Hex Mayflies
Hexagenia limbata
The famous nocturnal Hex hatch of the Midwest (and a few other lucky locations) stirs to the surface mythically large brown trout that only touch streamers for the rest of the year.
Stonefly Species Remenus duffieldi (Georgia Springflies)
Species Range
Identification
Species ID from GBIFthe Global Biodiversity Information Facility
Source: Holomorphology And Systematics Of The Eastern Nearctic Stonefly Genus Remenus Ricker (Plecoptera: Perlodidae)
Diagnosis. Remenus duffieldi is distinguished from all other Remenus species in coloration and genitalic structure. The pale pronotum and grayish wings are unlike any other species in the genus. The epiproct is most similar to Remenus bilobatus in that it has a dorsal sclerite, but in contrast, it does not greatly exceed the epiproct apex. Additionally, Remenus duffieldi is differentiated in that the epiproct is dorsoventrally flattened, tergum 9 is not divided, lacks sensilla basiconica, and the spinulae covering the basal cowl are pale. Whereas in males of Remenus bilobatus, the epiproct is flattened laterally, the 9 th tergum has a medial glabrous division, both terga 8 and 9 have mediolateral patches of sensilla basiconica and the basal cowl is clothed in dense golden-brown spinulae.
Females are distinguished by the distinctive pronotal coloration in addition to differences in the subgenital plate. In Remenus duffieldi, the subgenital plate is broadly rounded and elongate, generally, as long as, or longer than tergum 9. Whereas in Remenus bilobatus, the subgenital plate is either broadly triangular or broadly rounded and typically does not exceed the posterior margin of tergum 9.
Mature larvae of Remenus duffieldi are separable from the two other sympatric species, Remenus bilobatus and Remenus daniellae by the lack of long setae on the basal cercal segments. Remenus kirchneri also lacks long setae on the basal cercal segments, but based on presently available records, the ranges of these two species do not overlap with Remenus duffieldi occurring west of the French Broad River and Remenus kirchneri occurring to the east (Fig. 115).
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.
Description from GBIFthe Global Biodiversity Information Facility
Source: Holomorphology And Systematics Of The Eastern Nearctic Stonefly Genus Remenus Ricker (Plecoptera: Perlodidae)
(Figs. 70 – 87) http: // lsid. speciesfile. org / urn: lsid: Plecoptera. speciesfile. org: TaxonName: 607Source: Holomorphology And Systematics Of The Eastern Nearctic Stonefly Genus Remenus Ricker (Plecoptera: Perlodidae)
Male. (Fig. 70). Macropterous; forewing length 9.5 – 10.4 mm (n = 10) (Fig. 71). Body length, 7.9 – 9.8 mm (n = 10). General body color pale yellow-gold with light brown markings. Dorsum of head typical of genus (Fig. 72). Pronotum pale, covered in regularly spaced setae, with light brown rugose areas, glabrous rugosities mediolaterally (Fig. 72); anterior and posterior margins brown (Fig. 72). Abdominal terga with a narrow mid-dorsal, dusky, interrupted brown stripe (Fig. 73); terga 1 – 4 pale yellow, terga 5 – 9 pale yellow to light brown; terga darkened laterally (Fig. 73); tergum 9 lacking sensilla basiconica (Fig. 74). Hemitergal lobes short, not separated from 10 th tergum, with long trichoid sensilla and 15 – 17 sensilla basiconica on each lobe (Figs. 74 - 77). Epiproct length ~ 382 – 420 µm; width ~ 136 – 168 µm (n = 3); epiproct flattened dorsoventrally (Figs. 75, 78), clothed in appressed hair-like spinulae, and with a mediodorsal sclerite (Figs. 74, 77 – 78); epiproct widest basally; hair-like spinulae of distal ¼ splayed (Fig. 79). Mediodorsal sclerite narrow throughout its length (slightly wider at its base) and barely exceeding the epiproct apex (Figs. 77 – 80); sclerite with a dorsal hump near distal ¼ (Figs. 77 – 79); apex smoothly rounded and glabrous (Fig. 80). Paragenital plates short, rounded, or triangular (Figs. 74, 77). Basal cowl covered in dense lightly pigmented spinulae (Figs. 74 – 75).
Female. Macropterous; forewing length 10.5 – 11.1 mm (n = 10). Body length, 8.9 – 10.4 mm (n = 10). General color and morphology similar to the male. Abdominal pigment pattern usually less developed. Medial dusky stripe is faint and lateral margins are not distinctly darkened. Subgenital plate broadly rounded, elongate, lightly sclerotized, with regularly spaced setae, extending 4/5 over sternum 9, or slightly beyond the posterior margin of sternum 9 (Fig. 81); basolateral crease nearly straight or convex posteriorly, extending ~ 1/3 length anteriorly into sternum 8 (Fig. 81).
Ovum. Shape typical of genus (Figs. 82 – 84). Length 444 – 446 µm; width 340 – 355 µm (n = 3).
Larva. (Fig. 85). Body length 9.1 mm, (n = 1). Head (Fig. 86), lacinia (Fig. 87), mandibles (Fig. 88), and pronotum (Fig. 86) typical of genus. Mature male larva with a short triangular terminal process (developing epiproct) (Fig. 89), Basal cercal segments with whorls of short setae (Fig. 90).
Start a Discussion of Remenus duffieldi
Stonefly Species Remenus duffieldi (Georgia Springflies)
Species Range
Common Name
Resources
- NatureServe
- Integrated Taxonomic Information System
- Global Biodiversity Information Facility
- Described by Kondratieff, B.C. & Nelson, C.H. (1995) A review of the genus Remenus Ricker (Plecoptera: Perlodidae), with the description of two new species. Proceedings of the Entomological Society of Washington 97, 596–602.