vvEPA
United States
Environmental Protection
Agency
Taxonomic Aids for
Mid-Atlantic Benthic
Macro! nvertebrates
Ephemeroptera: Baetidae
Plecoptera: Capniidae/Leuctridae
Diptera: Simuliidae
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EPA-260-R-08-014
November 2008
Taxonomic Aids for
Mid-Atlantic Benthic
Macro! nvertebrates
Ephemeroptera: Baetidae
Plecoptera: Capniidae/Leuctridae
Diptera: Simuliidae
Prepared by:
John Pfeiffer, Ely Kosnicki, Michael Bilger, Brett Marshall1 and Wayne Davis2
1 EcoAnalysts, Inc.
1420S. Elaine St., Suite 14
Moscow, ID 83843
2 U.S. Environmental Protection Agency
Office of Environmental Information
Office of Information Analysis and Access
Environmental Analysis Division
Washington, DC 20460
U.S. Environmental Protection Agency
Office of Environmental Information
Office of Information Analysis and Access
Washington, DC 20460
Printed on chlorine free 100% recycled paper with
100% post-consumer fiber using vegetable-based ink.
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Taxonomic Aids for Mid-Atlantic Benthic Macroinvertebrates
Notice
This document has been reviewed and approved in accordance with U.S.
Environmental Protection Agency policy. Mention of trade names, products, or
services does not convey and should not be interpreted as conveying official EPA
approval, endorsement, or recommendation for use.
Funding was provided by USERA under U.S. Department of Commerce, Commerce
Information Technology Solutions Contract No. 50-CMAA-900065 with Perot
Systems Government Services, Inc. and under Contract 68-C-04-006 with Great
Lakes Environmental Center, Inc.
Suggested citation:
Pfeiffer, J., Kosnicki, E., Bilger, M., Marshall, B.D. and W. Davis. 2008. Taxonomic
Aids for Mid-Atlantic Benthic Macroinvertebrates. EPA-260-R-08-014. United
States Environmental Protection Agency, Office of Environmental Information,
Environmental Analysis Division, Washington, DC.
The entire document can be downloaded from:
http://www.epa.gov/bioindicators/html/publications.html
USEPA Contact:
Wayne Davis at davis.wayne@epa.gov
Acknowledgements
The authors gratefully acknowledge the contribution and reviews by A.J. Smith, Larry
Abele, Diana Heitzman, Brian Duffy, Mike Bolton, Greg Pond, Evan Hornig and Keith
VanNess.
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Taxonomic Aids for Mid-Atlantic Benthic Macroinvertebrates
Contents
Notice v
Acknowledgements v
Figures vii
Introduction x
Ephemeroptera: Baetidae A-1
Plecoptera: Separation of Leuctridae and Capniidae B-1
Diptera: Simuliidae C-1
Literature Cited D-1
VI
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Taxonomic Aids for Mid-Atlantic Benthic Macroinvertebrates
Figures
Figure A-1. Median caudal filament reduced (Heterocloeon sp.) A-1
Figure A-2. Median caudal filament developed (Baetis sp.) A-1
Figure A-3. Caudal filaments are often damaged, particularly in bioassessment samples A-1
Figure A-4. Hair fringe on the dorsal surface of the femur, tibia and tarsi A-2
Figure A-5. Lateral view of the thorax of Acentrella sp A-2
Figure A-6. Lateral view of P/aud/fus sp. thorax A-3
Figure A-7. Tarsal claw of Heterocloeon sp A-3
Figure A-8. Procoxal gills of Heterocloeon sp A-3
Figure A-9. Lateral view of thorax of Heterocloeon sp A-3
Figure A-10. Labial palps truncate, ventral view. (Centroptilum sp.) A-4
Figure A-11. Labial palps more elongate, sometimes resembling mittens. (Heterocloeon sp.) A-4
Figure A-12. Labrum with deep notch. (Pseudocentroptiloides sp.) A-5
Figure A-13. Labial palps and labium of Pseudocentroptiloides sp A-5
Figure A-14. Notched labrum. (Centroptilum sp.) A-5
Figure A-15. The glossae and paraglossae are often hidden behind the
labial palps. (Centroptilum sp.) A-5
Figure A-16. Incisor region of right mandible (lower right) separated nearly
to the base. (Centroptilum sp.) A-6
Figure A-17. Maxillary palp of Centroptilum sp A-6
Figure A-18. Incisor regions of mandible separated less than halfway to base.
(Procloeon sp.) A-6
Figure A-19. Maxillary palp of Procloeon sp A-6
Figure A-20. Compound gills present. (Callibaetis sp.) A-7
Figure A-21. One simple gill arising from the posterior margin of most abdominal
segments. (Baetis sp.) A-7
Figure A-22. Oblique angle of labial palps. (Cloeonsp.) A-8
Figure A-23. Labial palps not truncate and appearing 2-segmented. (Callibaetis sp.) A-8
Figure A-24. Long tarsal claws lack denticles even at high magnification.
(400x, Apobaetis sp.) A-9
Figure A-25. Short tarsal claws. Denticles present. (Baetis sp.) A-9
Figure A-26. Labrum of Apobaetis sp. (400x) A-9
Figure A-27. Labial palp. (Paracloeodes sp.) A-9
Figure A-28. Maxillary palp with excavation prior to apex. (Pseudocloeon sp.) A-10
Figure A-29. The scape is the first apparent segment of an insect antenna.
(Pseudocloeon sp.) A-10
Figure A-30. Labial palp with large, developed medial process. (Pseudocloeon sp.) A-10
Figure A-31. Antennae are inserted close together forming a raised keel between.
(Acerpenna sp.) A-11
Figure A-32. Antennae inserted apart. (Baetis sp.) A-11
VII
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Taxonomic Aids for Mid-Atlantic Benthic Macroinvertebrates
Figures (con't)
Figure A-33. Gills on abdominal segment 7 are longer and narrower (arrow) than
those on preceding segments. (Acerpenna sp.) A-12
Figure A-34. Dorsal view. (Acerpenna sp.) A-12
Figure A-35. Lateral view of Diphetor hageni A-12
Figure A-36. Ventral view. (Diphetor hageni) A-12
Figure A-37. Baetissp. larvae A-13
Figure A-38. Acentrella turbida in dorsal view A-14
Figure A-39. Lateral margin of the thorax of a late instar Acentrella larva showing the
hind wing pad reduced to a small, downward pointing "scale" A-14
Figure A-40. Two late instar Acentrella turbida larvae A-14
Figure A-41. Dorsal view of Acentrella parvulum A-14
Figure A-42. Plauditussp. in dorsal view A-15
Figure A-43. Another Plauditussp. in dorsal view A-15
Figure A-44. Dorsal view of Heterocloeon sp A-16
Figure A-45. Heterocloeon amplum, one of the species formerly in the genus Acentrella sp A-16
Figure A-46. The simplest diagnostic character for Heterocloeon sp., when present,
is the occurrence of simple gills arising from the base of the procoxae (arrows) A-16
Figure A-47. Heterocloeon sp. larvae sometimes have a heavily scleritized ridge in addition
to a row of denticles on thetarsal claw A-16
Figure A-48. Dorsal view of the abdomen of Pseudocentroptiloides sp A-17
Figure A-49. The deeply cleft labrum of Pseudocentroptiloides sp A-17
Figure A-50. Dorsal view of Centroptilum sp A-18
Figure A-51. Dorsal view of Procloeonsp A-18
Figure A-52. The banding on the caudal filaments of Centroptilum sp. and Procloeon sp A-18
Figure A-53. Dorsal view of Cloeonsp A-19
Figure A-54. Close-up of the compound gills of Cloeonsp A-19
Figure A-55. Dorsal view of Callibaetis sp A-20
Figure A-56. Ventral view of the head of Callibaetis sp A-20
Figure A-57. Ventral view of the palps of Callibaetis sp A-20
Figure A-58. Dorsal view of Apobaetissp A-21
Figure A-59. Dorsal view of Paracloeodes sp A-21
Figure A-60. Dorsal view of Pseudocloeon sp A-22
Figure A-61. Ventral view of the head of Pseudocloeon sp A-22
Figure A-62. Dorsal view of Acerpenna pygmaea A-23
Figure A-63. Gill 7 of Acerpenna pygmaea A-23
VIM
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Taxonomic Aids for Mid-Atlantic Benthic Macroinvertebrates
Figures (con't)
Figure A-64. Dorsal and lateral views of Diphetor hageni. A-24
Figure A-65. The reduced, bifid prostheca on the right mandible of Diphetor hageni A-24
Figure A-66. Baetis intercalaris, a common species in the mid-Atlantic A-25
Figure A-67. The labial palps of Baetis tricaudatus A-25
Figure B-1. Ventral view of the abdominal segments of Allocapnia sp. (Capniidae) B-1
Figure B-2. Ventral view of the abdomen of Leuctra sp. (Leuctridae) B-1
Figure B-3. Dorsal view of Leuctridae (top) and Capniidae (bottom) abdomens B-2
Figure B-4. Dorsal view of a late instar Capniidae larva thorax (Allocapnia sp.) B-2
Figure B-5. Dorsal view of a late instar Leuctridae larva thorax (Leuctra sp.) B-2
Figure C-1. Head lacking labral fans (Twinniasp.) C-1
Figure C-2. Anal sclerite "Y" shaped. Dorsal view of end of abdomen of Twinnia sp C-1
Figure C-3. Head with labral fans present (Simulium sp.) C-1
Figure C-4. Anal sclerite "X" shaped. Compound anal gills are visible just to the left of
the sclerite (Simulium sp.) C-1
Figure C-5. Dorsum of Prosimulium sp. head C-2
Figure C-6. Ventral view of Prosimulium sp. head C-2
Figure C-7. Antenna of Prosimulium sp C-2
Figure C-8. Dorsum of Grenierasp. head C-2
Figure C-9. Lateral view of Stegopterna sp. abdomen C-3
Figure C-10. Hypostomal teeth of Stegopterna sp C-3
Figure C-11. Ventral view of the posterior of Greniera sp C-3
Figure C-12. Ventral view of Simuliumsp. head C-4
Figure C-13. Compound anal gills, present in some species of Simulium sp C-4
Figure C-14. Anal gills consisting of three simple lobes (Cnephia sp.) C-4
Figure C-15. Posterior of Cnephia sp. abdomen C-5
Figure C-16. Venter of the head of Cnephia sp C-5
Figure C-17. Posterior of Greniera sp. abdomen C-5
Figure C-18. Lateral view of Grenierasp C-6
Figure C-19. Ventral view of Grenierasp. head C-6
IX
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Taxonomic Aids for Mid-Atlantic Benthic Macroinvertebrates
Introduction
As the use of biological monitoring becomes more prevalent, biological monitoring
data are being collected by a variety of state, federal, tribal and local governments
as well as watershed groups, conservation districts, and volunteer organizations.
To ensure that the maximum benefits are realized from these data, it is important
to maintain consistency in the collection, identification, analysis, and reporting of
biological data. One difficulty in using benthic macroinvertebrates as indicators
of stream water quality has been that some taxonomic groups have undergone
frequent and extensive systematic revision, making data consistency problematic.
One of the groups commonly encountered that has recently undergone revision
is the mayfly (Ephemeroptera) family Baetidae. The genera covered in this
key include: Acentrella, Acerpenna, Apobaetis, Baetis, Barbaetis, Callibaetis,
Centroptilum, Cloeon, Diphetor, Heterocloeon, Paracloeodes, Plauditus, Procloeon,
Pseudocentroptiloides, and Pseudocloeon. The key to genera of the family Baetidae
is based on keys in Merritt and Cummins (1996) and Lugo-Ortiz and McCafferty
(1998). The distributional data is based on Randolph (2002).
Larvae of the black fly (Diptera) family Simuliidae have proven to be among the
more difficult macroinvertebrate groups to identify to the generic level. The following
genera are covered in the key: Cnephia, Ectemnia, Greniera, Prosimulium/Helodon,
Simulium, Stegopterna, and Twinnia. The key to the genera of Simuliidae is based on
the genus key by Adler, et al. (2004).
Finally, separation of larvae of the stonefly (Plecoptera) families Leuctridae and
Capniidae can be difficult, especially in early instars. The most reliable character to
separate the two taxa, the membranous pleural fold on the venter of the abdomen,
is often difficult to see in preserved specimens. The key to distinguishing these two
genera is based on Stewart and Stark, 2002.
The purpose of this document is to help improve accuracy and consistency of
taxonomist identifications in the mid-Atlantic Region by providing the most recent
information available and by clarifying difficult couplings with photographs. The
following keys are designed to be used in the mid-Atlantic region, covering the
states of Delaware, District of Columbia, Maryland, Pennsylvania, Virginia, and West
Virginia. Several taxa not documented from these states but occurring in adjacent
regions have been included.
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Taxonomic Aids for Mid-Atlantic Benthic Macroinvertebrates
Ephemeroptera: Baetidae
1. Median caudal filament reduced, approximately 1/10 or less length of cerci (Fig. A-1) 2
1'. Median caudal filament longer, usually 1/2 to sub-equal in length to cerci (Figs. A-2 and A-3) 4
Figure A-1. Median caudal filament reduced
(Heterocloeon sp.).
Figure A-2. Median caudal filament developed
(Baef/ssp.).
Figure A-3. Caudal filaments are often damaged,
particularly in bioassessment samples. Look for
broken filaments. If the broken median filament is
approximately the same diameter as the cerci, its
length was likely to have been sub-equal or greater in
length than that of the cerci.
Ephemeroptera: Baetidae
A-1
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Taxonomic Aids for Mid-Atlantic Benthic Macroinvertebrates
2. (1) Usually with a row of fine setae on dorsal margin of femur, tibia, and tarsus (Fig. A-4); hind wing pads
reduced to a small "scale" (Fig. A-5) Acentrella
2'. Tibia and tarsus without dorsal row of fine setae, although dorsal setal row often present on femur; hind
wing pads absent or reduced, but not as above 3
Figure A-4. Hair fringe on the dorsal surface of the
femur, tibia and tarsi. The hair fringe is apparent on all
legs, but may be worn or broken on older specimens.
(Acentrella sp.)
Figure A-5. Lateral view of the thorax of Acentrella sp.
Hind wing pads reduced to a small, downward-pointing
"scale". This can be difficult to discern, particularly in
immature specimens.
A-2
Ephemeroptera: Baetidae
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Taxonomic Aids for Mid-Atlantic Benthic Macroinvertebrates
3. (2') Claws with a single row of denticles; hind wing pads absent and posterior lateral
margin of metanotum approximating a right angle in lateral view (Fig. A-6); procoxal gills
never present Plauditus
3'. Claws with two rows of denticles or one row of denticles and a parallel ridge in place of second
row (Fig. A-7). (Note that magnification of 400X is usually required to see these characters);
some species with simple gills on procoxa (Fig. A-8); hind wing pads reduced but present
(Fig. A-9) Heterocloeon
Figure A-6. Lateral view of Plauditus sp. thorax.
Posterior lateral margin of metanotum (arrow) visible
under front wing pad forming a right angle. Even in late
instar larvae such as this, no trace of a hind wing pad is
present. Compare to Figures A-5 and A-9.
Figure A-7. Tarsal claw of Heterocloeon sp. In this
species, there is one row of denticles with a ridge in the
place of the second row of denticles (400x).
Figure A-8. Procoxal gills of Heterocloeon sp. The
simple gill on the procoxa usually sticks out away
from the body and can best be seen against a dark
background.
Figure A-9. Lateral view of thorax of Heterocloeon sp.
Hind wing pads are reduced but visible (arrow).
Ephemeroptera: Baetidae
A-3
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Taxonomic Aids for Mid-Atlantic Benthic Macroinvertebrates
4. (1') Apex of labial palps simple and truncate (Fig. A-10); caudal filaments with distinct banding every
3rd or 5th segment 5
4'. Labial palps variable but never truncate as above (Fig. A-11); caudal filaments not banded every
3rd or 5th segment 7
Figure A-10. Labial palps truncate, ventral view.
(Centroptilum sp.)
Figure A-11. Labial palps more elongate, sometimes
resembling mittens. (Heterocloeon sp.)
A-4
Ephemeroptera: Baetidae
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Taxonomic Aids for Mid-Atlantic Benthic Macroinvertebrates
5. (4) Labrum w/deep triangular median notch on anterior margin (Fig. A-12); Labial palps
broadly truncate and paraglossae broad and longer than glossae (Fig. A-13); claws longer
than respective tarsi; gills simple (not known from states included in this key, but found in
adjacent states (OH) Pseudocentroptiloides
5'. Labrum with smaller, squared median notch along anterior margin (Fig. A-14); paraglossae sub-equal to
glossae (Fig. A-15); claws usually shorter than respective tarsi; gills simple or compound 6
Figure A-12. Labrum with deep notch.
(Pseudocentroptiloides sp.)
Figure A-13. Labial palps and labium of
Pseudocentroptiloides sp.
ase of glossae
and paraglossae
Figure A-14. Notched labrum. The "smaller" notch is
clearly visible using a dissecting scope. (Centroptilum
sp.)
Figure A-15. The glossae and paraglossae are often
hidden behind the labial palps. However, you should
be able to discern them without removing the palps.
All that is necessary to determine is whether they
are about the same length, or the outer structures
(paraglossae) are much longer. (Centroptilum sp.)
Ephemeroptera: Baetidae
A-5
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Taxonomic Aids for Mid-Atlantic Benthic Macroinvertebrates
6. (5') Incisor of mandible usually separated to base (Fig. A-16); maxillary palps 3-segmented with segment
3 as long or longer than segment 2 (Fig. A-17); gills simple; cerci with lateral setae absent in distal fourth;
abdomen with lateral spines absent or reduced Centroptilum
6'. Incisor of mandible usually separated less than half the distance to base (Fig. A-18); maxillary palps 2 or
3-segmented with segment 3 shorter than segment 2 when present (Fig. A-19); gills usually compound;
cerci with lateral setae usually present to tip; abdomen with lateral spines well developed on at least
segments 8 and 9 Procloeon
Figure A-16. Incisor region of right mandible (lower
right) separated nearly to the base. This character
can usually be seen by pushing down on the head to
spread the mouthparts. (Centroptilum sp.)
Figure A-17. Maxillary palp of Centroptilum sp. The
second and third segments of the maxillary palp are
about equal in length.
Figure A-18. Incisor regions of mandible separated less
than halfway to base. (Procloeon sp.)
Figure A-19. Maxillary palp of Procloeon sp. The third
(apical) segment is much shorter than the second.
A-6
Ephemeroptera: Baetidae
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Taxonomic Aids for Mid-Atlantic Benthic Macroinvertebrates
7. (4') Compound gills present (Fig. A-20) (Cloeon, Callibaetis) 8
7'. All gills simple (Fig. A-21) 9
Figure A-20. Compound gills present.
These often appear as two separate
gills arising from the same base near
the posterior margin of each abdominal
segment. (Callibaetis sp.)
Figure A-21. Simple gills. One simple gill arising from
the posterior margin of most abdominal segments.
(Baetis sp.)
Ephemeroptera:Baetidae
A-7
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Taxonomic Aids for Mid-Atlantic Benthic Macroinvertebrates
8. (7) Labial palps 3-segmented, obliquely truncate (Fig. A-22); hind wing pads absent; recurved flaps on
gills folded dorsally Cloeon
&. Labial palps appearing 2-segmented, long and "spoon-shaped" (Fig. A-23); hind wing pads present;
recurved flaps on gills folded ventrally Callibaetis
»
Oblique Angle formed
by truncate palpi
Photo: S.K. Burian
Figure A-22. Oblique angle of labial palps. Cloeon
is usually found in seasonal wetlands; rare in stream
bioassessment samples. (Cloeon sp.)
Figure A-23. Labial palps not truncate and appearing
2-segmented. This taxon is more common in stream
bioassessment samples but is also collected from
ephemeral habitats. (Callibaetis sp.)
A-8
Ephemeroptera:Baetidae
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Taxonomic Aids for Mid-Atlantic Benthic Macroinvertebrates
9. (7') Claws without denticles and long, equal to or greater than half the length of their respective tarsi
(Fig. A-24) (Apobaetis, Paracloeodes) 10
9'. Claws with denticles and shorter, less than half the length of their respective tarsi (Fig. A-25) 11
Figure A-24. Long tarsal claws lack denticles even at
high magnification. (400x, Apobaetis sp.)
Figure A-25. Short tarsal claws. Denticles present. Total
length less than 50% of tarsus. (Baetis sp.)
10. (9) Claws sub-equal to length of tarsi (Fig. A-24); labrum without median notch on anterior margin (Fig.
A-26) (not recorded from the mid-Atlantic, but found in adjacent states) Apobaetis
10'. Claws about half the length of tarsi; labrum with median notch; labial palps notched as in Fig. A-27. (not
recorded from the mid-Atlantic, but found in adjacent states NY, OH) Paracloeodes
Figure A-26. Labrum of Apobaetis sp. (400x). Unlike
other Baetidae, there is no median notch on the front
margin of the labrum.
Figure A-27. Labial palp. (Paracloeodes sp.)
Ephemeroptera: Baetidae
A-9
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Taxonomic Aids for Mid-Atlantic Benthic Macroinvertebrates
11. (9') Maxillary palps with sub-apical excavation (Fig. A-28); antennal scape with distal lobe (Fig. A-29);
labial palp often with well developed medial process (Fig. A-30) Pseudocloeon
11'. Maxillary palps and scape not as above, medial process may or may not be developed 12
Figure A-28. Maxillary palp with excavation prior to
apex. (Pseudocloeon sp.)
Figure A-29. The scape is the first apparent segment
of an insect antenna. (Pseudocloeon sp.)
Figure A-30. Labial palp with large, developed medial
process. (Pseudocloeon sp.)
A-10
Ephemeroptera: Baetidae
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Taxonomic Aids for Mid-Atlantic Benthic Macroinvertebrates
12. (11') Antennae inserted close together forming a raised keel between insertion points
(Fig.A-31) 13
12'. Antennae inserted apart, area between antenna insertions points not raised (Fig. A-32) 14
Figure A-31. Antennae are inserted close together
forming a raised keel between. (Acerpenna sp.)
Figure A-32. Antennae inserted apart. In these taxa,
the area between the antennae (frons) is relatively
flat and does not form a keel. (Baetis sp.)
Ephemeroptera:Baetidae
A-11
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Taxonomic Aids for Mid-Atlantic Benthic Macroinvertebrates
13. (12) Lateral gills present on abdominal segment 1; gill on abdominal segment 7 pointed and narrower
than preceding gills (Fig. A-33); Labial palp with well developed medial process (similar to Fig. A-30); tuft
of setae on right mandible between incisors and molar region (Fig. A-34) Acerpenna
13'. Gills absent on abdominal segment 1 (Fig. A-35); gill on abdominal segment 7 rounded and similar in
shape to gills on preceding segments; prostheca on right mandible reduced; bifid and serrate on inner
margin (Fig. A-36); generally brown without distinct marking; occasionally light lateral margins on
abdominal segments Diphetor hageni
Figure A-33. Gills on abdominal segment 7 are longer
and narrower (arrow) than those on preceding segments.
(Acerpenna sp.)
Figure A-34. The tuft of setae between the molar region
(right bottom) and the incisors (left bottom) is located
proximal to the incisors best viewed at 400x. Dorsal
view. (Acerpenna sp.)
Figure A-35. Lateral view of Diphetor hageni. On the
first abdominal segment, no gill or gill scar is present on
the posterior lateral margin (black arrow). Even though
the gills on following segments may be missing, a
darkened gill scar is usually visible (yellow arrows).
Figure A-36. In Diphetor, the prostheca is reduced to a
bifid (forked) hair. This species is often misidentified as
Baetis. Ventral view. (Diphetor hageni)
A-12
Ephemeroptera: Baetidae
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Taxonomic Aids for Mid-Atlantic Benthic Macroinvertebrates
14. (12') Antennae long, length greater than twice the length of the head capsule; color variable
(Fig.A-37) Baetis
14'. Antennae short, sub-equal in length to head capsule; color pale with dark pigment bands encircling
some abdominal segments (in the mid-Atlantic, known only from southern Virginia) Barbaetis
Figure A-37. Baetis sp. larvae have long antennae. This is one of the most
commonly collected baetid taxa in North America. (Baetis tricaudatus)
Ephemeroptera: Baetidae
A-13
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Taxonomic Aids for Mid-Atlantic Benthic Macroinvertebrates
Acentrella sp.
The genus Acentrella sp. is a common component of the baetid community in mid-Atlantic
streams. The fringe of fine hairs present on the femur, tibia, and tarsus is the easiest character
to use in distinguishing this genus. In older specimens this fringe may be worn or broken but is
usually still apparent. One species (Acentrella turbida) is recorded from the region. A second
species (Acentrella parvulum), has been recorded from Ohio westward, and may eventually be
found in the mid-Atlantic.
Additional References:
Jacobus, L.M. and W.P. McCafferty. (2006). A new species of Acentrella Bengtsson (Ephemeroptera:
Baetidae) from Great Smoky Mountains National Park, USA: Aquatic Insects, v. 28, p. 101 -111.
McCafferty, W.P., Wigle, M.J. and R.D. Waltz. (1994). Systematics and biology of Acentrella turbida
(McDunnough) (Ephemeroptera:Baetidae). Pan-Pacific Entomologist 70[4], 301-308.
Morihara, O.K. and W.P. McCafferty. (1979). The Baetis Larvae of North America (Ephemeroptera:Baetidae).
Transactions of the American Entomological Society 105, 139-221.
Wiersema, N.A. (2000). A new combination for two North American small Minnow Mayflies (Ephemeroptera:
Baetidae). Entomological News 111[2], 140-142.
Figure A-38.
Acentrella turbida
in dorsal view.
The body form
superficially
resembles that
of Heptageniidae
in many eastern
specimens.
Figure A-39. Lateral margin
of the thorax of a late instar
Acentrella larva showing the
hind wing pad reduced to a
small, downward pointing
"scale".
Figure A-40.
Two late instar
Acentrella turbida
larvae.
Figure A-41. Dorsal view
of Acentrella parvulum.
This species has not been
recorded from the mid-
Atlantic, but has been found
in Ohio.
A-14
Ephemeroptera:Baetidae
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Taxonomic Aids for Mid-Atlantic Benthic Macroinvertebrates
Plauditus sp.
The genus Plauditus sp. was erected in 1998 encompassing species which were previously placed
in the genera Baetis sp. and Barbaetis sp. (Lugo-Ortiz and McCafferty, 1998). Species within the
genus have a reduced median caudal filament and lack a hind wing pad. They are generally small,
rather fragile baetids. Plauditus sp. is common in stream bioassessment samples from the mid-
Atlantic.
Additional References:
Lugo-Ortiz, C.R. and W.P. McCafferty. (1998). A new North American genus of Baetidae (Ephemeroptera)
and key to Baetis complex genera. Entomological News 109[5], 345-353.
Morihara, O.K. and W.P. McCafferty. (1979). The Baetis Larvae of North America (Ephemeroptera:Baetidae).
Transactions of the American Entomological Society 105, 139-221.
Figure A-43. Another Plauditus sp. in dorsal view.
Figure A-42. Plauditus sp. in dorsal view. The wing
pads are dark because this specimen was about
to emerge when collected. The body is shaped
fundamentally different from most Acentrella sp.
Ephemeroptera:Baetidae
A-15
-------
Taxonomic Aids for Mid-Atlantic Benthic Macroinvertebrates
Heterocloeon sp.
The genus Heterocloeon sp. was recently revised by McCafferty et al. (2005). Several species
formerly included in the genera Acentrella sp. and Plauditus sp. were moved into Heterocloeon
sp. Therefore, many of the species recently moved into Heterocloeon will not key correctly in older
keys.
Additional References:
McCafferty, W.P., Waltz, R.D., Webb, J.M. and L.M. Jacobus. (2005). Revision of Heterocloeon
McDunnough (Ephemeroptera:Baetidae). Journal of Insect Science, v. 5. lnsectscience.org/5.35
Morihara, O.K. and W.R McCafferty. (1979). The Baetis Larvae of North America (Ephemeroptera:Baetidae).
Transactions of the American Entomological Society 105, 139-221.
Muller-Liebenau, I. (1974). Rheobaetis, a New Genus from Georgia (Ephemeroptera:Baetidae). Annals of
the Entomological Society of America 67:555-567.
^m ••^•^^•^^H ^H
Figure A-44. Dorsal view of Heterocloeon sp.
Figure A-45. Heterocloeon amplum, one of the
species formerly in the genus Acentrella sp.
Figure A-46. The simplest diagnostic character for
Heterocloeon sp., when present, is the occurrence
of simple gills arising from the base of the procoxae
(arrows). This can usually be observed without high
magnification. They are more durable than abdominal
gills and are usually attached to even severely
damaged specimens. However, they can be very
difficult to see in rotting or digested specimens.
Figure A-47. Heterocloeon sp. larvae sometimes
have a heavily scleritized ridge in addition to a row of
denticles on the tarsal claw. In this image the ridge
occurs in the foreground and the denticles arise
behind the ridge in the background. This feature occurs
in taxa that may not exhibit procoxal gills.
A-16
Ephemeroptera:Baetidae
-------
Taxonomic Aids for Mid-Atlantic Benthic Macroinvertebrates
Pseudocentroptiloides sp.
The genus Pseudocentroptilodes sp. has not been recorded from the states comprising the mid-
Atlantic, but occurs in Ohio.
Additional References:
Waltz, R.D. and W.P. McCafferty. (1989). New species, redescriptions, and cladistics of the genus
Pseudocentroptiloides (Ephemeroptera:Baetidae). Journal of the New York Entomological Society 97[2],
151-158.
Figure A-48. Dorsal view of the abdomen of
Pseudocentroptiloides sp.
Figure A-49. The deeply cleft labrum of
Pseudocentroptiloides sp.
Ephemeroptera:Baetidae
A-17
-------
Taxonomic Aids for Mid-Atlantic Benthic Macroinvertebrates
Centroptilum sp./Procloeon sp.
Both Centroptilum sp. and Procloeon sp. are found throughout the mid-Atlantic. Both genera have
truncate labial palps and tails banded every 3rd to 5th segment.
Additional References:
Lowen, R.G. and J.F. Flannagan. (1991). Four Manitoba species of Centroptilum Eaton (Ephemeroptera):
Baetidae) with remarks on the genus. Pages 189-205 in Overview and Strategies of Ephemeroptera
and Plecoptera, J. Alba-Tercedor and A. Sanchez-Ortega, eds.The Sandhill Crane Press, Inc.
Gainesville, Florida, USA.
Lowen, R.G. and J.F. Flannagan. (1992). Nymphs and imagoes of four North American species of
Procloeon Bengtsson with description of a new species (Ephemeroptera:Baetidae). The Canadian
Entomologist 124:97-108.
Wiersema, N.A. (1999). Two new species of Procloeon (Ephemeroptera:Baetidae) from Texas.
Entomological News 110(1):27-35.
Figure A-50. Dorsal view of Centroptilum sp.
Figure A-51. Dorsal view of Procloeon sp.
Figure A-52. The banding on the caudal filaments of
Centroptilum sp. and Procloeon sp. are often visible even
if the majority of the cerci are missing.
A-18
Ephemeroptera:Baetidae
-------
Taxonomic Aids for Mid-Atlantic Benthic Macroinvertebrates
Cloeon dipterum
The genus Cloeon sp. consists of one species in North America, Cloeon dipterum. This taxon
occurs in permanent and temporal pools and other small, quiet water bodies, and therefore is
rarely collected in bioassessment samples.
Figure A-53. Dorsal view of Cloeon sp.
Figure A-54. Close-up of the compound gills of
Cloeon sp.
Ephemeroptera:Baetidae
A-19
-------
Taxonomic Aids for Mid-Atlantic Benthic Macroinvertebrates
Callibaetis sp.
Callibaetis sp. is primarily a mayfly of lentic habitats, but will often occur in bioassessment samples
from pools or slow streams. The large, "spoon-shaped" palps are distinctive among North America
Baetidae.
Additional References:
Check, G.R. (1982). A revision of the North American species of Callibaetis (Ephemeroptera:Baetidae) PhD
Dissertation, University of Minnesota.
Figure A-55. Dorsal view of Callibaetis sp.
Figure A-56. Ventral view of the head of Callibaetis sp.
Figure A-57. Ventral view of the palps of Callibaetis sp.
A-20
Ephemeroptera:Baetidae
-------
Taxonomic Aids for Mid-Atlantic Benthic Macroinvertebrates
Apobaetis sp./Paracloeodes sp.
Neither of these genera have been recorded from the states comprising region 3, but have been
found in adjacent states and may eventually be encountered in the Region.
Additional References:
McCafferty, W.P. and D.R. Lenat. (2003). A new Nearctic Paracloeodes (Ephemeroptera:Baetidae).
Entomological News 114:33-36.
McCafferty, W.P. (2000). A new Nearctic species of Apobaetis (Ephemeroptera:Baetidae). Entomological
News, 111:265-269.
Figure A-58. Dorsal view of Apobaetis sp. This is a
genus of large, sandy rivers. The labrum without a
median notch and the long claws help to separate this
genus from other baetids.
MMM
Figure A-59. Dorsal view of Paracloeodes sp.
Ephemeroptera:Baetidae
A-21
-------
Taxonomic Aids for Mid-Atlantic Benthic Macroinvertebrates
Pseudocloeon sp.
The species in this genus were formerly in the genus Labiobaetis sp. and are often listed as such
in older keys. Pseudocloeon sp. is found throughout the mid-Atlantic.
Additional References:
McCafferty, W.P. and R.D. Waltz. (1995). Labiobaetis (Ephemeroptera:Baetidae): new status, new North
American species, and related new genus. Entomological News 106[1], 19-28.
Morihara, O.K. and W.P. McCafferty. (1979). The Baetis Larvae of North America (Ephemeroptera:Baetidae).
Transactions of the American Entomological Society 105, 139-221.
Figure A-60. Dorsal view of Pseudocloeon sp.
Figure A-61. Ventral view of the head of Pseudocloeon
sp. The subapical excavation on the maxillary palp is
an easily visible character to identify this genus.
A-22
Ephemeroptera:Baetidae
-------
Taxonomic Aids for Mid-Atlantic Benthic Macroinvertebrates
Acerpenna sp.
Acerpenna sp. is common throughout the mid-Atlantic. The genus is separated from other
Baetidae by the narrowed gill on abdominal segment 7 which is dissimilar from proceeding gills,
antenna inserted close together forming a raised keel, and a well developed median projection
on the labial palp.
Additional References:
Waltz, R.D. and W.P. McCafferty. (1987). New genera of Baetidae for some Nearctic species previously
included in Baetis Leach (Ephemeroptera). Annals of the Entomological Society of America 80[5],
667-670.
Morihara, O.K. and W.P. McCafferty. (1979). The Baetis Larvae of North America (Ephemeroptera:
Baetidae). Transactions of the American Entomological Society 105, 139-221.
Figure A-62. Dorsal view of Acerpenna pygmaea.
Figure A-63. Gill 7 of Acerpenna pygmaea.
Ephemeroptera:Baetidae
A-23
-------
Taxonomic Aids for Mid-Atlantic Benthic Macroinvertebrates
Diphetor hageni
This genus is monotypic, with Diphetor hageni as the sole species assigned to the genus. D.
hageni occurs throughout the mid-Atlantic and are fairly common in stream bioassessment
samples. The absence of gills on abdominal segment 1 and the reduced prostheca are reliable
characters for identifying this genus.
Additional References:
Waltz, R.D. and W.P. McCafferty. (1987). New genera of Baetidae for some Nearctic species previously
included in Baetis Leach (Ephemeroptera). Annals of the Entomological Society of America 80[5],
667-670.
Morihara, O.K. and W.P. McCafferty. (1979). The Baetis Larvae of North America (Ephemeroptera:
Baetidae). Transactions of the American Entomological Society 105, 139-221.
Figure A-64. Dorsal and lateral views of Diphetor
hageni.
Figure A-65. The reduced, bifid prostheca on the
right mandible of Diphetor hageni is distinctive for NA
Baetidae, but requires slide mounting the mandible and
a magnification of around 400x.
A-24
Ephemeroptera:Baetidae
-------
Taxonomic Aids for Mid-Atlantic Benthic Macroinvertebrates
Baetis sp.
The genus Baetis sp. is often the most common mayfly component of bioassessment samples.
Additional References:
Morihara, O.K. and W.R McCafferty. (1979). The Baetis Larvae of North America (Ephemeroptera:Baetidae).
Transactions of the American Entomological Society 105, 139-221.
Weirsema, N.A., Nelson, C.R. and K.F. Kuehnl. (2004). A New Small Minnow Mayfly (Ephemeroptera:
Baetidae) from Utah, USA. Entomological News 115:139-145.
Figure A-66. Baetis intercalaris, a common species
in the mid-Atlantic.
Figure A-67. The labial palps of Baetis tricaudatus.
Ephemeroptera:Baetidae
A-25
-------
Taxonomic Aids for Mid-Atlantic Benthic Macroinvertebrates
Barbaetis sp.
Barbaetis benfieldi, the only species now assigned to this genus, is recorded from the
southeastern U.S. and is known in the mid-Atlantic only from southern Virginia.
Additional References:
Waltz, R.D., W.R McCafferty and J.H. Kennedy. (1985). Barbaetis: A new genus of eastern Nearctic
mayflies (Ephemeroptera:Baetidae).The Great Lakes Entomologist 18[4], 161-165.
Description of Barbaetis benfieldi, the sole species in the genus.
A-26 Ephemeroptera:Baetidae
-------
Taxonomic Aids for Mid-Atlantic Benthic Macroinvertebrates
Plecoptera: Separation of Capniidae and Leuctridae
Separation of larvae of the families Leuctridae and Capniidae can be difficult, especially in early
instars. The most reliable character to separate the two taxa, the membranous pleural fold on the
venter of the abdomen, is often difficult to see in preserved specimens. The pleural fold reaches
to abdominal segment 9 on Capniidae (Fig. B-1), while in Leuctridae the pleural fold ends at
abdominal segment 7 or before (Fig. B-2).
Figure B-1. Ventral view of the abdominal segments of
Allocapnia sp. (Capniidae). The pleural fold is a crease
that runs just inside the lateral margin of each abdominal
segment from segments 1 through 9. It is visible just
inside the top and bottom margins of the abdomen as
a darker line, easiest to see on the bottom side in this
photo (arrow).
Figure B-2. Ventral view of the abdomen of Leuctra
sp. (Leuctridae). The pleural folds on Leuctridae are
often difficult to see, as in this specimen. In this genus,
the most commonly found Leuctridae in Region 3, the
pleural fold is from segments 1 -4 (arrow).
Plecoptera: Capniidae/Leuctridae
B-1
-------
Taxonomic Aids for Mid-Atlantic Benthic Macroinvertebrates
The shape of the abdomen can also aid in the separation of the two families; this character is
generally easier to see than the pleural folds. The abdomen of Leuctridae is generally parallel
sided, while in Capniidae the abdomen appears wider at the distal end (Fig. B-3).
In Capniidae, the length of the hind wing pad is generally less than twice the greatest width (Fig.
B-4). In Leuctridae, the length of the hind wing pad is 2-1/2 to 3 times the greatest width (Fig. B-5).
Figure B-3. Dorsal view of Leuctridae (top) and
Capniidae (bottom) abdomens. Note abdominal
segments 6 to 8 on Capniidae are wider than the
proximal and distal segments, while in Leuctridae the
width of the segments are relatively uniform throughout.
Figure B-4. Dorsal view of a late instar Capniidae
larva thorax (Allocapnia sp.). The length of the hind
wing pad is shorter than twice its greatest width. In this
genus, commonly collected in bioassessment samples
in Region 3, the hind wing pads are truncate; in most
other Capniidae, the hind wing pads are more rounded.
Figure B-5. Dorsal view of a late instar Leuctridae
larva thorax (Leuctra sp.). The length of the hind wing
pads of this common eastern genus is approximately
three times the greatest width.
B-2
Plecoptera: Capniidae/Leuctridae
-------
Taxonomic Aids for Mid-Atlantic Benthic Macroinvertebrates
Diptera: Simuliidae
1. Labral fans absent (Fig. C-1); anal sclerite 'Y' shaped (Fig. C-2); lateral margins of head
strongly convex Twinnia
1'. Labral fans present (Fig. C-3); anal sclerite 'X' shaped (Fig. C-4); lateral margins of head
slightly convex 2
Figure C-1. Head lacking labral fans (Twinnia sp.).
Figure C-2. Anal sclerite "Y" shaped. Dorsal view of
end of abdomen of Twinnia sp.
Figure C-3. Head with labral fans present
(Simuliumsp.).
Figure C-4. Anal sclerite "X" shaped. Compound anal
gills are visible just to the left of the sclerite (Simulium
sp.).
Diptera:Simuliidae
C-1
-------
Taxonomic Aids for Mid-Atlantic Benthic Macroinvertebrates
2. (1) Postocciput nearly complete dorsally, enclosing cervical sclerites (Fig. C-5); median tooth of
hypostoma compound (Fig. C-6); usually with 3rd antennal segment dark with 1st and 2nd segments light
(Fig. C-7) Prosimulium/Helodon
2'. Cervical sclerites free (Fig. C-8); median tooth of hypostoma single (Fig. C-10 and C-12); antennal
pigment not as above 3
Figure C-5. Dorsum of Prosimulium sp. head. The
postocciput encloses the two cervical sclerites (arrows-
compare to Fig. C-8).
Figure C-6. Ventral view of Prosimulium sp. head.
Note the large, compound median hypostomal tooth.
Figure C-7. Antenna of Prosimulium sp. Most
Prosimulium have the basal segments of the antenna
pale, while the last segment is pigmented.
Figure C-8. Dorsum of Greniera sp. head. The cervical
sclerites are not enclosed and are visible as two brown
spots at the back of the head (arrows).
C-2
Diptera:Simuliidae
-------
Taxonomic Aids for Mid-Atlantic Benthic Macroinvertebrates
3. (2) Abdominal segment 9 with transverse midventral bulge (Fig. C-9); Hypostomal teeth in three distinct
groups (Fig.C-10) Stegopterna
3. Abdominal segment 9 without transverse midventral bulge although two ventral tubercles sometimes
present (Fig. C-11); hypostomal teeth not as above 4
Figure C-9. Lateral view of Stegopterna sp. abdomen.
A median, transverse, ventral bulge (arrow) is present
on abdominal segment 9.
Figure C-10. Hypostomal teeth of Stegopterna
sp. The smaller teeth are grouped around the
median and lateral teeth.
Figure C-11. Ventral view of the posterior of Greniera
sp., showing the ventral tubercles (arrows).
Diptera:Simuliidae
C-3
-------
Taxonomic Aids for Mid-Atlantic Benthic Macroinvertebrates
4. (3) Hypostoma with median tooth and outer lateral teeth moderately large and subequal in height, with
three smaller but nearly equal sublateral teeth between (Fig. C-12); anal gills simple or compound (Fig.
C-13) Simulium
4'. Hypostoma with teeth otherwise; gills always simple (Fig. C-14) 5
Figure C-12. Ventral view of Simulium sp. head. The
lateral (yellow arrows) and median teeth (black arrow)
are simple and approximately equal, with three smaller
teeth between the median and each lateral tooth.
Figure C-13. Compound anal gills, present in some
species of Simulium sp. In this lateral view, one major
lobe is seen, with the accessory lobes to the right. Other
genera have three simple lobes as in Fig. C-14.
Figure C-14. Anal gills consisting of three simple lobes
(Cnephiasp.).
C-4
Diptera:Simuliidae
-------
Taxonomic Aids for Mid-Atlantic Benthic Macroinvertebrates
5. (4) Segment 9 without cone-shaped tubercles (Fig. C-15); teeth of hypostoma uniformly small
(Fig. C-16); length of antenna shorter than bases of labral fans Cnephia
5'. Segment 9 with cone-shaped tubercles (Fig. C-17); teeth of hypostoma and length of
antenna variable , ,,,..,., , , , ,,,..,., , , , ,,,..,., , , , ,,,..,., , , , ,,,..,., 6
Figure C-15. Posterior of Cnephia sp. abdomen. No
lobes or cone-shaped tubercles are present.
Figure C-16. Venter of the head of
Cnephia sp. Note the small, irregular
hypostomal teeth.
Figure C-17. Posterior of Greniera sp. abdomen. Two
cone-shaped tubercles are present on ab segment 9.
Diptera:Simuliidae
C-5
-------
Taxonomic Aids for Mid-Atlantic Benthic Macroinvertebrates
6. Abdomen greatly expanded at segment 5; teeth of hypostoma small and indistinct; anal sclerite
absent Ectemnia
6'. Abdomen not greatly expanded as above (Fig. C-18); lateral teeth of hypostoma large and
pronounced (Fig. C-19); anal sclerite present; rare, generally found in small headwater streams
and seeps Greniera
Figure C-18. Lateral view of Greniera sp. The abdomen
tapers gradually towards the posterior, with no abrupt
bulge at segment 5.
Figure C-19. Ventral view of Greniera sp. head. Note the
large lateral hypostomal teeth and the smaller, recessed
median tooth.
C-6
Diptera:Simuliidae
-------
Taxonomic Aids for Mid-Atlantic Benthic Macroinvertebrates
Literature Cited
Adler, PH., Currie, D.C. and D.M. Wood. (2004). The Blackflies of North America.
Comstock Publishing, Cornell Press, Ithaca, NY. 941pp.
Check, G.R. (1982). A revision of the North American species of Callibaetis
(Ephemeroptera:Baetidae). PhD Dissertation, University of Minnesota.
Edmunds, G.R, Jr. and R.D. Waltz. (1996). Ephemeroptera. In An Introduction to the
Aquatic Insects of North America, Third Edition. Merritt, R.W. and K.W. Cummins,
eds. Kendall/Hunt Publishing, Dubuque, Iowa. 862 pp.
Jacobus, L.M. and W.P McCafferty. (2006). A new species of Acentrella Bengtsson
(Ephemeroptera:Baetidae) from Great Smoky Mountains National Park, USA.
Aquatic Insects, v. 28, p. 101-111.
Lowen, R.G. and J.F. Flannagan. (1991). Four Manitoba species of Centroptilum
Eaton (Ephemereoptera:Baetidae) with remarks on the genus. Pages 189-205
in Overview and Strategies of Ephemeroptera and Plecoptera, J. Alba-Tercedor
and A. Sanchez-Ortega, eds. The Sandhill Crane Press, Inc. Gainesville, Florida,
USA.
Lowen, R.G. and J.F. Flannagan. (1992). Nymphs and imagoes of four North
American species of Procloeon Bengtsson with description of a new species
(Ephemeroptera:Baetidae). The Canadian Entomologist 124:97-108.
Lugo-Ortiz, C.R. and W.P. McCafferty. (1998). A new North American genus of
Baetidae (Ephemeroptera) and key to Baetis complex genera. Entomological
News 109(5): 345-353.
Lugo-Ortiz, C.R., McCafferty, W.P. and R.D. Waltz. (1999). Definition and
reorganization of the genus Pseudocloeon (Ephemeroptera:Baetidae) with
new species descriptions and combinations. Transactions of the American
Entomological Society 125(1-2): 1-37.
McCafferty, W.P. (2000). A new Nearctic species of Apobaetis (Ephemeroptera:
Baetidae). Entomological News 111:265-269.
McCafferty, W.P. and D.R. Lenat. (2003). A new Nearctic Paracloeodes
(Ephemeroptera:Baetidae) Entomological News 114:33-36.
McCafferty, W.P. and R.D. Waltz. (1995). Labiobaetis (Ephemeroptera:Baetidae):
new status, new North American species, and related new genus. Entomological
News106[1], 19-28.
McCafferty, W.P, Wigle, M.J. and R.D. Waltz. (1994). Systematics and biology
of Acentrella turbida (McDunnough) (Ephemeroptera:Baetidae). Pan-Pacific
Entomologist 70[4], 301-308.
Literature Cited D-1
-------
Taxonomic Aids for Mid-Atlantic Benthic Macroinvertebrates
McCafferty, W.P., Waltz, R.D., Webb, J.M. and L.M. Jacobus. (2005). Revision of
Heterocloeon McDunnough (Ephemeroptera: Baetidae). Journal of Insect
Science, 5:35. lnsectscience.org/5.35
Merritt, R.W. and K.W. Cummins. (1996). An introduction to the aquatic insects of
North America, Third Edition, Kendall/Hunt Publishing Company, Dubuque, Iowa,
USA. 862p.
Morihara, O.K. and W.P. McCafferty. (1979). The Baetis Larvae of North America
(Ephemeroptera:Baetidae). Transactions of the American Entomological Society
105, 139-221.
Muller-Liebenau, I. (1974). Rheobaetis, a New Genus from Georgia (Ephemeroptera:
Baetidae). Annals of the Entomological Society of America 67:555-567.
Randolph, PR. (2002). Atlas and Biogeographic review of the North American
Mayflies (Ephemeroptera). PhD Dissertation, Department of Entomology, Purdue
University. 514 pp.
Stewart, K.W. and B.P Stark. (2002). Nymphs of North American Stonefly Genera,
Second Edition. The Caddis Press, Columbus, Ohio. 510 pp.
Waltz, R.D. and W.P. McCafferty. (1987). New genera of Baetidae for some Nearctic
species previously included in Baetis Leach (Ephemeroptera). Annals of the
Entomological Society of America 80[5], 667-670.
Waltz, R.D. and W.P. McCafferty. (1989). New species, redescriptions, and cladistics
of the genus Pseudocentroptiloides (Ephemeroptera:Baetidae). Journal of the
New York Entomological Society 97[2], 151-158.
Waltz, R.D., McCafferty, W.P. and J.H. Kennedy. (1985). Barbaetis: A new genus
of eastern Nearctic mayflies (Ephemeroptera:Baetidae).The Great Lakes
Entomologist 18[4], 161-165.
Weirsema, N.A., C.R. Nelson and K.F. Kuehnl. (2004). A New Small Minnow Mayfly
(Ephemeroptera:Baetidae) from Utah, USA. Entomological News 115:139-145.
Wiersema, N.A. (1999). Two new species of Procloeon (Ephemeroptera:Baetidae)
from Texas. Entomological News 110(1):27-35.
Wiersema, N.A. (2000). A new combination for two North American small minnow
mayflies (Ephemeroptera: Baetidae). Entomological News 111(2):140-142.
D-2 Literature Cited
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