Aquatic Insects of Michigan
by Ethan Bright, Museum of Zoology Insect Division and School of Natural Resources and Environment
University of Michigan
- Home
- Species Lists
- Coleoptera
- Diptera
- Ephemeroptera
- Acanthametropodidae
- Ameletidae
- Ametropodidae
- Arthropleidae
- Baetidae
- Baetiscidae
- Behningiidae
- Caenidae
- Ephemerellidae
- Ephemeridae
- Heptageniidae
- Isonychiidae
- Leptohyphidae
- Leptophlebiidae
- Metretopodidae
- Neoephemeridae
- Oligoneuriidae
- Palingeniidae
- Polymitarcyidae
- Potamanthidae
- Pseudironidae
- Siphlonuridae
- Heteroptera
- Hymenoptera
- Lepidoptera
- Megaloptera
- Neuroptera (Sisyridae)
- Odonata
- Orthoptera
- Plecoptera
- Trichoptera
- Other Orders
- Keys/Identification
- Aquatic Insects of Michigan
Simulium Enderlein
The keys below are adapted from from Adler et al. 2004. Determination of a number of species requires interpretation of banding patterns and structure of polytene chromosomes, details of which and procedures of preparattion are contained in that work or supporting references.
AdultsPupae
1a a. Females 2 1b a. Males 27 2a(1a) a. Wing with basal section of radius bearing hair dorsally 3 2b a. Wing with basal section of radius without hair, or with few hairs, dorsally 19 3a(2a) a. Claws toothless also: lacina (slide mounted) with retorse teeth; mandible (slide mounted) with serrations; spermatheca with pigmentation typically extended onto spermathecal duct Simulium furculatum (Shewell) 3b a. Claws each with basal thumblike lobe 4 4a(3b) a. Tibia with integument and hair yellow on basal 2/3, contrasting with brown pigment on apical 1/3 Simulium bracteatum Coquillett, Simulium exulatum Adler, Currie & Wood, Simulium pilosum (Knowlton & Rowe), Simulium violator Adler, Currie & Wood b. Postscutellum with patches of hair posteriorly (sometimes rubbed off) c. Spermatheca pigmented at junction with spermathecal duct 4b a. Tibia with integument typically uniformly brown (paler in teneral specimens) and hair silvery or pale golden 5 b. Postscutellum without patches of hair c. Spermatheca lacking pigment at junction of spermathecal duct 5a(4b) a. Precoxal bridge incomplete 6 b. Genital fork with each arm expanded into triangular lateral plate, typically with its posterior margin perpendicular to longitudinal body axis c. Each lateral plate with or without prominent anteriorly directed apodeme 5b a. Precoxal bridge complete 7 b. Genital fork with each arm variously expanded, but not as triangular lateral plate c. Each lateral plate without prominent anteriorly directed apodeme 6a(5a) a. Genital fork with each lateral plate bearing weakly developed, anteriorly directed apodeme Simulium johannseni Hart 6b a. Genital fork with each lateral plate bearing prominent, anteriorly directed apodeme Simulium annulus (Lundström), Simulium emarginatum Davies, Peterson & Wood also: Anal lobe in ventral view incised medially, in lateral view with anterior margin unsclerotized 7a(5b) a. Basitarsus of hind leg with pedisulcus typically long and shallow, its depth < 0.33 x the width of segment
8 b. Antenna with pedicel larger than basal flagellomere 7b a. Basitarsus of hind leg with pedisulcus typically short and deep, its depth at least 0.33-0.50 x the width of segment 11 b. Antenna with pedicel smaller than basal flagellomere 8a(7a) a. Forecoxa with integument yellowish, contrasting with color of adjacent thorax Simulium congareenarum (Dyar & Shannon) also: Claws (slide mounted) each about < 1/2 length of last tarsomere; spermatheca about 0.75 x as long as stem of genital fork 8b a. Forecoxa with integument gray or brown, not contrasting with color of adjacent thorax 9 9a(8b) a. Frons at narrowest part 1/9-1/12 width of head Simulium innocens (Shewell) 9b a. Frons at narrowest part 1/5-1/8 width of head 10 also: Palpomere 3 (slide mounted) in lateral view slender or rather bulbous, with sensory vesicle occupying about < 0.25 its area; anal lobe with about half of medial area unsclerotized 10a(9b) a. Genital fork with lateral plate of each arm bearing dark sclerotized line along the posterior margin Simulium excisum Davies, Peterson & Wood 10b a. Genital fork with lateral plate of each arm weakly sclerotized line along the posterior marginalso: Legs uniformly dark brown (nonteneral specimens) Simulium anatinum Wood 11a(7b) a. Katepisternum with patch of hair on dorsal margin (in rubbed specimens, sockets visible after cleaning)
12 11b a. Katepisternum bare 13 12a(11a) a. Scutum with silvery hair Simulium croxtoni Nicholson & Mickel b. Katepisternum with patch of hair typically central, small (<20 hairs) 12b a. Scutum with golden hair Simulium gouldingi Adler, Currie & Wood b. Katepisternum with patch of hair typically extended across the dorsal margin 13a(11b) a. Scutum with hair pale brassy Simulium quebecense Twinn b. Anal lobe in lateral and ventral views with half or more unsclerotized 13b a. Scutum with hair golden, pale golden, or silvery 14 b. Anal lobe in ventral view with less than half unsclerotized 14a(13b) a. Scutum with hair predominantly silvery Simulium burgeri Adler, Currie & Wood also: Anal lobe in ventral view with anteromedial 1/3 unsclerotized, in lateral view with a small ventral spot unclerotized 14b a. Scutum with hair predominantly pale golden to golden 15 15a(14b) a. Anal lobe in lateral and ventral views almost bisected transversely by an unsclerotized area 16 15b a. Anal lobe in lateral and ventral views unsclerotized in anterior half or less 17 16a(15a) a. Genital fork with the lateral plate of each arm expanded into a large, posteromedially directed thumblike lobe Simulium craigi Adler & Currie b. Anal lobe in lateral view with the anterior margin weakly sclerotized 16b a. Genital fork with the lateral plate of each arm truncated posteromedially Simulium fionae Adler b. If anal lobe expanded into a thumblike lobe, then anal lobe in lateral view well sclerotized 17a(15b) a. Stem vein with golden hair Simulium aestivum Davies, Peterson & Wood 17b a. Stem vein typically with shiny brown hair 18 18a(17b) a. Genital fork with space enclosed by arms as long as wide or longer, often subcircular Simulium modicum Adler, Currie & Wood b. Abdomen often pale gray or brownish orange 18b a. Genital fork with space enclosed by arms wider than long, often subrectangular or suboval Simulium silvestre (Rubtsov) b. Abdomen typically gray 19a(2b) a. Claws each with basal thumblike lobe 20 19b a. Claws either toothless or each with small subbasal tooth 22 20a(19a) a. Scutum with 3 dark gray or brown longitudinal stripes (especially prominent in rubbed specimens) Simulium meridionale Riley 20b a. Scutum unicolorous, without stripes, or with at most 3 faint, pale longitudinal stripes visible in rubbed specimens 21 21a(20b) a. Frons gray, pollinose Simulium johannseni Hart b. Scutum not shiny 21b a. Frons bluish gray to brownish, shiny Simulium rugglesi Nicholson & Mickel b. Scutum subshiny, with thin gray pollinosity also: Wing with subcosta bare on ventral surface; basal 2 antennal segments distinctly paler than remainder 22a(19b) a. Claws small, smoothly curved, (slide mounted if necessary) each with a small subbasal tooth Simulium murmanum Enderlein also: Anal lobe in ventral view large, ovoid to nearly circular, well sclerotized; hypogynial valve short, its outer margin smoothly divergent from Ab8 sternite, and rounded posteriorly; shiny species, without reddish orange tinges on scutum; frons typically shiny, contrasting with pollinose clypeus; genital fork with lateral plate of each arm bearing a strongly sclerotized, ventrally directed tubercle 22b a. Claws (slide mounted if necessary) toothless 23 23a(22b) a. Scutum in anterolateral view with distinct longitudinal stripe(s) 24 23b a. Scutum in anterolateral view without longitudinal stripe(s), although prinose spots can be present anteriorly and extended slightly posteriorly 25 24(23a) a. Fore tibia anteriorly without white patch Simulium pictipes Hagen b. Abdomen with a single row of black patches dorsally c. Subcosta typically with row of hairs on ventral surface d. Ab7 sternum with a fringe of long hair also: Anal lobe in lateral view with posteroventral margin extended as an acute point 24b a. Fore tibia anteriorly with white patch Simulium tribulatum Lugger, Simulium vittatum Zetterstedt b. Abdomen with black patches both dorsally and laterally c. Subcosta typically bare on ventral surface, or with at most 3 hairs d. Ab7 sternum without fringe of long hair also: Anal lobe in lateral view with outer margin mostly unpigmented, weakly sclerotized 25a(23b) a. Subcosta bare on ventral surface, or with at most 4 hairs 26 b. Hypogynial valves with inner margins divergent, each valve divided obliquely into anterior, weakly sclerotized setose region, and posterior, well-sclerotized bare region 25b a. Subcosta with rows of hair on ventral surface 27 b. Hypogynial valves with inner margins subparallel, each valve rather uniformly sclerotized, covered with microtrichia 26a(25a) a. Stem vein with yellow or golden hair Simulium luggeri Nicholson & Mickel also: Scutum in anterodorsal view without stripes 26b a. Stem vein with golden brown to brown hair Simulium jenningsi Malloch also: Stem vein with golden brown to brown hair; hind femur (slide mounted) with scalelike setae 7-10 x longer than greatest width; genital fork with small patches of sclerotization adjacent to inner margin of each arm 27a(25b) a. Fore coxa brown Simulium tuberosum (Lundström) also: Stem vein with brown hair 27b a. Fore coxa yellowish to yellowish brown 28 28a(27b) a. Anal lobe in lateral view subquadrate, about as long as wide Simulium decorum Walker b. Frons grayish, dull, thinly pollinose 28b a. Anal lobe in lateral view subtriangular, wider than long 29 b. Frons grayish, dull, thinly pollinose 29a(28b) a. Anal lobe in lateral and ventral views unsclerotized along the anterior margin, although a dark line of setae can be present anteriorly Simulium irritatum Lugger, Simulium minutum Lugger, Simulium molestum Harris, Simulium truncatum (Lundström), Simulium venustum Say 29b a. Anal lobe in lateral and ventral views sclerotized along the anterior margin 30 30a(29b) a. Anal lobe in ventral view with a thin, smoothly curved sclerotized line along the anterior margin Simulium appalachiense Adler, Currie & Wood, Simulium conundrum Adler, Currie & Wood, Simulium perissum Dyar & Shannon, Simulium tuberosum (Lundström) [in part], Simulium vandalicum Dyar & Shannon b. Anal lobe with posterior area more weakly sclerotized but not in the form of a distint hyaline band 30b a. Anal lobe in ventral view with a wide anterior sclerotized band Simulium rostratum (Lundström), Simulium verecundrum Stone & Jamnback b. Anal lobe with sclerotized band separated from larger posterior sclerotized area by a thin unsclerotized hyaline band also: Anal lobe with outer anterolateral angle evenly rounded, not produced 31a(1b) a. Wing with basal section of radius bearing hair dorsally 32 31b a. Wing with basal section of radius without hair, or with few hairs, dorsally 50 32a(31a) a. Ventral plate in ventral view laterally compressed, keel like, with basal arms extended laterally 33 32b a. Ventral plate in ventral view not laterally compressed, but can be tapered posteriorly, with basal arms extented anteriorly 34 33a(32a) a. Ventral plate in lateral view with body somewhat pointed apically Simulium exulatum Adler, Currie & Wood, Simulium pilosum (Knowlton & Rowe), Simulium violator Adler, Currie & Wood b. Gonostylus in dorsal view with base forming 90-degree angle with narrowed portion 33b a. Ventral plate in lateral view with body broadly rounded apically Simulium bracteatum Coquillett b. Gonostylus in dorsal view with base forming a 45-degree angle with narrowed portion 34a(32b) a. Gonostylus in inner lateral view bulged well beyond spinule Simulium furculatum (Shewell) b. Dorsal plate with lip well-developed, and with flange (collar) about 3 x wider than lip at greatest width also: Ventral plate in ventral view with lateral margins convergent posteriorly 34b a. Gonostylus in inner lateral view not bulged 35 b. Dorsal plate with lip absent or lip poorly developed, or with flange (collar) about < 3 x wider than lip at greatest width 35a(34b) a. Gonostylus in ventral view narrow, uniformly tapered to pointed apex 36 35b a. Gonostylus in ventral view with medially directed, subtriangular flange 42 36a(35a) a. Paramere bearing 1 stout spine at midlength and 1-3 stout spines distally 37 b. Aedeagal membrane with long fine spines 36b a. Parameter without stout spine at midlength, but with 1 stout detached spine or more than 4 stout spines distally 38 b. Aedeagal membrane without long fine spines, although cluster of numerous short stout spines can be present 37a(36a) a. Ventral plate in ventral view with posterolateral finger-like lobe on each side Simulium annulus (Lundström) b. Ventral plate in ventral view not deeply concave posteriorly 37b a. Ventral plate in ventral view without posterolateral finger-like lobe on each side Simulium emarginatum Davies, Peterson & Wood b. Ventral plate in ventral view broad and short, deeply and broadly concave posteriorly 38a(36b) a. Basitarsus of hind leg with pedisulcus short and deep, its depth at least 1/3-1/2 width of segment Simulium johannseni Hart b. Antenna with pedicel distinctly shorter than basal flagellomere also: Ventral plate in ventral view broadly rounded posteriorly; scutum unicolorous, without stripes 38b a. Basitarsus of hind leg with pedisulcus typically long and shallow, its depth < 1/3 width of segment 39 b. Antenna with pedicel as long as or only slightly shorter than basal flagellomere 39a(38b) a. Paramere with spines small, the longest about 2-3 times longer than its basal width Simulium excisum Davies, Peterson & Wood 39b a. Paramere with spines long, the longest more than 3 times longer than its basal width 40 40a(39b) a. Paramere with longest spine at 3-5 x longer than its basal width Simulium innocens (Shewell) also: Ventral plate in lateral view pointed apically 40b a. Paramere with longest spine > 5 x longer than its basal width 41 41a(33a) a. Mesepimeral tuft brown Simulium anatinum Wood 41b a . Mesepimeral tuft silvery Simulium congareenarum (Dyar & Shannon) 42a(35b) a. Katepisternum with patch of golden hair dorsally Simulium gouldingi Adler, Currie & Wood 42b a. Katepisternum bare 43 also: Dorsal plate oblong to circular, with flanged collar; gonostylus in ventral view with medially directed flange variously produced, convex or only slightly concave posteriorly 43a(42b) a. Dorsal plate > 3 x longer than width at midpoint Simulium aestivum Davies, Peterson & Wood 43b a. Dorsal plate < 2 x as long as width at midpoint 44 44a(43b) a. Ventral plate in ventral view convex or straight posteriorly 45 44b a. Ventral plate in ventral view at least slightly concave posteriorly, sometimes with small tubercle extended into concavity
49 45a(44a) a. Body hair coppery brown Simulium burgeri Adler, Currie & Wood 45b a. Body hair, especially on scutum, at least partially golden, pale yellow, or silvery 46 46a(45b) a. Gonostylus in inner lateral view with spinule flush with posterior margin Simulium craigi Adler & Currie also: Ventral plate in ventral view subrectangular, about twice as wide as long; mesepimeral tuft pale yellow to golden 46b a. Gonostylus in inner lateral view with spinule anterior to posterior margin 47 47a(46b) a. Gonostylus in ventral and inner lateral views with outer margin bulged Simulium silvestre (Rubtsov) b. Dorsal plate typically subcircular beyond flanged collar 47b a. Gonostylus in ventral and inner lateral views with outer margin straight 48 b. Dorsal plate rather oval beyond flanged collar 48a(47b) a. Ventral plate in ventral view rounded posteriorly Simulium croxtoni Nicholson & Mickel 48b a. Ventral plate in ventral view rather truncated posteriorly Simulium fionae Adler 49a(44b) a. Ventral plate in terminal view with lip swollen Simulium quebecense Twinn
49b a. Ventral plate in terminal view with lip not appreciably swollen Simulium modicum Adler, Currie & Wood also: Gonostylus in ventral view with anterior margin of medial flange directed medially; ventral plate in ventral view with posterior margin not scalloped and with a proment central tubercle; basal arms straight or slightly bowed 50a(31b) a. Gonostylus about as long as gonocoxa, with 1 apical spinule, in inner lateral view conical, uniformly tapered to pointed apex Simulium meridionale Riley also: Ventral plate in ventral view subrectangular, about 2x wide as long 50b a. Gonostylus shorter to longer than gonocoxa, with 0-3 apical spinules, in inner lateral view neither conical nor uniformly tapered to pointed apex
51 51a(50b) a. Gonostylus shorter than gonocoxite Simulium tribulatum Lugger, Simulium vittatum Zetterstedt also: Gonostylus with 2-5 apical spinules; fore leg mostly brown or dark brown, with dull silvery patch on tibia; scutum in anterior view velvety black, with 2 variably distinct, grayish pruinose triangular patches 51b a. Gonostylus longer than gonocoxite 52 52a(51b) a. Gonostylus in inner lateral view with distinct basal or subbasal, rounded or spinelike lobe 53 52b a. Gonostylus in inner lateral view without distinct basal or subbasal lobe 56 53a(52a) a. Gonostylus with basal or subbasal lobe bearing, at most, fine hair on anterior surface Simulium rugglesi Nicholson & Mickel also: Gonostylus about 2 times as long as greatest width; ventral plate in ventral and terminal views with lateral margins serrated; gonostylus in inner lateral and ventral views with subbasal lobe narrow 53b a. Gonostylus with basal lobe bearing numerous short stout spines on anterior surface 54 also: Ventral plate in ventral view < 2.5x wide as long; scutum in anterior view with pair of pruinose patches anterolaterally 54a(53a) a. Ventral plate in lateral view with lip variably bulged posteriorly Simulium appalachiense Adler, Currie & Wood 54b a. Ventral plate in lateral view with lip directed medially or anteriorly 55 55a(54b) a. Ventral plate in lateral view with posterior margin directly anteriorly Simulium conundrum Adler, Currie & Wood also: Gonostylus in ventral view bulged on inner margin about 3/4 distance to its apex 55b a. Ventral plate in lateral view with posterior margin directly medially Simulium perissum Dyar & Shannon, Simulium tuberosum (Lundström), Simulium vandalicum Dyar & Shannon 56a(44b) a. Ventral plate in ventral view with deep medial cleft posteriorly, which is extended more than half distance to the anterior margin 57 b. Gonostylus in ventral view about 4 x as long as basal width 56b a. Ventral plate in ventral view convex, concave, or laterally compressed posteriorly, but without deep medial cleft 58 b. Gonostylus in ventral view < 4 x as long as basal width 57a(56a) a. Ventral plate in ventral view with outer lateral margins bowed outward Simulium innoxium Comstock & Comstock 57b a. Ventral plate in ventral view outer lateral margins covergent posteriorly also: margins of medial cleft subparallel Simulium pictipes Hagen 58a(56b) a. Ventral plate in ventral view with basal arms each bearing distinct lateral projection 59 b. Scutum with posterior 1/3 shiny and bearing fine indistinct hair also: Ventral plate in ventral view with lateral margins of body subparallel 58b a. Ventral plate in ventral view with basal arms each not bearing distinct lateral projection 60 b. If lateral projections present, then scutum with posterior 1/4 shiny and clothed with coarse hair 59a(58a) a. Ventral plate in lateral view with lip rather thin Simulium luggeri Nicholson & Mickel 59b a. Ventral plate in lateral view with lip thicker Simulium jenningsi Malloch also: Ventral plate in ventral view with space between basal arms somewhat V shaped 60a(68b) a. Ventral plate in ventral view with body rather broad, and lateral margins slightly divergent Simulium irritatum Lugger, Simulium minutum Lugger, Simulium molestum Harris, Simulium truncatum (Lundström), Simulium venustum Say b. Ventral plate in terminal view somewhat trilobed, about as long as wide 60b a. Ventral plate in ventral view with body laterally compressed, somwhat V or Y shaped 61 b. Ventral plate in terminal view slender, longer than wide 61a(60b) a. Ventral plate in ventral view broadly V shaped Simulium decorum Walker b. Ventral plate in lateral view large, with lip bluntly rounded 61b a. Ventral plate in ventral view narrowly Y shaped 62 b. Ventral plate in lateral view small, with lip rather pointed 62a(61b) a. Ventral plate in ventral view strongly Y shaped, slightly tapered posteriorly or strongly compressed (almost flattened) laterally Simulium murmanum Enderlein b. Ventral plate in lateral view with inner margin nearly straight 62b a. Ventral plate in ventral view rather V shaped Simulium rostratum (Lundström), Simulium verecundrum Stone & Jamnback b. Ventral plate in lateral view with inner margin produced as a prominent lip
Larvae
1a a. Gill of 2-3 filaments subequal in length and thickness, though thickened basally Simulium johannseni Hart [in part] also: Cocoon slipper shaped, covering most of pupal body 1b a. Gill of > 4 filaments 2 2a(1b) a. Gill of 4 filaments 3 2b a. Gill of > 5 filaments 10 3a(2a) a. Cocoon with long anterodorsal projection 4 3b a. Cocoon without long anterodorsal projection, although anterodorsal margin may be ragged 5 4a(3a) a. Gill in lateral view with dorsalmost filaments divergent basally from ventralmost filament at angle of > 50 degrees Simulium silvestre (Rubtsov) also: Head and thorax with rounded, irregularlly distributed microtubercles; gill with filaments of dorsal pair branched more in vertical plane 4b a. Gill in lateral view with dorsalmost filaments divergent basally from ventralmost filament at angle of < 50 degrees Simulium craigi Adler & Currie also: Cocoon with anterodorsal projection long, slender, not bifurcate 5a(3b) a. Gill with all filaments swollen basally Simulium johannseni Hart [in part] 5b a. Fill with 0-1 of 4 filaments swollen basally 6 6a(5b) a. Gill in lateral view with dorsalmost filament strongly divergent from other 3 filaments Simulium bracteatum Coquillett, Simulium exulatum Adler, Currie & Wood, Simulium pilosum (Knowlton & Rowe), Simulium violator Adler, Currie & Wood 6b a. Gill in lateral view with dorsalmost filament not strongly divergent from other 3 filaments 7 7a(6b) a. Gill filaments (slide mounted) with reticulate surface pattern Simulium quebecense Twinn 7b a. Gill filaments (slide mounted) with transverse furrows 8 8a(7b) a. Gill in lateral view with filaments divergent dorsoventrally at base Simulium annulus (Lundström) also: Gill with ventral pair of filaments branched in vertical plane; gill typically with at least 1 trunk > 2x longer than wide; dorsal trunk 1.5-2.0 x thicker than ventral trunk, and bases of dorsal filaments up to 2 x thicker than bases of ventral filaments 8b a. Gill in lateral view with filaments in compact bundle at base, not strongly divergent dorsoventrally 9 9a(8b) a. Gill with filaments of each pair branched in verticle plane Simulium modicum Adler, Currie & Wood also: Head and thorax with scattered, small microtubercles 9b a. Gill with filaments of each pair branched in horizontal plane Simulium aestivum Davies, Peterson & Wood also: Head and thorax with densely distributed, large microtubercles 10a(9a) a. Gill of 5-6 filaments 11 10b a. Gill of > 8 filaments 15 11a(9b) a. Cocoon with anterodorsal long projection 12 11b a. Cocoon without an anterodorsal projection 13 12a(11b) a. Gill with at least 1 pair of filaments branched in vertical plane Simulium gouldingi Adler, Currie & Wood 12b a. Gill with each pair of filaments branched in horizontal plane Simulium excisum Davies, Peterson & Wood also: Head and thorax with microtubercles rather flattened, uniformly spaced 13a(11b) a. Gill filaments in dorsal view divergent laterally Simulium rostratum (Lundström), Simulium verecundrum Stone & Jamnback b. Head and thorax with uniformly arranged microtubercles 13b a. Gill filaments in dorsal view aligned more or less in vertical plane 14 b. Head and thorax smooth or with variously arranged microtubercles 14a(13b) a. Gill typically > 0.5 x long as pupal body, and with all filaments subequal in thickness Simulium irritatum Lugger, Simulium minutum Lugger, Simulium molestum Harris, Simulium truncatum (Lundström), Simulium venustum Say b. Abdomen of young pupa typically other than dark gray or blackish 14b a. Gill often about 0.5 x long as pupal body, and with filaments decreasing in thickness from dorsalmost to ventralmost Simulium conundrum Adler, Currie & Wood, Simulium tuberosum (Lundström), Simulium vandalicum Dyar & Shannon b. Abdomen of young pupa dark gray or blackish also: Head and thorax with numerous microtubercles 15a(14b) a. Gill of 8 filaments 16 15b a. Gill of > 9 filaments 21 16a(15a) a. Cocoon with anterodorsal projection (sometimes short) also: Gill of 1 pair of filaments and 2 triads, arranged 2+3+3 17 16b a. Cocoon without anterodorsal projection 19 17a(16a) a. Gill in lateral view with dorsalmost filament not strongly divergent from other filaments Simulium furculatum (Shewell) [in part] b. Filaments not widely splayed c. Filaments in dorsal view subparallel also: Cocoon with anterodorsal projection very short 17b a. Gill in lateral view with dorsalmost filament divergent from other filaments 18 b. If not divergent, then filaments widely splayed c. Filaments in dorsal view divergent laterally 18a(17b) a. Gill with dorsalmost filament typically divergent at nearly 90-degree angle Simulium burgeri Adler, Currie & Wood, Simulium fionae Adler 18b a. Gill with dorsalmost filament typically diverent at less than 90-degree angle Simulium croxtoni Nicholson & Mickel 19a(16b) a. Gill with 4 pairs of petiolate filaments Simulium rugglesi Nicholson & Mickel also: Gill in lateral view typically more than 0.5 x length of pupal body, in dorsal view with filaments laterally divergent; head dorsally with microtubercles irregularly distributed 19b a. Gill with at least 1 filament arising independently from base, or with at least 1 trio of filaments on a common trunk or petiole 20 20a(19b) a. Cocoon loosely woven, with many small gaps, especially anteriorly Simulium decorum Walker b. Gill with at least 1 filament arising independently from base 20b a. Cocoon tightly woven, without gaps Simulium furculatum (Shewell) [in part] b. Gill typically without filaments arising singly from base also: Gill with dorsal trunk giving rise to 2 filaments 21a(15b) a. Gill of 9-12 filaments 22 21b a. Gill of > 13 filaments 28 22a(21a) a. Cocoon with anterodorsal projection 23 also: Thoracic trichomes < 10 in number 22b a. Cocoon without anterodorsal projection 24 23a(22a) a. Gill of 10 filaments Simulium innocens (Shewell) 23b a. Gill of 12 filaments Simulium anatinum Wood, Simulium congareenarum (Dyar & Shannon) 24a(22b) a. Gill of 11-12 filaments Simulium luggeri Nicholson & Mickel also: Gill not basally swollen; cocoon slipper shapped or slightly shoe shapped, with 1 large anterior aperature per side; pleural region of Ab8-9 with unbranched setae 24b a. Gill of 9-10 filaments 25 25a(24b) a. Cocoon slipper or shoe shaped Simulium jenningsi Malloch also: Cocoon with 1 or more large anterior aperatures per side; gill with reticulate surface sculpture, > 1/3 x length of pupal body; head and thorax with rounded microtubercles 25b a. Cocoon boot shaped 26 26a(25a) a. Gill of 10 filaments, not arranged in an open rosette Simulium murmanum Enderlein b. Cocoon with large anterior loops of silk forming aperatures 26b a. Gill of 9 filaments, arranged in an open rosette in anterior view 27 b. Cocoon with small gaps throughout 27a(26a) a. Gill with all filaments inflated basally Simulium pictipes Hagen 27b a. Gill with, at most, only some filaments inflated basally Simulium innoxium Comstock & Comstock 28a(21b) a. Gill of 13-16 filaments Simulium tribulatum Lugger, Simulium vittatum Zetterstedt also: Cocoon well-formed, slipper shaped, densely woven, without gaps; abdomen with ventral recurved hooks and terminal spines no larger than dorsal recurved hooks 28b a. Gill of 22-26 filaments Simulium meridionale Riley also: Gill filaments < 0.5 x length of pupal body; cocoon typically shoe shaped, with anterior collar
References
1a a. Postgenal cleft extended less than half the distance from the posterior tentorial pits to hypostomal groove 2 1b a. Postgenal cleft extended half or more the distance from the posterior tentorial pits to hypostomal groove, in doubtful cases, abdomen gradually expanded posteriorly, or frontoclypeal apotome with negative head-spot pattern or with head spots faint, obscure, or apparently absent 16 2a(1a) a. Antenna shorter than stalk of labral fan, or extended beyond the apex of stalk by no more than half the length of the distal article Simulium tribulatum Lugger, Simulium vittatum Zetterstedt b. Ab9 in lateral view with ventral tubercles typically inconspicuous also: Postgenal cleft subquadrate, with anterior margin straight or rounded; antenna concolorous or with 1-2 pale spots on medil article; gena with spots, when visible, darker than surrounding pigment, althought 1 spot sometimes paler; frontoclypeal apotome without dark pigment posteriorly, or if with dark pigment, then typically rather equally distributed around head spots; anterolateral head spots strong relative to medial head spots; abdomen typically without dorsocentral and lateral, longitudinal unpigmented stripes, or if dorsocentral strip present, then not continuous; gill histoblast of 14-16 filaments 2b a. Antenna extended beyond the stalk of labral fan by more than half the length of the distal article 3 b. Ab9 in lateral view with ventral tubercles conspicuous 3a(2b)
a. Antenna with medial article bearing > 3 pale rings (slide mounting may be require to see) 4 b. Gill histoblast of 3-12 filaments 3b a. Antenna with medial article not bearing pale rings 7 b. Gill histoblast of 4 or 6 filaments 4a(3a) a. Hypostoma with lateral teeth largest, extended anteriorly beyond the median tooth 5 b. Gill histoblast of 3 or 5-12 filaments also: typically of small streams 4b a. Hypostoma with median and lateral teeth subequal in prominence, extended anteriorly to about the same level 6 b. Gill histoblast of 4 slender filaments also: typically of wider streams and rivers 5a(4a) a. Postgenal cleft slightly wider than long, markedly biarctate Simulium innocens (Shewell) b. Gill histoblast of 10 filaments also: Head typically pale yellowish, without brown flecks 5b a. Postgenal cleft about as wide as long, rounded or truncated anteriorly, at most weakly biarctate Simulium anatinum Wood, Simulium congareenarum (Dyar & Shannon) b. Gill histoblast of 12 filaments also: Abdomen with reddish pigment arranged either in bands or in 2 dorsal longitudinal rows of spots 6a(4b) a. Postgenal cleft strongly biarctate Simulium annulus (Lundström) 6b a. Postgenal cleft with anterior margin straight or rounded, if biarctate, then abdomen spotted, typically not banded Simulium emarginatum Davies, Peterson & Wood also: Gill histoblast typically with short trunks of approximately equal length 7a(6b) a. Anterolateral head spots on each side not closely approximated to one another Simulium excisum Davies, Peterson & Wood b. Hypostoma (slide mounted) with anterolateral margin of ventral wall bearing longitudinal sulcus also: Hypostoma with teeth not conspicuously arranged in 3 groups, median and lateral teeth extended anterorily to about the same level; gill histoblast of 6 filaments 7b a. Anterolateral head spots on each side closely approximated to one another 8 b. Hypostoma (slide mounted) with anterolateral margin of ventral wall not bearing longitudinal sulcus 8a(7b) a. Frontoclypial apotome with all head spots except anteromedial and sometimes anterolateral head spots enclosed in nearly solid dark pigment Simulium aestivum Davies, Peterson & Wood 8b a. Frontoclypial apotome with head spots typically not enclosed in dark pigment except sometimes centrally, or if enclosed, then completely and often faintly so, or with pale yellowish area posterior and slightly lateral to posteromedial head spot 9 9a(8b) a. Postgenal cleft parallel sided, with rather straight anterior margin 10 b. Rectal papillae of 3 simple lobes 9b a. Postgenal cleft in shape of small notch or inverted U, with broadly rounded or pointed anterior margin 13 b. Rectal papillae of 3 simple or compound lobes 10a(9a) a. Frontoclypial apotome with head spots typically enclosed in dark pigment except for pale yellowish area posterior and slightly lateral to posteromedial head spot Simulium violator Adler, Currie & Wood 10b a. Frontoclypial apotome with head spots not enclosed in pigment, or if so, then only centrally 11 11a(10b) a. Head pale yellowish, typically with little or no trace of darker pigment surrounding head spots Simulium exulatum Adler, Currie & Wood 11b a. Head brownish yellow or brownish orange, with or without some darker pigment surrounding head spots 12 12a(11b) a. Postgenal cleft rather straight anteriorly, not biarctate, typically extended slightly < 1/2 distance to the hypostoma groove Simulium bracteatum Coquillett b. Frontoclypeal apotome sometimes with dark pigment surrounding more than part of posteromedial head spot 12b a. Postgenal cleft rather straight anteriorly, not biarctate, extended about 1/3 distance to the hypostoma groove Simulium pilosum (Knowlton & Rowe) b. Frontoclypeal apotome with, at most, a small amount of dark pigment surrtounding more than part of posteromedial head spot 13a(9b) a. Postgenal cleft surrounded by faint brownish pigment in shape of H, contrasting with pale yellowish pigment of ventral head Simulium silvestre (Rubtsov) [in pat] b. Abdominal cuticle posterodorsally with numerous dark, unbranched setae (sometimes broken off, but visible by viewing slide-mounted piece of cuticle under compound microscope) 13b a. Postgenal cleft not surrounded by brownish pigment in shape of H 14 b. Abdominal cuticle posterodorsally without numerous dark, unbranched setae 14a(13b) a. Gill histoblast of 6 filaments Simulium gouldingi Adler, Currie & Wood [in part] 14b a. Gill histoblast of 4 filaments, with ventral trunk < 3x length of dorsal trunk 15 15a(14b) a. Frontoclypeal apotome with head spots typically encompassed by faint pigment in form of an inverted U Simulium craigi Adler & Currie [in part] b. Postgenal cleft rounded anteriorly 15b a. Frontoclypeal apotome with head spots typically free of surrounding pigment in form of inverted U Simulium modicum Adler, Currie & Wood b.Postgenal cleft rounded or tapered anteriorly, with widest point near midlength also: head yellowish brown to brownish orange 16a(1b) a. Postgenal cleft typically broad anteriorly, and reaching or nearly reaching hypostomal groove 17 b. Abdominal cuticle (slide mounted) posterodorsally with numerous tubular or multiply branched, pale or dark setae, often giving abdomen minutely hairy appearance 16b a. Postgenal cleft not reaching hypostomal groove, or if so, then only by narrowed or pointed extension 18 b. Abdominal cuticle (slide mounted) posterodorsally with or without numerous tubular or multiply branched, pale or dark setae
17a(16a) a. Ab1-5 with circlet of tubercles Simulium meridionale Riley b. Gill histoblast of > 20 filaments 17b a. Ab1-5 without circlet of tubercles Simulium rugglesi Nicholson & Mickel b. Gill histoblast of 8 filaments also: Abdominal cuticle (slide mounted) with numerous pale, multiply branched setae 18a(16b) a. Postgenal cleft large, bulbous, often nearly circular in outline, about as long as wide, not gradually tapered (although sometimes slightly pointed) anteriorly 19 b. Frontoclypeal apotome with positive head-spot pattern 18b a. Postgenal cleft of various sizes and shapes, but typically not bulbous or circular in outline, typically longer than wide, point, rounded, or gradually tapered anteriorly 23 b. Frontoclypeal apotome with positive or negative head-spot pattern, or with head spots apparently absent
19a(18a) a. Ab9, in lateral view, without ventral tubercles, although wrinkle of cuticle often present 20 also: Head typically yellowish brown, with distinct head spots; antenna extended beyond apex of stalk of labral fan; abdomen expanded rather abruptly at Ab5; gill histoblast of 10-12 short to long filaments, but not strongly annulated 19b a. Ab9, in lateral view, with ventral tubercles minute and often slender, or conspicuous and conical 21 20a(19a) a. Gill histoblast of 12 filaments Simulium luggeri Nicholson & Mickel [in part] 20b a. Gill histoblast of 10 filaments, (slide mounted) with filaments bearing reticulate surface sculpture Simulium jenningsi Malloch [in part] 21a(19b) a. Gill histoblast of 2-4 filaments, with all filaments mildly to strongly swollen basally Simulium johannseni Hart also: Body with brownish bands of subequal intensity; frontoclypeal apotome with head spots free of dark surrounding pigment, or enclosed and sometimes obscured with mottled brown pigment 21b a. Gill histoblast of 8-12 filaments 22 22a(21b) a. Gill histoblast of 12 filaments Simulium luggeri Nicholson & Mickel [in part] 22b a. Gill histoblast of 10 filaments, (slide mounted) with filaments bearing reticulate surface sculpture Simulium jenningsi Malloch [in part] 23a(22b)
a. Ab9 with a pair of conspicuous conical ventral tubercles 24 b. Frontoclypeal apotome with positive head spot pattern 23b a. Ab9 without a pair of conspicuous conical ventral tubercles, or at most with a pair of small rounded tubercles 31 b. Frontoclypeal apotome with positive or negative head spot pattern, or with spots apparently absent 24a(23a) a. Frontoclypeal apotome with medial brown stripe (sometimes faint) extended anteriorly beyond the antennal bases Simulium croxtoni Nicholson & Mickel b. Abdominal cuticle (slide mounted) posterodorsally with numerous minute, unbranched, dark setae c. Gill histoblast of 8 filaments 24b a. Frontoclypeal apotome without medial brown stripe extended anteriorly 25 b. Abdominal cuticle (slide mounted) posterodorsally with numerous or scattered, transparent or dark, unbranched or multiply branched setae c. Gill histoblast of 4-8 filaments 25a(24b) a. Body greenish gray to reddish, with pigment on Ab1 darker and denser than on subsequent 3 segments Simulium quebecense Twinn b. Gill histoblast of 4 filaments with reticulate surface sculpture 25b a. Body variously pigmented, with pigment on Ab1 subequal in intensity to that on subsequent 3 segments 26 b. Gill histoblast of 4-8 filaments, if 4 filaments, then not with reticulate surface sculpture 26a(25b) a. Abdominal cuticule (slide mounted) dorsally with numerous dark, multiply branched setae Simulium fionae Adler b. Gill histoblast of 8 filaments 26b a. Abdominal cuticule (slide mounted) dorsally with dark or pale unbranched setae, or if with multiply branched setae, these pale, typically visible only with phase contrast 27 b. Gill histoblast of 4-8 filaments 27a(26b) a. Abdominal cuticule (slide mounted, phase contrast) dorsally with numerous unpigmented, multiply branched setae Simulium burgeri Adler, Currie & Wood b. Gill histoblast of 8 filaments 27b a. Abdominal cuticule (slide mounted) dorsally with numerous or scattered, dark or pale unbranched setae 28 b. Gill histoblast of 4-8 filaments 28a(27b) a. Abdominal cuticule (slide mounted) posterodorsally with scattered pale setae 29 b. Gill histoblast of 4-6 filaments 28b a. Abdominal cuticule (slide mounted) posterodorsally with numerous dark setae 30 b. Gill histoblast of 4-8 filaments 29a(28a) a. Frontoclypeal apotome with head spots encompassed by faint pigment in form of an inverted U Simulium craigi Adler & Currie [in part] b. Gill histoblast of 4 filaments 29b a. Frontoclypeal apotome with head spots typically free of surrounding pigment in form of an inverted U, although anterior spots sometimes surrounded by pigment Simulium gouldingi Adler, Currie & Wood [in part] b. Gill histoblast of 6 filaments, each subequal in thickness also: Postgenal cleft extended only slightly more than half the distance to the hypostomal groove 30a(28b) a. Postgenal cleft surrounded by faint brownish pigment in shape of H, contrasting with pale yellowish pigment of ventral head Simulium silvestre (Rubtsov) [in part] b. Gill histoblast of 4 filaments 30b a. Postgenal cleft not surrounded by faint brownish pigment in shape of H Simulium furculatum (Shewell) b. Gill histoblast of 8 filaments also: Antenna shorter than apex of labral fan, or extended beyond he apex of labral fan by no more than half the length of the distal article; head yellowish to brownish yellow, with head spots bold, sometimes surrounded, at least centrally, by dark pigment; body pale grayish to reddish 31a(23b) a. Head yellowish to brownish yellow, with head spots bold, sometimes surrounded, at least centrally, by dark pigment Simulium furculatum (Shewell) b. Abdominal cuticle (slide mounted) posterodorsally with numerous dark setae c. Body pale grayish to reddish d. Gill histoblast of 8 filaments 31b a. Head variouslly pigmented, with head spots variouslly expressed 32 b. Abdominal cuticle (slide mounted) posterodorsally with scattered pale or dark setae c. Body variously pigmented d. Gill histoblast of 6-16 filaments 32a(31b) a. Hypostoma with median tooth broader than, and extended anteriorly beyond, the lateral teeth, with the anterolateral margin typically somewhat rounded 33 b. Postgenal cleft subtriangular c. Large, typically > 8.0 mm d. Gill histoblast of 8, 9 or 15 filaments
32b a. Hypostoma with median and lateral teeth subequal in width and extended anteriorly to same level, with the anterolateral margin abruptly angled 34 b. Postgenal cleft of various shapes c. Smaller, typically < 8.5 mm or longer d. Gill histoblast of various numbers of filaments 33a(32a) a. Gill histoblast with, at most, only some filaments inflated basally Simulium innoxium Comstock & Comstock 33b a. Gill histoblast with all filaments inflated basally Simulium pictipes Hagen 34a(32b) a. Head with negative head-spot pattern or without spots 35 b. Gill histoblast of 6 or 8 filaments
34b a. Head with positive head-spot pattern, although some head spots can be weak, absent, or negative, or if with complete negative head-spot pattern, then body black or gill histoblast of 10 or 12 filaments 36 b. Gill histoblast of 6-16 filaments 35a(34a) a. Frontoclypeal apotome with dark pigment typically restricted to central, elongate or H-shaped pattern Simulium decorum Walker b. Subesophageal ganglion typically not ensheathed with pigment c. Gill histoblast of 8 filaments also: Body brownish; head typically brownish laterally and ventrally 35b a. Frontoclypeal apotome with dark pigment either absent or typically not forming central, elongate or H-shaped pattern Simulium irritatum Lugger [in part], Simulium minutum Lugger, Simulium molestum Harris, Simulium rostratum (Lundström), Simulium truncatum (Lundström), Simulium venustum Say, Simulium verecundrum Stone & Jamnback b. Subesophageal ganglion with or without ensheathed pigment c. Gill histoblast of 6 filaments 36(34b) a. Abdomen rather gradually expanded posteriorly Simulium murmanum Enderlein b. Large species, typically > 6 mm c. Gill histoblast of 10 filaments also: Frontoclypeal apotome with posterior head spots typically encompassed by brown, subtriangular patch of pigment 36b a. Abdomen rather abruptly expanded at Ab5 37 b. Small species, typically < 6 mm c. Gill histoblast of 6 filaments 37a(36b) a. Body dark gray or blackish, with pigment rather uniformly distributed, or if banded, then intersegmental areas mottled with grayish pigment Simulium conundrum Adler, Currie & Wood b. Head brownish orange, with head spots often obscure, or with anterolateral head spots darkest 37b a. Body gray to brown, with pigment distributed in bands 38 b. Head yellowish brown to brownish orange, with head spots variously distinct 38a(37b) a. Body with whitish area on posterior half of thorax, contrasting with grayish pigment anteriorly and posteriorly Simulium appalachiense Adler, Currie & Wood 38b a. Body with smaller whitish area on thorax Simulium perissum Dyar & Shannon, Simulium vandalicum Dyar & Shannon, Simulium tuberosum (Lundström)
Adler PH, Currie DC, Wood DW. 2004. The black flies (Simuliidae) of North America. Cornell University Press: Ithaca, New York. xv + 941 p.
Page created: December 01, 2013; Last updated: December 4, 2013 (EB)