Aquatic Insects of Michigan

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

Aquatic and Semiaquatic Diptera of Michigan

Keys to the aquatic Diptera of Michigan are currently in preparation; some families now have keys to the genera or species. Several pages to some genera can be used, and are thus available by following the links, including: Chironomidae (Chironominae: Nilothauma, Stenochironomus; Orthocladiinae: Brillia, Paraphaenocladius). Other keys to genera in certain taxa will appear in the near future.

Key to Adults
(adapted from Merritt and Webb 2008)

1a a. Antennae generally longer than the thorax, usually with 4 or more freely articulated flagellomeres, with the apical segments usually not consolidated into a stylus or arista b. Maxillary palpi with 3-5 segments Nematocera, 3
1b a. Antennal flagellum usually consolidated into a single coumpound segment typically bearing a terminal to the dorsal stylus or arista b. Palpus with 2 or fewer segments Brachycera, 14

Nematocera

2a Wings with a network of fine crease-like lines between the true veins, and with the number of main veins more or less reduced b. Anal lobe of wing strongly projecting also: Flagellum with 11-13 flagellomeres, terminal segment not lengthened Blephariceridae, Blepharicera Macquart
2b Wings without a network of crease-like lines between the main veins, and the number of main veins not reduced b. Anal lobe of wing not produced as above 3

3a(3b) a. Mesonotum with an entire V-shaped suture or impression 4
3b a. Mesonotum suture transverse, not V-shaped, or absent 5

4a(3a) a. Wings with 2 anal veins reaching the margin b. Legs long and slender Tipuloidea
4b a. Wings with a single anal vein reaching the margin b. Legs variable also: Halter with a prehalter (basal appendage) anterior to their base; wings slender, with 9-10 longitudinal veins including a 4-branched radius and one anal vein reaching the margin; slender flies with very long legs, sometimes conspicuously banded with white; abdomen long Ptychopteridae

5a(3b) a. Costa extending around margin of wing, though weaker beyond apex 6
5b a. Costa extending at or near the apex of the wing 11

6a(5b) a. Wings with 7 longitudinal veins reaching the margin b. Antennae subequal to head length, and shorter than palpi, with basal segments of flagellum thickened and calvate, the remaining segments filiform also: Small flies (3-4 mm) Thaumaleidae, Androprosopa Mik
6b a. Wings with at least 9 longitudinal veins reaching the margin b. Antennal flagellum uniformly filiform or beadlike 7

7a(6b) a. Wings short annd broad, pointed apically, usually densely hairy and held rooflike over the body when at rest b. Crossveins absent except near base of wing Psychodidae
7b a. Wings long, or if broad, the apex very broadly rounded b. Wings held flat over the abdomen when at rest, and not densely hairy b. Crossveins present 8

8a(7b) a. Proboscis elongated, extending between their legs b. Scales present on wings margins and veins and usually on the body Culicidae
8b a. Proboscis short, extending little beyond the clypeus b. Scales absent on wing veins 9

9a(8b) a. Apical wing veins (R1-R3) strongly arched Dixidae
9b a. Apical wing veins (R1-R3) straight or nearly so 10

10a(9b) a. R1 of wing ending in costa closer to Sc than R2 Corethrellidae, Corethrella Coquillett, 1902
10b a. R1 of wing ending in costa closer to R2 than Sc Chaoboridae

11a(5b) a. Ocelli present b. Vein R2 extending from apex of R1 to middle of R3, two medial veins with short petiole basally Axymyiidae, Axymyia furcata McAtee 1921
11b a. Ocelli absent b. Wing veins not as above 12

12a(11b) a. Wings broad, anterior veins strong with posterior veins weak and poorly developed b. Antennae shorter than thorax, males never plumose c. Dark or variously colored flies with humpbacked appearance, rarely over 6 mm in length Simuliidae
12b a. Wings narrower and long, the posterior veins usually strong b. Antennae generlaly longer than thorax, males often plumose 13

13a(12b) a. Postnotum with or without a median longitudinal groove b. If groove absent (subfamily Podonominae), then crossvein m-cu present c. M vein unbranched d. Eyes dichoptic Chironomidae
13b a. Postnotum without median longitudinal groove b. Crossvein m-cu absent c. M usually with two branches, but M2 often difficult to see, sometimes completely obsolescent d. Eyes holoptic or dichoptic Ceratopogonidae

Brachycera

14a(1b) a. Tarsi with 3 nearly equal pads under tarsal claws (empodium pulvilliform) 15
14b a. Tarsi with 2 nearly equal pads under tarsal claws (empodium hairlike or absent) 18

15a(14a) a. Costa ending at or near wing tip b. Tibiae without spurs Stratiomyidae
15b a. Costa continuing well past wing tip, often around the entire posterior margin of the wing b. At least mesotibiae with spurs 16

16a(15b) a. Ant3 compact, not annulated Athericidae, Atherix Meigen
16b a. Ant3 annulated with 3-8 apparent segments 17

17a(16b) a. Upper and lower calypteres large, subequal in size b. Ab1 tergite with deep medial notch in posterior margin Tabanidae
17b a. Lower calypter scarcely developed b. Ab1 tergite without medial notch also: Crossvein r-m positioned at basal forth to third of cell d; males lacking aedeagal tines; uncommon Pelecorhychidae

18a(14b) a. Anal cell long, closed just before margin of wing, therefore petiolate b. A spurious (false) vein present running obliquely between veins R4+5 and M1+2 Syrphidae
18b a. Anal cell short, transverse, oblique, or convex apically, or rarely absent b. No spurious vein present between veins R4+5 and M1+2 19

19a(18b) Ptilinal (frontal) suture entirely absent b. Frons uniformly sclerotized c. Alula weak 20
19b a. Ptilinal (frontal) suture present b Frons divided into distinct regions by ptilinal suture c. Alula well developed 21

20a(19a) a. Anterior crossvein (r-m) situated at or before the basal fourth of wing b. 1st M2 and 2nd M2 cells united to form one long cell c. Vein R4+5 not branched Dolichipodidae
20b a. Anterior crossvein (r-m) situated far beyond basal fourth of wing b. 1st M2 and 2nd M2 cells separated c. Vein R4+5 usually branched (Fig. 22.245) Empididae

21a(19b) a. Ant2 without a longitudinal seam on its upper outer edge b. Mesonotum without a complete transverse suture c. Calypter (squama) small Acalypterate flies, 22
21b a. Ant2 with a longitudinal seam on its upper outer edge b. Mesonotum usually with complete transverse suture c. Calypter (squama) large Calypterate flies, 24

22a(21a) Costa ending near middle of wing b. Radial veins strongly thickened and crowded near anterior margin of wing Phoridae
22b a. Costa extending at least to apex of wing b. Radial veins not thickened and crowded anteriorly 23

23a(22b) a. Costa entire (not fractured) b. Subcosta complete, ends in costa also: Vein R1 ending at middle of costa; femora with strong bristles Sciomyziidae
23b a. Costa fractured just before end of subcosta and at humeral crossvein b. Subcosta usually incomplete, not reaching costa also: Anal cell absent Ephydridae

24a(21b) a. Mesonotum with 3 black complete longitudinal stripes on a gray background Sarcophagidae, Fletcherimyia fletcheri (Aldrich, 1916)
24b a. Mesonotum without stripes or with 4 incomplete stripes 25

25a(24b) a. Lower calypter longer than upper calypter b. Transverse suture complete Muscidae
25b a. Lower calypter not longer than upper calypter b. Transverse suture incomplete to nearly complete Scathophagidae

Pupae
(adapted from Merritt and Webb 2007, Borkent 2012)

1a a. Pupa free, not covered by last larval skin, although cocoon may be present 2
1b a. Pupa contained within last larval skin, which is heavily sclerotized 21

2a(1a) a. Antennal sheaths generally elongate, lying over the eyes and extending to or beyond the base of the wing sheaths c. Prothoracic respiratory organs or spiracles usually conspicuous 3
2b a. Antennal sheaths short, directed posteriorly and laterally, not reaching the wing base c. Prothoracic respiratory organs or spiracles rudimentary or absent in most cases x

3a(2a) a. Pupa usually enclosed in a fibrous, cone-shaped or slipper-like cocoon b. Respiratory organs consisting of numerous filaments projecting from open end of cocoon Simuliidae
3b a. Pupa not enclosed in cocoon, although it may be enclosed in silken tube or case made out of various materials b. Respiratory organs not as above 4

4a(3b) a. Pupa generally convex in shape, attached limpet-like to rocks in bed of stream 5
4b a. Pupa variable in shape, but not attached to rocks in bed of stream 6

5a(4a) a. Pupa flattened, shield-shaped b. Respiratory organs simple, cylindrical or ovoid in shape Psychodidae [in part]
5b a. Pupa more convex b. Respiratory organs usually with 4 simple lamellae (thin plates) Blephariceridae

6a(4b) a. Leg sheaths straight and projecting beyond ends of wing sheaths b. Caudal (anal) end of pupa not paddle-shaped, often forked, lobed and/or spined, never cylindrical with 3 terminal setae 7
6b a. Leg sheaths often curved or folded and projecting little, if any, beyond ends of wing sheaths, but if straight and projecting beyond ends of wing sheaths, then antennal sheath small, ending before base of wing sheath b. Or caudal lobes cylindrical with 3 terminal setae, otherwise, caudal end of pupa terminating in paddle-like structure also: Pupae commonly found in open water 8

7a(6a) a. One prothoracic respiratory organ longer than body of pupa, other organ short Ptychopteridae
7b a. Both prothoracic respiratory horns distinctly shorter than length of pupa, usually subequal in length Tipuloidea

8a(6b) a. Tergites of abdomen with acute posterolateral angles b. Thorax formed into numerous ridges and hollows also: abdomen with open spiracles on at least Ab5-7 Thaumaleidae, Androprosopa Mik
8b a. Tergites of abdomen without acute posterolateral angles; thorax not strongly ridged; combination of characters not as above 9

9a(8b) a. Wing sheaths extending to nearly mid-length of pupa b. Leg sheaths short, straight, and superimposed c. Robust pupa, under 4 mm in length Psychodidae
9b a. Wing sheaths ending distinctly before mid-length of pupa b. Leg sheaths otherwise c. Body elongate, length variable 10

10a(9b) a. Apex of abdomen with characteristic pair of paddles, each with an articulated base and with at least one medial, elongate rib supporting membrane (in many there are additional lateral, thickened margins) 11
10b a. Apex of abdomen either blunt or with pair of projections, each of which is fixed basally (except in the Chironomidae genus Lasiodiamesa Kieffer), with or without membrane, and lacking supporting ribs (including Lasiodiamesa) 12

11a(10a) a. Labrum, mandibles, maxillae elongate, extending posteriorly between separated forelegs to apex of wings and then curving anterodorsally along margin of wing Culicidae
11b a. Labrum, mandibles, maxillae short, not extending posteriorly beyond forecoxae; apices of forelegs abutting Chaoboridae

12a(10b) a. Palpus directed laterally b. Respiratory organ either multibranched, undivided or absent c. Terminal process with or without at least one elongate lateral seta (some with many setae or cuticular extensions as a marginal fringe), if elongate seta absent, then either without respiratory organ or respiratory organ without exterior opening Chironomidae
12b a. Palpus directed posteriorly, posteromedially or anteromedially b. Respiratory organ present and undivided, either with pores or with terminal funnel-shaped opening, or as a flattened almost disc-shaped structure c. Terminal process with or without a single elongate lateral seta (some with additional small sensilla) 13

13a(12b) a. Respiratory organ with at least some apical pores (many with additional subapical pores) b. Exuviae with face like a mask, retaining the original shape of the whole pupa Ceratopogonidae
13b a. Respiratory organ with a broad, open apex, or flattened, almost disc shaped and with peripheral pores (or at least pore-like structures) (peruviana species group of Corethrella Coquillett) b. Exuviae with face reconfigured, with the ocular lobes folded longitudinally against the dorsal apotome and with a sharp transverse bend between the dorsal apotome and clypeus 14

14a(13b) a. Palpus directed posteromedially, with apices well separated medially b. Metanotum divided medially by posteriorly projecting mesonotum Corethrellidae, Corethrella Coquillett, 1902
14b a. Palpus directed anteromedially, with apices abutting or overlapping medially b. Metanotum continuous medially, undivided Dixidae

15a(3b) a. Pupa short and robust b. Prothoracic respiratory organs or horns greatly elongated 16
15b a. Pupa more elongate b. Prothoracic respiratory organs shorter and less conspicuous 17

16a(15a) a. Abdomen with elongate lateral spiracular processes b. Pair of diverging sutures absent on ventral side of head Empididae [in part]
16b a. Abdomen without elongate lateral spiracular processes b. Pair of sutures present on ventral side of head running from apical cephalic tubercle, then diverging, and extending to behind the base of antennae on each side Dolichipodidae

17a(15b) a. Dorsal opening of thoracic spiracle generally directed along anterior-posterior axis of pupa b. Prominent pit mediolateral to each spiracle c. Abdominal segments 2-7 with encircling fringe of spines arranged in 1 or 2 series, the anterior series usually distinctly shorter (and sometimes stouter) than the posterior series Tabanidae
17b a. Dorsal opening of thoracic spiracle directed transversely (left to right) to axis of pupa and without a pit mediolateral to each spiracle b. Not as above c. Not as above 18

18a(17b) a. Frontal plate with ventrally directed respiratory horn and covered with strong spines b. Elongate tail-like process on abdominal segment 8 Axymyiidae, Axymyia furcata McAtee 1921
18b a. Frontal plate lacking respiratory horn and strong spines b. Elongate tail-like process absent on abdominal segment 8 19

19a(18b) a. Dorsal opening of thoracic spiracle directed transversely to axis of pupa Athericidae, Atherix Meigen
19b a. Dorsal opening of thoracic spiracle circular, generally on short or moderately long tubercle 20

20a(19b) a. Thorax with anterior transverse row of dark colored pits b. Dorsal opening of thoracic spiracle at end of short tubercle Pelecorhychidae
20b a. Thorax without anterior transverse row of dark colored pits. Dorsal opening of thoracic spiracle circular, at end of short or moderately long tubercle Empididae [in part]

21a(1b) a. Pupa enclosed in unmodified last larval skin b. Head capsule distinct Stratiomyidae
21b a. Pupa enclosed in last larval skin that is modified to form a puparium b. No head capsule also: Pupa shape variable Cyclorrhaphous-Brachycera: Ephydridae, Muscidae, Phoridae, Sarcophagidae, Fletcherimyia fletcheri (Aldrich, 1916), Scathophagidae, Sciomyziidae, Syrphidae

Mature Larvae
(adapted from Courtney and Merritt 2008)

1a a. Mandibles moving against one another in a horizontal or oblique plane b. Head capsule usually complete and fully exposed, except retracted and reduced in Tipulidae Nematocera, 2
1b a. Mandibles or mouth hooks moving parallel to one another in a vertical plane b. Head capsule variously reduced posteriorly, partially or almost completely retracted within thorax even if such retracted portions comprise only a few slender rods Brachycera, 15

Nematocera

2a(1a) a. Head capsule partially to fully retracted within thorax, usually with longitudinal incisions of varying depths dorsolaterally, in extreme cases head consisting only of several slender rods b. Respiratory system metapneustic or apneustic, posterior spiracles usually bordered by 1-3 or 5-7 pairs of short lobes that are often fringed with short to very long hairs Tipuloidea
2b a. Head capsule complete, usually without longitudinal incisions dorsolaterally, completely exserted b. Respiratory system amphipneustic, metapneustic, or apneustic c. Posterior spiracles usually without bordering fringed lobes 3

3a(2b) a. Head not distinctly separated from thorax b. Body divided into 6 major divisions, the 1st comprising the fused head, thorax, and Ab1 b. Each division with a median suctorial disc ventrally Blephariceridae, Blepharicera Macquartt
3b a. Head showing a distinct constrictive separation from the thorax b. Suctorial discs absent 4

4a(3b) a. Abdomen terminating in a slender, respiratory siphon that when fully exserted is nearly as long as the body 5
4b a. Not as above 6

5a(4a) a. Respiratory siphon retractile b. Anal papillae comprised of two small, simple lobes c. Body segments with multiple transverse ridges, rows of small setae, or setiferous (setae-bearing) papillae (soft projections) d. Ab1-3 with a pair of ventral prolegs, sometimes very small, bearing a single, slender, curved claw Ptychopteridae
5b a. Respiratory siphon nonretractile b. Anal papillae comprised of two large, pinnately branched lobes c. Body segments smooth, shiny, white d. Abdominal segments without prolegs Axymyiidae, Axymyia furcata McAtee 1921

6a(4b) a. Thoracic segments fused and indistinctly differentiated, forming a single segment that is wider than any of abdominal segments b. Thoracic and abdominal segments with prominent, lateral fanlike tufts of long setae, and/or anal division with a setal fan 7
6b a. Thoracic segments usually individually distinguishable b. Thorax and abdomen about equal in diameter or abdomen wider, setae on thoracic and abdominal segments not tufted and anal division without setal fan 9

7a(6a) a. Antennae not prehensile and with only short apical setae b. Prominent mouth brushes present on either side of labrum Culicidae
7b a. Antennae prehensile (grasping), with long apical setae b. Mouth brushes absent 8

8a(7b) a. Antennae inserted close together b. A transverse row of spiniform setae on each side of head c. Anal division with a tuft oflong setae ventrally instead of a fan Corethrellidae, Corethrella Coquillett
8b a. Antennae inserted far apart b. Head without a transverse row of setae laterally c. Anal division with longitudinal fanlike row of setae Chaoboridae

9a(6b) a. Paired crochet-bearing prolegs ventrally on Ab1 and usually Ab2 b. Anal division with 2 flattened dorsolateral postspiracular lobes having setose (hair-covered) margins projecting above a conical, dorsally sclerotized segment bearing the terminal anus and anal papillae Dixidae
9b a. Abdominal segments without prolegs, except on anal division b. Anal division without flattened, fringed postspiracular lobes and a conical, dorsally sclerotized anal division 10

10a(9b) a. Prothorax with 1 proleg or a pair of prolegs ventrally 11
10b a. Prothorax lacking prolegs 14

11a(10a) a. Head capsule usually with a pair of conspicuous, folding labral fans dorsolaterally b. Ab5-8 swollen, posterior segment terminating in a ring or circlet of numerous radiating rows of minute hooks Simuliidae
11b a. Head capsule lacking labral fans b. Posterior abdominal segments not conspicuously swollen nor with radiating rows of hooks terminally, although anal proleg(s) bearing crochets may be present 12

12a(11b) a. Respiratory system amphipneustic b. Anterior spiracles on short stalks, and posterior spiracles opening into a transverse cleft between fingerlike processes on Ab8 c. Prothoracic and anal prolegs unpaired Thaumaleidae, Androprosopa Mik
12b a. Respiratory system apneustic b. Apneustic, spiracles not present c. Prothoracic or anal prolegs usually paired even if distinction is only a slight separation of the apical spines 13

13a(12b) a. All body segments dorsally with prominent tubercles, elevated fleshy processes and/or setae Ceratopogonidae[in part]
13b a. Body segments lacking prominent dorsal tubercles and setae Chironomidae

14a(10b) a. All body segments secondarily divided into 2-3 subdivisions with some or all of these subdivisions bearing dorsal sclerotized plates b. Remainder of integument with numerous dark spots that together with the dorsal plates impart a grayish brown coloration to larva c. Respiratory system amphipneustic, posterior spiracles usually at apex of a relatively short, conical respiratory tube Psychodidae
14b a. Body segments usually not secondarily divided b. Intugement smooth, shiny, and creamy white, lacking all surface features except a few setae that may be noticeable at tip of anal division c. Respiratory system apneustic, no spiracles, anal proleg sometimes retractible bearing a few crochets (curved hooks) Ceratopogonidae

Brachycera

15a(1b) a. Sclerotized portions of head capsule exposed externally although sometimes greatly reduced, in which case slender tentorial and metacephalic rods prominent internally Orthorrhaphous-Brachycera, 16
15b a. External sclerotized portions of head capsule absent, head reduced to an internal cephalopharyngeal skeleton of rather characteristic form Cyclorrhaphous-Brachycera, 21

16a(15a) a. Body somewhat depressed b. Integument toughened and leathery from calcium deposits that are evident as numerous small reticulately arranged facets c. Head capsule capable of only slight independent movement, usually with distinctive lateral eye prominences Stratiomyidae
16b a. Larva usually not conspicuously depressed b. Integument not toughened or bearing a network of facets c. Head capsule capable of extensive independent movement, but without distinctive eye prominences 17

17a(16b) a. Head capsule well developed dorsally, closed ventrally by a submental plate b. Tentorial rods solidly fused with head capsule internally c. A brush of backwardly curved bristles usually present on each side of clypeus above and near base of each mandible 18
17b a. Head capsule reduced to a pair of slender metacephalic rods b. They and tentorial rods flexibly articulate with anterior cephalic sclerites c. Submental plate and brushes of bristles above mandibles absent 20

18a(17a) a. Posterior spiracles present, opening within slits on either side of a vertically linear stigmatal bar or a retractile, laterally compressed spine b. Body integument with longitudinal striations, except in some species where integument totally covered by short, velvety pubescence c. Ab1-7 girdled by 3 or 4 pairs of fleshy creeping welts (setae-bearing swellings) or prolegs, these being the only projections from the segments Tabanidae
18b a. Posterior spiracles greatly reduced or situated within a small terminal cavity b. Integument without striations or extensive covering of pubescence c. Prolegs, if present, limited to 1-2 ventral pairs on each abdominal segment 19

19(18b) a. Larva cylindrical, with smooth shiny integument and with segmentation beadlike b. Lacking tubercles and prolegs Pelecorhychidae, Glutops Burgess
19b a. Larvae with slender lateral and dorsolateral tubercles on abdominal segments increasing in length posteriorly b. Abdominal segments with ventral prolegs bearing crochets also: Two longer tubercles, fringed with hairs, on anal division c. Ab1-7 each with pair of short, broad pro legs, shorter than half width of body Athericidae, Atherix Meigen

20a(19b) a. Larva metapneustic b. Posterior spiracles situated at the base of upper 2 of 4 smooth primary lobes of anal division c. Transverse ventral creeping welts present on abdominal segments c. Metacephalic rods expanded posteriorly Dolichipodidae
20b a. Larva usually apneustic b. Anal division with 1-4 rounded lobes bearing apical setae c. Abdominal segments bearing paired prolegs with apical crochets also: if metapneustic, then anal division with only a single lobe below spiracles, and abdominal segments with ventral creeping
welts; metacephalic rods slender posteriorly Empididae

21a(15b) a. Posterior spiracular plates fused or very closely approximated, usually on apex of a telescopic respiratory tube also: Prothoracic spiracles, if present, with stigmatal openings near apex of a simple stalk; cephalopharyngeal skeleton lacking mouth hooks in aquatic larvae of family, a ribbed filter chamber in area normally occupied by mouth hooks Syrphidae
21b a. Posterior spiracular plates always distinctly separated whether mounted on a telescopic respiratory tube or not 22

22a(21b) a. Anterior spiracles simple, each with l to several openings arranged peripherally at apex of short projection b. Body often dorsoventrally flattened and bearing a series of spicules or tubercles c. Posterior spiracles with openings arranged in 2 pairs placed one behind the other Phoridae
22b a. Anterior spiracles either absent or bearing 2 or more short or branched papillae b. Posterior spiracles with openings usually arranged in parallel or in radiating pattern 23

23a(22b) a. Cephalopharyngeal skeleton with a sclerotized ventral arch below base of mouth hooks, its anterior margin usually toothed b. Body segments often extensively covered with short, fine hairs, and anal division often somewhat tapered, its apex with tubercles surrounding posterior spiracles that are only slightly elevated Sciomyziidae
23b a. Cephalopharyngeal skeleton lacking a ventral arch b. If body extensively covered with short, fine hairs then a respiratory siphon present, or each spiracle situated on a short tubular projection on anal division 24

24a(23b) a. Spiracular slits inclined more-or-less vertically b. Inhabitants of pitcher plants Sarcophagidae, Fletcherimyia fletcheri (Aldrich, 1916)
24b a. One or more of the spiracular slits nearly horizontal 25

25a(24b) a. Anal division somewhat tapered, usually ending in an elongate retractile respiratory tube that lacks dorsal tubercles b. Integument of posterior abdominal segments covered with setae or spinules, or with setaceous (setae-bearing) tubercles on some segments Ephydridae
25b a. Anal division rather truncate (cut off squarely), either with short respiratory tube or basally fused conical spiracular prominences, each bearing a dorsal tubercle b. Integument with setae only on intersegmental areas, setaceous tubercles, if present, restricted to anal division 26

26a(25b) a. Posterior spiracular plate with one or more bordering lobes or spines, or with a sharp ridge along dorsal margin also: Posterior spiracular openings radiating from ecdysial scar at distinctly less than right angles, or irregularly arranged; prothoracic spiracle a cribriform (sievelike) plate, or with many (> 10) papillae arranged in a bicornuate (two-homed) fan Scathophagidae
26b a. Posterior spiracular plate without lobes, spines, or ridges along margins also: Cephalopharyngeal skeleton with accessory oral sclerite below mouth hooks Muscidae

References

Borkent A. 2012. The Pupae of Culicomorpha - morphology and a new phylogenetic tree. Zootaxa 3396: 1-98.
Courtney GW, Merritt RW. 2008. Chapter 22. Aquatic Diptera. Part One. Larvae of aquatic Diptera, pp. 687-722 in Merritt RW, Cummins KW, Berg MB, eds. 2008. An Introduction to the Aquatic Insects of North America. 4th Ed., Kendall/Hunt Publishing Co., Dubuque, Iowa, USA.
Merritt RW, Webb DW. 2008. Chapter 22. Aquatic Diptera. Part Two. Pupae and adults of aquatic Diptera, pp. 723-771 in Merritt RW, Cummins KW, Berg MB, eds. 2008. An Introduction to the Aquatic Insects of North America. 4th Ed., Kendall/Hunt Publishing Co., Dubuque, Iowa, USA.

Updates

• November 29, 2013 - genera and species-level keys are available for the Michigan family:
  • Simuliidae (black flies)

• November 27, 2013 - genera and species-level keys are available for the Michigan family:
  • Culicidae

• November 25, 2013 - generic keys are available for the Michigan families:
  • Chaoboridae
  • Dixidae
  • Ptychopteridae
  • Stratiomyidae

Page created: April 11, 2006; Last updated: December 10, 2013(EB)