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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Lestidae (Stream and Pond Spreadwings) of Michigan - Identification

Lestidae is a widely distributed family of large-sized, slender damselflies with narrow wings. There are two genera of Lestidae in North America - Archilestes Selys and Lestes Leach. Archilestes is principally a neotropical genus, with two species found north of Mexico. Lestes is cosmopolitian. Presently 9 species of Lestes have been recorded in Michigan and are all fairly widespread across the state. Given the rapid range expansion of Archilestes grandis (Gloyd 1980) from Southwestern into the Midwest (including Illinois, Indiana and Ohio) and Northeastern USA, and the numerous records of this species in the states and province surrounding southern Michigan, it is surprising that specimens were only recently collected (2005).

Adults are medium and large-sized damselflies that, in North America at least, on rest hold their narrow, petiolate wings open and position their long narrow bodies inclined downward (Paulson 2011, Westfall and May 2006). Nymphs are characterized by their distinctively long, narrowed labium that extends in repose back to the metacoxae. Based on current knowledge, male nymphs of Lestes cannot always be identified to species.

Nymphs are usually daytime surface predators (Fischer 1972, Eriksen 1984), and are well adapted for visual hunting: they possess more ommatidia eye cells than any other family of Odonata except Aeshnidae (Corbet 1962). They are found in aquatic bodies with ample aquatic vegetation and/or organic matter, usually ponds, bogs, and marshes, but also in slow-moving streams, rivers and their impoundments (for species' habitat accounts, see Walker 1941; but see also Westfall and Tennessen 1973). Several species are able to quickly develop in temporary pool and ponds. Eriksen (1984) studied the ability of L. disjunctus in a Montana bog pond control their shunt their energy toward day-time feeding when oxgyen levels are highest, and become inactive at night to reduce metabolic demands, metabolism. During nightime, when oxygen levels and larval respiration is low, nymphs are largely inactive, thus in effect conserving energy for daylight hours when oxygen levels are highest, and supportive of active predation. The author believes this allows nymphs to most effectively support rapid growth and emerge before aquatic conditions (temperature, oxygen) become too difficult for nymphs to survive. Nymphs of Archilestes are found in ponds, empoundments and streams of slow or moderate flow (Westfall and May 1996), and it's ability to survive in poor water quality may be a reason for this species rapid expansion throughout central and eastern North America (see Moskowitz and Bell, 1998). Its range expansion may also be a result of human movement of aquatic plants for restoration projects, plants that may have harbored A. grandis eggs that subsequently hatched.

Taxonomic references: Westfall and May 2006, Paulson 2011, Walker 1953

Adults

1a a. Proximal side of quadrangle of forewing equal to, or slightly less than, 1/2 the length of the posterior side Archilestes grandis (Rambur)
b. Pterostigma longer than 3.0 mm
c. Vein M2 usually arising about one cell beyond the nodus
1b a. Proximal side of quadrangle of forewing equal to, or less than, 1/3 the length of the posterior side Lestes, 2
b. Pterostigma longer than 2.8 mm
c. Vein M2 usually arising more than 2 cells beyond the nodus
 
2a(1b) Males
3
2b Females 11
 
3a(2a) Paraprocts not more than 1/2 as long as the cerci 4
3b Paraprocts distinctly greater than 1/2 the length of the cerci 5
 
4a(3a) a. Wings flavescent Lestes eurinus Say
b. Cerci with a serrated prominence near the middle of the inner margin
4b a. Wings hyaline, or only slightly tinted in older specimens Lestes congener Hagen
b. Cerci without a serrated prominence near the middle of the inner margin
 
5a(3b) Paraprocts longer than the cerci Lestes inaequalis Walsh
5b Paraprocts shorter than the cerci, at most reaching their tips 6
 
6a(5b) Paraprocts sigmoid in shape, and slender, with apexes divergent Lestes unguiculatus Hagen
also: Cerci with basal tooth very narrow and acute, and with the sital tooth very small, often indistinct, located approximately 2/3 the distance from the base to the apex of the appendage, and separated from the basal tooth by a medially concave, strongly serrated ridge; rear of head black; mesepisterna each with the black or brown stripe contiguous with the middorsal carina
6b Paraprocts not sigmoid, apexes not divergent 7
 
7a(6b) Paraprocts broadened, in dorsal view appearing somewhat boot-shaped Lestes dryas Kirby
also: Dorsum of thorax metallic green
7b Paraprocts not expanded at the tips, the sides parallel and, in dorsal view, not noticeably boot-shaped 8
 
8a(7b) Cercus with a distinct basal tooth only, usually followed by a more or less serrated margin Lestes vigilax Hagen
also: Dorsum of thorax usually with a wide metallic green stripe, sometimes black, contiguous with the middorsal carinaalso: Rear of head black; paraprocts at least 3/4x as long as the cerci; abdominal length at least 37 mm; two partial rows of cells distal to the pterostigma between the costa and R1
8b Cercus with a distinct distal tooth somewhat resembling a basal tooth in shape 9
 
9a(8a) a. Hindwing < 2/3 the length of the abdomen Lestes rectangularis Say
b. Paraprocts curving sharply downward in apical third
9b a. Hindwing approximately 2/3 the length of the abdomen 10
b. Paraprocts not curving downward (unless due to postmortem distortion)
also:Tips of paraprocts extending beyond the distal tooth of the cerci; Ab2 about 1/2 as long as Ab3; Labrum pale bluish
 
10a(9b) a. Ab2 about 1/2 as long as Ab3
Lestes disjunctus Selys
b. Swelling at the base of basal tooth of the cerci relatively distant from the tooth, and forming terminus of low ridge extending laterally and posteriorly to beyond level of the apex of the tooth
c. White, shield-shaped membranous area on the vesicle of the penis widest at, or posterior to, its midlength
d. Distal tooth of the cerci variable, often about as large as the basal tooth
10a(9b) a. Ab2 usually about 3/5 as long as Ab3 Lestes forcipatus Rambur
b. Swelling at the base of basal tooth of the cerci relatively close to the tooth, and not forming a part of the such a ridge
c. White, shield-shaped membranous area on the vesicle of the penis widest at, or very close to, the front margin
d. Distal tooth of the cerci always distinctly smaller than the basal tooth
 
11a(1b) Ovipositor distinctly longer than Ab7, the tips of the valves reaching as far back as the extreme ends of the paraprocts 12
11b Ovipositor usually shorther than Ab7 (except nearly equal in most unguiculatus), the valves not extending to the ends of the paraprocts 13
 
12a(11a) a. Dorsum of thorax almost entirely metallic green
Lestes dryas Kirby
b. Thorax usually without a dark spot above the metapleural carina
c. Rear of head black
12a(11a) a. Dorsum of thorax mostly brown or black, never green Lestes forcipatus Rambur
b. A dark thoracic spot usually present above the metapleural carina, although it may be small
c. Rear of head usually black below and pale above
 
13a(11b) a. Wings flavescent
Lestes eurinus Say
b. Posterolateral margins of basal plate of the ovipositor rounded
also: Dark mark above the matepleural carina large and elongate, often confluent with the dark stripe on the metapleural suture; pterostigma surmounting 3-4 cells; large species
13b a. Wings hyaline or at most slightly tinged brownish 14
b. Posterolateral margins of basal plate of the ovipositor angulate, the angle generally produced into an acute process
 
14a(13b) Ab7 distinctly less than 2x as long as the ovipositor
15
14b Ab7 about or more than 2x as long as the ovipositor 17
 
15a(14a) a. Dorsum of thorax and abdomen dark brown, with a dull metallic luster
Lestes congener Hagen
b. Humeral stripe pale yellowish, linear
c. Dark spot present above and below the metapleural carina
15b a. Dorsum of thorax and abdomen paler bronze-brown 16
b. Pale, dull yellow humeral stripe 1/3-1/2 as broad as the dark area on each side of the median carina
c. Dark spot absent above and below the metapleural carina
 
16a(15b) a. Ab7 at least 1.5x as long as the ovipositor, excluding the styli
Lestes disjunctus Selys
b. Dark areas of abdomen bronze to black
also: Rear of head black except around the neck
16a(15b) a. Ab7 less than 1.5x as long as the ovipositor, excluding the styli Lestes unguiculatus Hagen
b. Dark areas of abdomen usually greenish
also: Rear of head with pale areas distinct above, and usually reaching the compound eye
 
17a(14b) a. Dorsum of thorax dark brown, scarcely metallic
Lestes rectangularis Say
b. Median carina and humeral stripes grey, the latter more than half as wide as the dark mesepisternal area
c. Extensor surfaces of tibiae pale yellow
also: Outer surfaces of meso- and metatibiae, and the basal half of the corresponding tarsi always pale; wing tips with few doubled cells in marginal row, none between the distal end of the pterostigma and the end of vein R1; lateral stripe of mesepisternum blue-grey to yellow; postnodal crossveins usually no more than 12
17b a. Dorsum of thorax metallic green 18
b. Median carina and humeral stripes reddish or yellowish
c. Extensor surfaces of tibiae yellow or dark brown
 
18a(17b) a. Reddish brown humeral stripe 1/3 or more wide as the metallic area on each side of the median carina
Lestes vigilax Hagen
b. Tibiae dark brown
18b a. Yellowish humeral strip less than 1/4 as wide as the metallic area on each side of the median carina Lestes inaequalis Walsh
b. Extensor surfaces of tibiae yellow
also: Ovipositor with the vental margin nearly straight or convex; basal plate of the ovipositor with the posterolateral margin obtusely angulate
 

Mature Nymphs

1a a. a. Distal margin of palpal lobe with three sharp processes, the outermost markedly shorter than the movable hook Archilestes grandis (Rambur)

b. Caudal gills with two well-defined dark crossbands

Archilestes grandis lateral gill 12x
1b a. Distal margin of palpal lobe with four processes, three sharp hooks and one truncate lobe whose edge has a serrated border within upper notch 2
b. Caudal gills never with two distinct and complete dark crossbands
 
2a(1b) a. a. Lateral spines present on Ab1, 2, 3 or 4-9 3
b. All gills of equal width along entire length, only 1/6 as wide as long (except at extreme tip)
2b a. Lateral spines present on Ab5 or 6-9 4
b. Gills gradually tapering distally, widest part of median gill 1/3 to 1/5 length of gill, with dorsal margin convex
 
3a(2a) a. Lateral spines present on Ab1-9 Lestes inaequalis Walsh
b. Black-brown band on apexes of third tarsal segments
c. Slow streams and lagoons
3b a. Lateral spines absent on Ab1, present on Ab2 or 3-9 Lestes vigilax Hagen
b. Apices of third tarsal segments without black-brown banding
c. Bog-margined lakes
 
4a(3a) a. Lateral spines present on Ab4-9 Lestes eurinus Say
b. Mature nymphs with hind (outer) wing pad ca. 0.75x the length of the lateral gills
c. Serrated process of palpal lobe with denticles jagged and irregular
d. Total length (including lateral gills) of mature nymphs >35 mm
a. Bog ponds, local distribution
4b a. Lateral spines present on Ab5 or 6-9 (very rarely segment 4 on L. disjunctus and L. unguiculatus) 5
b. Hind wing pad at most slightly more than 0.5x length of lateral gill
c. Serrated process of palpal lob with denticles usually more or less uniform and regularly spaced
d. Total length (including lateral gills) of mature nymphs < 34 mm
e. Variable habitats
 
5a(4b) a. Movable hook of each palpus with three or four long setae 6
5b a. Movable hook of each palpus with two long setae 8
 
6a(5a) a. Width of slenderest part of prementum ca. 1/3 the width of the expanded distal part at base of palpi Lestes congener Hagen
b. Length of prementum < 3.5 mm in mature nymphs
also: Permenent and semi-permanent waters
6b a. Width of slenderest part of prementum < ca. 1/4x width of the expanded distal part at base of palpi 7
b. Length of prementum > 3.5 mm in mature nymphs
 
7a(6b) a. Ovipositor of female extending little if any beyond apex of Ab10 Lestes unguiculatus Hagen
b. Labium extending rearward to middle of metacoxae, at most
c. Total length, including caudal gills, usually < 30 mm
d. Perminent or semi-perminent still marshy waters, often abundant
7b a. Ovipositor of female extending well beyond apex of Ab10 Lestes dryas Kirby
b. Labium extending rearward beyond metacoxae
c. If labium not extending so long, then total length usually >30mm
d. Common in temporary or semi-perminent ponds, less common in perminent marshy waters
 
8a(5b) a. Slender proximal part of prementum at most 2x the length of the expanded distal part 9
8b a. Slender proximal part of prementum distinctly >2x (usually 2.5x or greater) the length of the expanded distal part 10, (females only)
 
9a(8a) a. Venter of Ab3-9 with a median row of paired, brown, elongate spots at posterior margins Lestes rectangularis Say
b. Movable hook of palpal lobe about 4x as long as its middle width
c. Ovipositor of female extending only to apex of Ab10
9b a. Venter of abdominal without such paired spots Lestes unguiculatus Hagen
b. Movable hook of palpal lobe about 3x as long as its middle width
c. Ovipositor of female extending slightly beyond Ab10
 
10a(8b) a. Ovipositor of female extending to level of tips of cerci or beyond Lestes forcipatus Rambur
10b a. Ovipositor of female extending only to level of bases of cerci Lestes disjunctus Selys, Lestes rectangularis Say
 
 

References

Corbet PS. 1962. A biology of dragonflies. H. F. & G. Witherby Ltd.: London. xvi + 247 pp.
Eriksen CH. 1984. The physiological ecology of larval Lestes disjunctus Selys (Zygoptera: Odonata). Freshwater Invertebrate Biology 3(3):105-117.
Fischer Z. 1972. The energy budget of Lestes dryas Kirby (Odonata). Pol. Arch. Hydrobiol. 19:215-222.
Gloyd LK. 1980. The taxonomic status of the genera Superlestes and Cyptolestes Williamson 1921 (Odonata: Lestidae). Occasional Papers of the Museum of Zoology, University of Michigan 694:1-3.
Moskowitz DP, Bell DM. 1998. Archilestes grandis (great spreadwing) in central New Jersey, with notes on water quality. Bulletin of American Odonatology 5(3):49-54.
Paulson D. 2011. Dragonflies and damselflies of the East. Princeton Field Guides. Princeton University Press, Pinceton, New Jersey, USA. 538 p.
Walker EM. 1953. The Odonata of Canada and Alaska, Vol. 1. University of Toronto Press: Toronto, Ontario. 292 pp.
Walker EM. 1941. List of the Odonata of Ontario with distributional and seasonal data. Transactions of the Royal Canadian Institute 32(2):201-265.
Walker EM. 1953. The Odonata of Canada and Alaska, Vol. 1. University of Toronto Press: Toronto, Ontario. 292 pp.
Westfall MJ, May ML. 2006. Damselflies of North America, Revised Edition. Scientific Publishers, Gainesville, Florida, USA. xii + 502 pp.
Westfall MJ, Tennessen KJ. 1973. Description of the nymph of Lestes inaequalis (Odonata: Lestidae). The Florida Entomologist 56(4):291-293.

Page created: July 17, 1998 - Last updated: February 21, 2017 (EB)