoperla pacifica (Golden Stone) Stonefly Nymph

View 9 PicturesID notes from the microscope: The occiput (Occiput: The back of the head.) has a sinuate, irregularly spaced spinule row.

Collected August 3, 2020 from the East Fork Big Lost River in Idaho
Added to Troutnut.com by Troutnut on August 19, 2020

Female Hesperoperla pacifica (Golden Stone) Stonefly Adult

View 12 Pictures

Collected August 1, 2020 from the Henry's Fork of the Snake River in Idaho
Added to Troutnut.com by Troutnut on August 17, 2020

Hesperoperla pacifica (Golden Stone) Stonefly Nymph

View 13 Pictures

Collected March 19, 2019 from the South Fork Snoqualmie River in Washington
Added to Troutnut.com by Troutnut on June 14, 2019

Specimen Page:12

Jargon Defined:

Emergence: The transformation of a nymph or pupa into the adult winged stage of an insect. The term may refer to the emergence of an individual, or the daily or yearly event in which all individuals of a species emerge.

Nymph: The juvenile, underwater stages of mayflies, stoneflies, dragonflies, and damselflies and other aquatic insects whose juvenile stages are covered by hard exoskeletons. The word can also refer to the fishing flies which imitate these creatures, in which case it is used as a blanket term for flies imitating any underwater stage of an invertebrate (except for crayfish and leeches).

Occiput: The back of the head.

Useful References:

Swisher, Doug and Carl Richards. 2000. Selective Trout. The Lyons Press.