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Ephemeroptera: Baetidae of Gunnison County, Colorado

Fallceon quilleri - Small Minnow Mayfly

(Dodds 1923)
Updated 12 May 2021
TSN 568601


F. quilleri is a small mayfly with a wide range across the USA, Canada and Mexico. It is rare in the upper Gunnison Basin. This species has a life cycle as short as 8-11 days in temporary desert and plains streams (Fritz and Dodds 2004).

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Dodds,GS 1923 Mayflies from Colorado: descriptions of certain species and notes on others. Transactions of American Entomological Society 69, 93-116. PDF
     Described from South Boulder Creek on the Front Range of Colorado as Baetis quilleri.

Fritz,KM and Dodds,WK 2004 Resistance and resilience of macroinvertebrate assemblages to drying and flood in a tallgrass prairie stream system. Hydrobiologia, 527(1) 99-112. PDF
     The found F. quilleri has a life cycle as short as 18 days when threatened by drying stream conditions.

Gray,LJ 1981 Species composition and life histories of aquatic insects in a lowland Sonoran desert stream. American Midland Naturalist 106 (2) 229-242.
     Discussed as Baetis quilleri. Quote from page 231: "Baetis quilleri eggs, obtained from reared adults, hatched in 1 or 2 days. Subimagos emerged in 9-11 days. Larvae with fully developed wing pads were present after 6 days at 17-25 °C in trays."

Gill,BA; Harrington,RA; Kondratieff,BC; Zamudio,KR; Poff,NL and Funk,WC 2014 Morphological taxonomy, DNA barcoding, and species diversity in southern Rocky Mountain headwater streams. Freshwater Science 33(1) 288-301. PDF
     Working in wadeable streams on the Front Range of Colorado, they found this species and two cryptic Fallceon species.

Lugo-Ortiz,CR; McCafferty,WP 1998 A new North American genus of Baetidae (Ephemeroptera) and key to Baetis complex genera. Entomological News 109(5) 345-353.
     Page 351, Figure 14 is an illustration of the left mandible of F. quilleri, showing the setal tuft.

Lugo-Ortiz,CR; McCafferty,WP and Waltz,RD 1994 Contribution to the taxonomy of the Panamerican genus Fallceon (Ephemeroptera:Baetidae) Journal of the New York Entomological Society. 102:460-475. PDF
     Abstract: "The baetid mayfly genus Fallceon is currently known from Central America, the Greater Antilles, Mexico, and the United States, and includes eleven nominal species: F. alcarrazae, new combination, F. eatoni, F. fortipalpus, new species, F. garcianus, F. longifolius, new combination, F. nikitai, F. planifrons, new combination, F. poeyi, F. quilleri, F. sextus, new combination, and F. testudineus, new combination. Larvae belonging to the genus include species with consistent mouthpart morphology but variable with respect to development of a cephalic frontal keel and subapical tarsal claw setae. Caribaetis, originally considered a Cuban subgenus of Baetis, is shown to be a synonym of Fallceon. Baetis sonora is shown to be a synonym of Fallceon quilleri. Fallceon fortipalpus is described from the egg and larval stages. Larvae of F. longifolius, F. planifrons, and F. quilleri are redescribed, and the egg of F. quilleri is described for the first time. Fallceon longifolius is reported from continental North America (Mexico) for the first time. A key to the known larvae of Fallceon is provided."

McCafferty,WP and Provonsha, AV The Mayflies of North America Species List (Version 8Feb2011)
     Here are the geographic range and synonyms for F. quilleri:
Fallceon quilleri (Dodds), 1923 [CAN:NE,NW;MEX:FS,SW;USA:NE,NW,SE,SW]
    * Baetis buenoi Allen, 1985 (syn.)
    * Baetis byblis Allen & Murvosh, 1983 (syn.)
    * Baetis cleptis Burks, 1953 (syn.)
    * Baetis endymion Traver, 1935 (syn.)
    * Baetis erebus Traver, 1935 (syn.)
    * Baetis leechi Day, 1954 (syn.)
    * Baetis quilleri Dodds, 1923 (orig.)
    * Fallceon buenoi (Allen), 1985 (syn.)
    * Fallceon byblis (Allen & Murvosh), 1983 (syn.)

McMullen,LE; De Leenheer,P; Tonkin,JD and Lytle,DA 2017 High mortality and enhanced recovery: modelling the countervailing effects of disturbance on population dynamics. Ecology Letters, 20(12), pp.1566-1575. PDF

Waltz,RD and McCafferty,WP 1987 New genera of Baetidae for some Nearctic species previously included in Baetis Leach (Ephemeroptera). Annals of the Entomological Society of America, 80(5) 667-670. PDF
     Abstract: "Certain Nearctic species originally described in the genus Baetis Leach lack the apomorphy possessed by other species described in Baetis and several related genera. This apomorphy is a patch of setae ventral on the femora of larvae. As a result, Baetis is here restricted to a more monophyletic concept, to include species with a patch of setae ventrally on the femora; and the nonconforming species that lack this character are placed in three new genera as follows: Fallceon, n. gen., type species Baetis quilleri Dodds as Fallceon quilleri (Dodds), n. comb., also includes Fallceon buenoi (Allen), n. comb., Fallceon byblis (Allen & Murvosh), n. comb., and Fallceon eatoni (Kimmins), n. comb.; Acerpenna, n. gen., type species Baetis macdunnoughi Ide as Acerpenna macdunnoughi (Ide), n. comb., also includes Acerpenna pygmaea (McDunnough), n. comb.; Diphetor, n. gen., type species Baetis hageni Eaton as Diphetor hageni (Eaton), n. comb., also includes Diphetor devinctus (Traver), n. comb."

Zickovich,JM and Bohonak,AJ 2007 Dispersal ability and genetic structure in aquatic invertebrates: a comparative study in southern California streams and reservoirs. Freshwater Biology, 52(10) 1982-1996. PDF
     Abstract: "1. The natural seasonal drying and flooding of southern California streams have been altered over the past century by activities related to agriculture, flood control, and reservoir construction. The genetic structure and diversity of aquatic invertebrates inhabiting these environments is largely unexplored, and may be important for conservation.
2. We sampled two species of aquatic invertebrates with different dispersal abilities to assess genetic structure and diversity, and make inferences about the evolutionary processes that underlie these genetic patterns. The mayfly Fallceon quilleri, which has a winged terrestrial stage, was sampled from perennial and intermittent streams from three catchments across San Diego County. The amphipod Hyalella azteca was sampled from streams (perennial and intermittent) and reservoirs in a single catchment (San Dieguito). Because it is obligately aquatic throughout its life-cycle, H. azteca was assumed to disperse less than F. quilleri.
3. Intrapopulation and overall genetic diversity was higher in F. quilleri than in H. azteca. In F. quilleri there was very little genetic divergence among populations, and most of the genetic differentiation that was observed could be attributed to a single population. In H. azteca, populations were markedly differentiated between the upper and lower segments of the San Dieguito basin, which are separated by a c. 10 km section of stream that rarely has surface flow. Within both segments, genetic divergence between sites connected by reservoirs and perennial streams was not significantly different.
4. Our results suggest that F. quilleri disperses widely and thus avoids genetic bottlenecks and marked levels of population differentiation that may be expected from frequent extinctions and recolonizations. In contrast, restricted dispersal in H. azteca is associated with relatively low genetic diversity and high genetic divergence across a portion of the catchment in which surface flow is rare."

Brown,WS 2007 Ephemeroptera of Gunnison County, Colorado