Ephemeroptera: Ephemerellidae of Gunnison County, Colorado
Drunella grandis grandis(Eaton) 1884
Western Green Drake, Green Drake
Updated 22 Jan 2019
The big mayfly is a Drunella grandis, the other big guy in the upper right corner is a Drunella doddsii, the little mayfly near the top is a Baetidae or small minnow mayfly. They were photographed and returned to West Brush Creek in early August 2008.
East River, Cimarron Creek, Myers Gulch, Curecanti Creek, Blue, Creek, Soap Creek, West Elk Creek, East Elk Creek, Steuben Creek, Beaver Creek, Gunnison River (Argyle and Edmunds, 1962). Persons interested in the species will also find it in the Taylor River, Coal Creek, Copper Creek, East River, Brush Creek, Cement Creek and Slate River as well as many other streams. Widespread in our area and the western United States.
Drunella grandis grandis is one of three subspecies of Drunella grandis in the United States. D. grandis grandis is found in the central and southern Rockies. Drunella grandis flavitincta is found in the Pacific Northwest, and Drunella grandis ingens is found in the Northern Rockies as well as the Sierra Nevada Range.
On this website:
Allen,RK and Edmunds,GF 1962 A revision of the genus Ephemerella (Ephemeroptera: Ephemerellidae). V. The subgenus Drunella in North America. Miscellaneous Publications of the Entomological Society of America 3, 147-179. PDF
Argyle,DW; Edmunds,GF 1962 Mayflies (Ephemeroptera) of the Curecanti Reservoir Basins Gunnison River, Colorado. University of Utah Anthropological Papers 59 8, 178-189.
Discussed as Ephemerella grandis grandis. Quote from page 186: "This species was quite common in most streams in the area. The emergence of this species concludes in the first part of July with the principal emergence taking place during the last two weeks in June. The nymphs were taken in riffle areas, generally close to the bank."
Ball,SL; Hebert,PDN; Burian,SK; Webb,JM 2005 Biological identification of mayflies (Ephemeroptera) using DNA barcodes. Journal of the North American Benthological Society 24 3, 508-524.
They include Drunella grandis from South Boulder Creek in Colorado in their barcodes based on the mitochondrial gene cytochrome c oxidase 1 (COI). It was most likely the same subspecies we have here, Drunella grandis grandis.
Buchwalter,DB; Cain,DJ; Martin,CA; Xie,L; Luoma,SN; Garland,JT 2008 Aquatic insect ecophysiological traits reveal phylogenetically based differences in dissolved cadmium susceptibility. Proceedings of the National Academy of Sciences 105 24, 8321-8326.
Buchwalter,DB; Luoma,SN 2005 Differences in dissolved cadmium and zinc uptake among stream insects: mechanistic explanations. Environmental Science and Technology 39, 498-504.
Clubb,RW; Gaufin,AR and Lords,JL 1974 Acute cadmium toxicity studies upon nine species of aquatic insects. Environmental Research 9(3) 332-341.
Abstract: Continuous-flow bioassays were employed to determine 96-hour median tolerance limits (TLm), for the stonefly, Pteronarcella badia (Hagen) (TLm was 18.0 mg Cd/l) and the mayfly, Ephemerella grandis grandis Eaton (TLm was 28.0 mg Cd/l). Ninety-six hours TLm values for other species of aquatic insects tested were not determined, since these species were relatively insensitive to cadmium.
Insects exposed for four days in cadmium-containing water, then placed in tap water, show a linear rate of cadmium loss. This loss may lower or prevent mortality under ideal conditions.
Colburn,T 1982a Aquatic insects as measures of trace element presence in water: Cadmium and Molybdenum. Aquatic Toxicology and Hazard Assessment: Fith Conference, ASTM STP 766, J.G. Pearson, R.B. Foster, and W.E. Bishop, Eds., American Society for Testing and Materials, pgs 316-325.
The author studied macroinvertebrates in Coal Creek and the Slate River near Crested Butte in 1979. She found that Drunella grandis bioaccumulated cadmium and molybdenum the most of the aquatic insects she studied. Both live and dead insects sorbed cadmium, indicating "that cadmium uptake is more than a physiological process."
Colburn,T 1982b Measurement of low levels of molybdenum in the environment by using aquatic insects. 29, 422-428.
Dodds,GS 1923 Mayflies from Colorado: descriptions of certain species and notes on others. Transactions of American Entomological Society 69, 93-116. PDF
Eaton AE. 1884 A revisional monograph of recent Ephemeridae or mayflies. Transactions of the Linnean Society of London, Second Series, Zoology 3 Group II of the genera. pages 77-152.
The Reverend described this species as Ephemerella grandis on pages 128 and 129. Quote from page 326:"The natural length of the wings are shown by the hair lines." [While I copied the pdf file at 100% for this description and illustration, I don't know the scanning resolution, so I don't know if the wing lengths are accurate.] See Eaton's "Description of the Plates" for more information on his labels and methods.
Gaufin,AR; Clubb,R and Newell,R 1974 Studies on the tolerance of aquatic insects to low oxygen concentrations. Great Basin Naturalist 34:45-59. PDF
The authors studied the acute short term tolerance of aquatic insects to low oxygen. They used the 96 hour Median Tolerance Limit. They discussed Drunella grandis as Ephemerella grandis. The TLm96 for D. grandis was 3.0mg/l and 27% oxygen saturation.
Gaufin,AR and Hern,S 1971 Laboratory studies on tolerance of aquatic insects to heated waters. Journal of the Kansas Entomological Society 44:240-245. PDF
Abstract: "The mature larvae of fifteen species of aquatic insects (Diptera, Ephemeroptera, Plecoptera, and Trichoptera) and the scud (Amphipoda) were tested to determine their relative sensitivity to heated waters under laboratory conditions. The temperature at which 50% died after 96 hours (TLm96) was recorded as the lethal temperature. This ranged from 11.7 C for the torrential stream mayfly, Cinygmula par Baton, to 32.6 C for the snipefly, Atherix variegata Walker. " They discussed D. grandis as Ephemerella grandis. The TLm96 for Drunella grandis was 21.5°C.
Gilpin,BR and Brusven,MA 1970 Food habits and ecology of mayflies of the St. Maries River in Idaho. Melanderia 4:19-40. PDF
Discussed as Ephemerella (Drunella) grandis.
Hawkins,CP 1985 Food habits of species of ephemerellid mayflies (Ephemeroptera: Insecta) in streams of Oregon. American Midland Naturalist 113(2) 343-352. PDF
Kiffney,PM; Clements,WH 1994 Effects of heavy metals on a macroinvertebrate assemblage from a Rocky Mountain stream in experimental microcosms. Journal of the North American Benthological Society 13 4, 511-523.
Larkin,JM; HenkMC and Burton,SD 1990 Occurrence of a Thiothrix sp. attached to mayfly larvae and presence of parasitic bacteria in the Thiothrix sp. Applied and Environmental Microbiology 56:357-361. PDF
Abstract: " Larvae of the mayfly (Drunella grandis [Eaton]) from Diamond Fork Creek, Utah, were covered with a heavy growth of the sulfide-oxidizing bacterium Thiothrix. The bacterium did not seem to harm the mayfly, but the Thiothrix trichomes were parasitized by three morphologically distinct bacteria, two of which were cytoplasmic and one of which was probably periplasmic. At least two of the parasites destroyed the cytoplasmic contents of the Thiothrix sp., thus killing the host cell. Attempts to obtain the parasites in pure culture were unsuccessful. "
Lugo-Ortiz,CR and McCafferty,WP 1995 Annotated inventory of the mayflies (Ephemeroptera) of Arizona. Entomological News 106 3, 131-140.
Magnum,FA and Winget,RN 1993 Environmental profile of Drunella grandis Eaton (Ephemeroptera: Ephemerellidae) in the Western United States. Journal of Freshwater Ecology 8 2, 133-140.
Abstract: "In 898 stream stations in 11 western states, Drunella grandis Eaton exhibited broad physical habitat niche dimensions but moderate to narrow water quality niche dimensions. Nymphs were found over a wide range of channel gradients and substrate types, with tolerance to fine substrates as long as there were some rocky substrates. Occurrence was mostly random in relation to riparian vegetation. Nymphs were found in waters with a wide range of alkalinities, but frequency was low when alkalinity exceeded 250 mg/l. Drunella grandis commonly inhabited streams with conductivity over 400 µmhos/cm but was rarely found when it exceeded 800 µmhos/cm. Nymphs were found in higher than expected frequencies when sulfates were less than 50 mg/l, lower than expected when sulfates are 75-250 mg/l, and were not found in waters with sulfates over 250 mg/l. Distribution was near random over all states sampled with occurrence higher than expected at elevations between 6,000 and 8,000 feet."
McCafferty,WP; Durfee,RS; Kondratieff,BC 1993 Colorado mayflies (Ephemeroptera): an annotated inventory. Southwestern Naturalist 38 3, 252-274. PDF
Quote from page 265: "Drunella grandis was divided into three western subspecies by Allen and Edmunds (1962b), with D. grandis grandis typically found in Colorado, Arizona, New Mexico, Utah and Wyoming. The other subspecies are found further west or north, and no intergrades have as yet been reported from Colorado."
McCafferty,WP and Provonsha, AV The Mayflies of North AmericaSpecies List (Version 12Jan2009)
Here is the geographic range and synonyms:
Drunella grandis grandis (Eaton), 1884 [USA:FN,NW,SW]
* Drunella grandis (Eaton), 1884 (comb.)
* Ephemerella glacialis carsona Day, 1952 (syn.)
* Ephemerella grandis Eaton, 1884 (orig.)
* Ephemerella grandis grandis Eaton, 1884 (stat.)
* Ephemerella sp. No. 1 Mayo, 1952 (syn.)
McCafferty,WP and Wang,T-Q 2000 Phylogenetic systematics of the major lineages of Pannote mayflies (Ephemeroptera: Pannota). Transactions of American Entomological Society 126 1, 9-101.
Needham,JG 1927 The Rocky Mountain species of the mayfly genus Ephemerella. Annals of the Entomological Society of America 20:107-117.
Discussed as Ephemerella grandis.
Nehring,RB 1976 Aquatic insects as biological monitors of heavy metal pollution. Bulletin of Environmental Contamination and Toxicology 15 2, 147-154.
Poff,NL; Wellnitz,TA and Monroe,JB 2003 Redundancy among three herbivorous insects across an experimental current velocity gradient. Oecologia 134:262-269. PDF
Abstract: "We conducted streamside experiments to determine if the ability of herbivorous insects to remove algal periphyton varies with local current velocity. We used two mayfly species (Baetis bicaudatus and Drunella grandis) and one caddisfly species (Glossosoma verdona), which differ from one another in body morphology and mobility. Periphyton was grown for 30 days on ceramic tiles in constant velocity to create similar initial forage conditions for grazers. Tiles were transferred to three velocity regimes characteristic of the natural streambed: slow (3-5 cm s-1), medium (15-20 cm s-1) and fast (32-41 cm s-1). Four grazer treatments (Baetis, Drunella, and Glossosoma alone, and all species combined) were repeated for each velocity treatment to isolate the effect of local current on grazer ability to crop periphyton. Grazers differed in their abilities to remove periphyton across current treatments. Glossosoma removed significantly (P<0.05) more periphyton at fast versus either slow or medium velocities; Baetis showed a similar (but non-significant) trend; and, Drunella always removed about 75% of periphyton, irrespective of current. At fast current, periphyton removal was equivalent among the species. At medium current, Drunella removed significantly more than both Baetis and Glossosoma, whereas at slow current, Drunella removed more than Baetis, which removed more than Glossosoma. Periphyton removal under the combined three-grazer treatment was similar qualitatively to the combined effects of individual grazers. More periphyton tended to be removed as current increased, with the fast versus slow contrast showing marginal significance (P=0.10). Under all current regimes, the quantity of periphyton removed did not differ from the null model expectation of simple additive effects among individual grazers (i.e., no facilitation or inhibition). These experiments show that for some species, herbivory varies with current, which suggests that the herbivore "function" of cropping periphyton may vary with the environmental context of local current. Under some local velocities, however, different herbivore species "function" similarly and are potentially redundant with respect to periphytic removal. In naturally heterogeneous streams characterized by sharp gradients in local current velocity, we expect current-dependent species interactions to be common and at least partially contribute to intra-guild co-existence of species."
Rader RB; Ward JV. 1989 Influence of impoundments on mayfly diets, life histories, and production. Journal of the North American Benthological Society 8:64-73.
Robinson,CT and Minshall,GW 1986 Effects of disturbance frequency on stream benthic community structure in relation to canopy cover and season. Journal of the North American Benthological Society, 237-248. PDF
Abstract: " Field experiments were conducted to examine the effects of disturbance frequency on invertebrates and periphyton colonizing bricks in a third order Rocky Mountain (USA) stream. After an initial colonization period (30 days), sets of bricks were turned over at intervals of 0, 3, 9, 27, or 54 days. Invertebrate species richness and density were reduced as disturbance frequency increased. These trends were evident for both seasons (summer and fall) and sites (open vs. closed canopy). Invertebrate species diversity (H') displayed no effect during the fall experiment; however, H' was reduced at high frequencies of disturbance during the summer experiment. Baetis tricaudatus was the most abundant invertebrate on the substrata at both sites and seasons. Alloperla, Baetis, Cinygmula, Chironomidae, Drunella grandis, Hydropsyche, and Seratella tibialis increased in absolute abundances as disturbance frequency decreased. Four other abundant taxa (Capnia, Cleptelmis, Glossosoma, and Isoperla) displayed no clear response to disturbance in either absolute or relative abundances. Species in low abundance tended to colonize only the less frequently disturbed bricks. During both seasons, periphyton biomass increased as disturbance frequency decreased at the open canopy site, while no trend was apparent at the closed canopy site. Periphyton accumulation monitored over time and among treatments revealed that frequent disturbances maintained low standing crops at an open canopy site. These data suggest that disturbance frequency can directly influence the benthic community at the scale of individual rock "islands" by reducing invertebrate richness, total animal density, and periphyton biomass. The effect of disturbance on species diversity (H') was seasonal, further emphasizing the importance of considering seasonality in stream field studies. "
Short,RA; Canton,SP and Ward,JV 1980 Detrital processing and associated macroinvertebrates in a Colorado mountain stream. Ecology, 61(4), 727-732. PDF
Drunella grandis is referred to as Ephemerella grandis in this paper. Nymphs were found in all 4 of the plant species used to make leaf packs; alder, willow, aspen and pine.
Short,RA 1983 Food habits and dietary overlap among six stream collector species. Freshwater Invertebrate Biology 2:132-138. PDF
The United States Geological Survey (USGS) National Water Quality Assessment Data Warehouse (NAWQA) shows this species is present in Gunnison County. Data as of 1Sep2005
Ward,JV and Berner,L 1980 Abundance and altitudinal distribution of Ephemeroptera in a Rocky Mountain stream. In Advances in Ephemeroptera biology (pp. 169-177). Springer US. PDF
Discussed as Ephemerella grandis
Ward,JV, Kondratieff,BC and Zuellig,RE 2002 An Illustrated Guide to the Mountain Stream Insects of Colorado. 2nd ed. University Press of Colorado, Boulder, Colorado. 219 pages.
Has an illustration of the larvae Figure 41 on page 91, also reproduced on this website: http://waterknowledge.colostate.edu/drunella.htm
Ward,JV; Stanford,JA 1990 Ephemeroptera of the Gunnison River, Colorado, USA. In: Mayflies and Stoneflies. Ed: Campbell,IC Kluwer Academic Publishers, 215-220.
Wellnitz,T and Poff,NL 2012 Current-mediated periphytic structure modifies grazer interactions and algal removal. Aquatic Ecology, 46(4) 521-530. PDF
Abstract "By shaping the architecture and taxonomic composition of periphyton, stream current may create periphytic mats on which some grazers can feed and forage more effectively than others. Current-mediated periphytic structure also has the potential to foster positive interactions among grazers if one grazer's foraging facilitates another's access to algal food. To examine the extent to which these indirect effects of current influenced periphytic removal and grazer interactions, we conducted a mesocosm experiment with two common grazers, the caddisfly (Trichoptera) Glossosoma verdona and the mayfly (Ephemeroptera) Drunella grandis. Periphyton was allowed to colonize ungrazed tiles for 30 d and assume its natural growth form under three ranges of near-bed current, "slow" (1-5 cm s-1), "medium" (15-20 cm s-1), and "fast" (30-40 cm s-1). Tiles were then exposed to the two grazer species at five densities. A streambed survey quantified Glossosoma and Drunella distributions in relation to near-bed current and periphytic structure (i.e., diatom films vs. filamentous mats) in the Colorado River. After 22 days of grazing, periphytic removal by Glossosoma was influenced by near-bed current and attendant periphytic structure. In slow current, where senescent Ulothrix filaments were abundant, increased Glossosoma density was correlated with an increase in periphyton biomass. Larvae became entangled and immobilized by the diffuse and senescent Ulothrix mat that characterized slow velocity, and Glossosoma mortality and weight loss was greatest in this treatment. By contrast, Drunella reduced periphyton across all density and current treatments. Drunella density correlated with increased Glossosoma survivorship and weight gain in slow current. The driving mechanism for this facilitation appeared to be removal of entangling overstory filaments by Drunella. The streambed survey showed that Glossosoma were negatively associated with filamentous mats, lending support to the hypothesis that clearing action by Drunella in the slow current/senescent Ulothrix treatment facilitated Glossosoma growth and survival. Our study helps underscore the importance of evaluating species interactions over ranges of abiotic conditions and consumer pressure to understand the patterns and processes shaping benthic communities."
Winget,RN 1993 Habitat partitioning among three species of Ephemerelloidea. Journal of Freshwater Ecology 8 3, 227-234. PDF