Aquatic Insects of Michigan

by Ethan Bright, Museum of Zoology Insect Division and School of Natural Resources and Environment
University of Michigan

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Leptophlebiidae of Michigan - Identification

Adults (adapted from Edmunds and Waltz 1996)

    1a Hind wings with distinct costal projection 2
    1b Hind wings without such a costal projection 3
    2a(1a) Costal projection of hind wings in distal half of wing Habrophlebiodes americana (Banks)
    2b Costal projection of hind wing near midpoint of length of wing Choroterpes basalis (Banks)
    3a(1b) Penes of male with long, decurrent, median appendages, fused at base only Leptophlebia
    terminal (middle) filament often shorter and thinner than lateral cerci
    forewing with Cu1 and cu2 closer together than Cu1 and M in subbasal region where these veins are subparallel
    3b Penes of male variable, but not as above; Paraleptophlebia
    three subequal caudal filaments
    forewing with Cu1 and Cu2 separated in subbasal region by a space equal to that separating Cu1 and M

Mature Nymphs (adapted from Edmunds et al. 1975, Edmunds and Waltz 1996)

    1a Gills on Ab1 differently structured from those on succeeding segments, either forked or unforked linear lamellae, and those on Ab2-7 broadly bilamellate with 3-lobed apexes 2
    1b Gills on Ab1 similar in structure as those of the succeeding segments, sometimes smaller or more slender 3
    2a(1a) a. Gill on Ab1 single linear lamella Choroterpes basalis (Banks)
    b. Gills on Ab2-7 terminating in three filaments, the middle one longest and broadest
    2b a. Gill on Ab1 forked or bilamellate Leptophlebia
    b. Gills on Ab2-7 with slender median filament flanked by two blunt lobes
    3a(1b) a. Labrum with moderately deep V-shaped median emargination Habrophlebiodes americana (Banks)
    b. Abdominal terga with a small row of spinules present on the posterior margins of Ab6-10 only
    3b a. Labrum with an emargination only shallowly notched Paraleptophlebia
    b. Abdominal terga with a small row of spinules present on the posterior margins of Ab1-10

Leptophlebia
Adults
(adapted from Burian 2001)

    1a Males 2
    1b Females 4
    2a(1a) Outer 1/4-1/3 of forewings distinctly brown, or faintly stained brown (best seen in live, or freshly killed specimens; decays in alcohol) Leptophlebia nebulosa (Walker)
    2b Outer area of forewings not extensively pigmented, any coloration is restricted to stigmatic area 3
    3a(2b) Genitalia with large apical caps with long, straight outer margtins, and large distinct apical spines Leptophlebia cupida (Say)
    decurrent appendages of penes cross penis lobes at an angle approaching 90°
    appendages folded over entire length and curve centrally appearing not to reach base of notch between penis lobes
    pale median strip on abdominal terga usually broadly conencting to pale bandat posterior edge of terga, flanked by two well-defined cresecent-shaped spots, and two sublateral pale spots
    background color usually extensive, not restricted into broad w-shaped band
    3b Genitalia with shorter apical caps, with rounded outer margins and smaller apical spines Leptophlebia intermedia (Traver)
    decurrent appendages of penes cross penis lobes at about 45°
    appendages folded over entire length, but not curved ventrally so tips reach to or below base of notch between penis lobes
    abdominal terga with pale median stripe not usually forming a broad, distinct connection to pale band at posterior edge of terga, flanked by two variable crescent-shaped spots and two sublateral pale spots
    background coloration usually extensive, but sometimes localized into broad w-shaped band
    4a(1b) Abdominal terga with short pale median line not connected to pale band along posterior margins of terga Leptophlebia intermedia (Traver)
    median line flanked by large variable crescent-shaped spots or spots drawn out into thin streaks
    background color of terga usually extensive, or localized into broad w-shaped band
    4b Abdominal terga not as above, pale median line separated from pale posterior band on terga 1-3, but usually broadly connected to band on terga 4-7 5
    crescent-shaped spots flanking median line smaller and less variable, never drawn out into thin streaks
    background color never localized into broad w-shaped band
    Note: Couplet 5 requires dissection of abdomen and slide-mounted examination of eggs with compound microscope (see Burian 2001)
    5a(4b) Egg attachment structures composed of clusters of about six medium length pegs, surrounding two large pegs; peg clusters irregularly distributed over chorion Leptophlebia nebulosa (Walker)
    5b Egg attachment structures composed of pairs of large pegs irregularly distributed over chorion Leptophlebia cupida (Say)

Leptophlebia
Mature Nymphs
(adapted from Burian 2001)

    Note: accurate identification may require slide-mounting leg and mouth structures (see Burian 2001)
    1a a. Inner edge of forefemora with large palmate setae dominant Leptophlebia intermedia (Traver)
    b. All leg segments distinctly banded
    1b a. Inner edge of forefemora with a combination of medium and coarse uniserrate and biserrate setae, with no type dominant 2
    b. Legs unbanded or faint bands on tibiae and tarsi only, or distinct bands on tibiae and tarsi, but only faint bands on femora
    5a(4b) a. Peg-like seate on anterior 1/3-1/2 of dorsal surface of maxillary palpifer usually arranged in regular rows Leptophlebia nebulosa (Walker)
    b. Legs usually not banded or, at most, with faint bands on tibiae and tarsi only
    c. Setae on dorsum of labrum patterned (Fig. 84 in Burian 2001)
    5b a. Peg-like seate on anterior 1/3-1/2 of dorsal surface of maxillary palpifer usually not arranged in rows Leptophlebia cupida (Say)
    b. Legs usually with faint bands on all leg segments, or with distinct bands on tibiae and tarsi and faint bands on femora
    c. Setae on dorsum of labrum patterned (Fig. 80 in Burian 2001)

Paraleptophlebia
Adults
from Burks 1953)

    1a females cannot currently be keyed
    1b males 2
    2a(1b) In lateral view, forceps of genitalia with a large, dorsal enlargement near base Paraleptophlebia debilis (Walker)
    also: All longitudinal veins of forewing tan, with C, Sc, and R slightly darker; tergites on Ab2-7 with a pair of posterolateral, dark brown spots and a dark brown crossband at posterior margin
    2b In lateral view, forceps without a large, dorsal enlargment near base 3
    3a(2b) Lobes of penes long, straight, and slender Paraleptophlebia praepedita (Eaton)
    also: Each lobe of penes with a terminal papilla
    3b Lobes of penes relatively short and broad 4
    4a Terga of Ab2-6 almost entirely dark brown 5
    4b Terga of Ab2-6 almost or completely white 6
    5a(4a) Lobes of penes without decurrent appendages, each lobe with a beaklike, lateral projection Paraleptophlebia adoptiva (McDunnough)
    5b Lobes of penes each with a large, decurrent appendage Paraleptophlebia ontario (McDunnough)
    6a(4b) Lobes of penes without decurrent appendages Paraleptophlebia mollis (Eaton)
    6b Lobes of penes with decurrent appendages 7
    7a(6b) a. Lobes of penes without apicolateral projections Paraleptophlebia volitans (McDunnough)
    b. Decurrent appendages slender, bifid at apex
    7b a. Lobes of penes with apicolateral projections 8
    b. Decurrent appendages not bifid at apex
    8a(7b) a. Tergites of Ab2-7 white, with spiracular dots Paraleptophlebia guttata (McDunnough)
    b. Mesal apical angles of penis lobes divergent
    8b a. Tergites of Ab2-7 white, with apiracular dots and a large, brown spot near each posterolateral angle Paraleptophlebia strigula (McDunnough)
    b. Mesal apical angles of penis lobes convergent

References

    Burian SK. 2001. Revision of the genus Leptophlebia Westwood in North America (Ephemeroptera: Leptophlebiidae: Leptophlebiinae). Ohio Biological Survey Bulletin New Series 13(3). vi + 80 pp.
    Edmunds GF, Waltz RD. 1996. Ephemeroptera, pp. 126-163 in Merritt RW, Cummins KW (editors), An Introduction to the Aquatic Insects of North America, 3rd Edition. Kendall/Hunt Publishing Company: Dubuque, Iowa.
    Edmunds GF, Jensen SL, Berner L. 1976. The mayflies of North and Central America. University of Minnesota Press: Minneapolis, Minnesota. x + 330 p.

Page created: June 13, 2003; Last edited: November 06, 2013 (EB)