G4074

Mayfly Larvae OF WISCONSIN

Tom H. Klubertanz

Dolania americana larva, Paraleptophlebia volitans larva, pulla larva, Pseudiron centralis larva Larvae of Wisconsin

Tom H. Klubertanz Tom H. Klubertanz is a professor of biology at the University of Wisconsin–Rock County in Janesville, Wisconsin, and chair of the University of Wisconsin Colleges Department of Biological Sciences. He received a master’s degree in Entomology and a doctorate in both Entomology and Ecology & Evolutionary Biology from Iowa State University. He completed his undergraduate studies at the University of Wisconsin– Oshkosh. Klubertanz has taught for over 25 years and studied the Ephemeroptera for over 30 years. Previous publications on include studies of the fauna of Illinois, Iowa, Michigan, Missouri, Nebraska, and Wisconsin. In addition to the study of mayflies, his research interests include the , ecology, and distribution of other freshwater ; soybean pest management; ecological interactions of plants and insects; and bird conservation.

Cooperative Extension publications are subject to peer review.

Copyright © 2016 by the Board of Regents of the University of Wisconsin System doing business as the division of Cooperative Extension of the University of Wisconsin-Extension. All rights reserved. University of Wisconsin-Extension, Cooperative Extension, in cooperation with the U.S. Department of Agriculture and Wisconsin counties, publishes this information to further the purpose of the May 8 and June 30, 1914, Acts of Congress. An EEO/AA employer, the University of Wisconsin-Extension, Cooperative Extension provides equal opportunities in employment and programming, including Title IX and ADA requirements. If you have a disability and require this information in an alternative format, or if you would like to submit a copyright request, please contact Cooperative Extension Publishing at 432 N. Lake St., Rm. 227, Madison, WI 53706; [email protected]; or (608) 263-2770 (711 for Relay). This publication is available from your county UW-Extension office (counties.uwex.edu) or from Cooperative Extension Publishing. To order, call toll-free 1-877-947-7827 or visit our website at learningstore.uwex.edu.

Printed in the United States of America ISBN 978-0-9801401-6-3 This book is dedicated to my family, including my wife and best friend, Theresa, and my children, Katie, John, and Luke. No man could be more blessed. Contents Preface...... vii Acknowledgments...... viii 1 Biology and Importance of Wisconsin Mayflies ...... 1 2 Anatomy of Mayfly Larvae ...... 6 3 Taxonomy, Diversity, and Conservation of Wisconsin Mayflies...... 11 4 Acanthametropodidae ...... 25 5 ...... 26 6 Ametropodidae ...... 29 7 ...... 30 8 ...... 31 9 Baetiscidae...... 107 10 ...... 111 11 ...... 112 12 ...... 137 13 ...... 177 14 ...... 186 15 Isonychiidae ...... 226 16 ...... 232 17 ...... 236 18 Metretopodidae ...... 249 19 Neoephemeridae ...... 254 20 Oligoneuriidae ...... 256 21 Palingeniidae ...... 257 22 Polymitarcyidae ...... 258 23 ...... 263 24 Pseudironidae ...... 266 25 ...... 267 Checklist of Wisconsin Mayfly Species...... 273 Glossary of Terms ...... 276 References Cited ...... 279

v Preface he lakes and streams of Wisconsin groups in such habitats (Morgan from 1970 to 1995. These publications Tprovide larval habitat for over 1913). Their presence or absence also included faunal studies, keys to 150 species of a curious and ancient tells us about the quality of aquatic the Wisconsin genera, and keys group of insects called the mayflies, habitats. Mayflies are sensitive to to the species of several families. the Order Ephemeroptera. Mayfly habitat degradation, with impaired Unfortunately, even those publications larvae commonly are found under waters having lower species diversity are now dated and should be used at the stones, crawling on woody debris, (Hilsenhoff 1982, 1977; Hubbard and species level with considerable caution. and clinging to vegetation in our Peters 1978). Ecologists and citizen My field work and examination of unimpaired waters. Though their shape scientists use mayflies and other aquatic existing collections have uncovered a and size can vary greatly, all mayfly insects to monitor water quality, an large number of new state and county larvae have a simple, primitive body economic alternative to chemical records of Wisconsin mayflies. These plan, two or three long caudal filaments analyses. records now provide a clearer picture (tails), and abdominal gill filaments A detailed taxonomic study of the of the distribution, conservation status, or plates. If they avoid predators and Wisconsin mayfly fauna is badly and ecological requirements of these other hazards of their aquatic world, needed. The last keys for identifying insects in the state. Arguably, the they emerge as adults and complete all known species of mayfly larvae mayfly fauna of Wisconsin now is better their brief terrestrial existence entirely from any Midwest state in the United known than for any other Midwest focused on reproduction. Our largest States were in Burks (1953). That state. species of mayflies burrow as larvae publication, focused on the Illinois The specific purpose of this book, in silty substrates, emerging as adults fauna, is very outdated because of then, is to provide taxonomic keys, in tremendous numbers that soon countless taxonomic changes and a new distribution records, and litter the ground with dying insects. dramatic increase in the number of biological information for larvae of It is during these episodes of mass species known from the region. Along Wisconsin mayflies. The taxonomic emergence along large rivers that most with Burks’ monograph, access to an keys in this book will allow fairly of the public becomes aware of the entire research library of monographs, accurate identification of mayflies presence of these important insects. papers, and book chapters would be from other Midwest states, especially Mayflies are important insects in many needed to correctly identify Wisconsin’s those bordering Wisconsin. This ways. There is, of course, value in mayfly species. Few biologists have book is intended for a wide variety documenting biodiversity, regardless such library resources, and not all of enthusiasts of the Ephemeroptera, of the taxon. I must confess that most of those publications are sufficiently including those with training and of my interest in mayflies is in regards illustrated. Several papers and reports experience in the identification of to their taxonomy and natural history. on Wisconsin mayflies and other insects and those new to the pleasures Mayflies, however, are more than just aquatic insects were published from the of taxonomic and faunal study. It is innocuous, curious organisms. They laboratory of Dr. William Hilsenhoff, richly illustrated, makes consistent use are key parts of the aquatic food chain, then Professor of Entomology at of terminology, and has a complete being one of the dominant herbivorous University of Wisconsin–Madison, glossary of terms.

vii Acknowledgments rant support for this book included I am grateful for the collaborative Resources), Robert Waltz (Indiana Ga University of Wisconsin Colleges spirit, willingness to share specimens Office of State Chemist and Seed Faculty Research Sabbatical, a UW and records, and taxonomic advice of Commissioner and Purdue University), Colleges Faculty Summer Research fellow students of the Ephemeroptera, and Jeff Webb (University of Guelph). Grant, faculty professional development including (in alphabetical order): In addition to those listed above, I grants from UW–Rock County and Steven Burian (Department of am grateful for access to specimens the UW Colleges Department of Biology, Southern Connecticut State provided by Susan Borkin (Milwaukee Biological Sciences, and support from University), Jeffrey Dimick (Wisconsin Public Museum), Michael Draney the UW–Rock County Foundation. Cooperative Fishery Research Unit, (Department of Natural and Applied Institutional support for the project Aquatic Biomonitoring Laboratory, Sciences, UW–Green Bay), H. Gene has been terrific. I am grateful to two University of Wisconsin–Stevens Drecktrah (Department of Biology undergraduate students, Charne Brown Point), Boris Kondratieff (Department and Microbiology, UW–Oshkosh), and Edward Wolf IV, for their field and of Bioagricultural Sciences, Colorado and Kyle Johnson and Steven Krauth laboratory work on the project in 2011. State University), Richard Lillie (Department of Entomology, UW– They and all of the students who have (Portage, WI), W. Patrick McCafferty Madison). participated in my mayfly research (Department of Entomology, Purdue My sincere thanks are extended to projects have made many contributions University), Arwin Provonsha the publisher, UW-Extension, for the and memorable field seasons. I also (Department of Entomology, Purdue willingness to embark on this project, appreciate the help of my daughter, University), Kurt L. Schmude (UW– and specifically to Pamela DeVore, Katie, who assisted in organizing Superior), William Smith (Bureau Abigail Bond, and Vicki Pierce for illustrations and proofing sections of of Natural Heritage Conservation, helping to give this book the best quality this book in 2012. Wisconsin Department of Natural and presentation possible.

viii BIOLOGY AND IMPORTANCE OF WISCONSIN MAYFLIES

1his first chapter examines the as well. In the mayflies, however, it is have two generations of larvae in the Tecology of mayflies in Wisconsin, the subimago that emerges from the summer months (Edmunds et al. 1976). including their habitat use and old larval skin (called exuviae) and flies Eggs deposited by females in autumn preferences, and discusses methods of away. Some mayflies accomplish this feat may remain dormant throughout winter collection of larvae. right on the surface of the water whereas or may hatch in autumn with young others have larvae that cling to vegetation larvae overwintering. Species with nearly Life Cycle or stones during the transition. The mature larvae in autumn usually emerge The major life stages of the mayfly are the subimago has semiopaque wings with in very early spring and are absent in egg, larva (also known as the nymph or numerous fine hairs along its posterior samples of larvae collected in May. naiad), subimago, and imago. The eggs margins. It may have different, typically of mayflies are finely sculptured capsules more subdued, dull coloration than Larval Feeding Types of life that are deposited on or beneath the imagos. After minutes, hours, or Mayflies have a considerable variety of the surface of water. All mayfly larvae days, depending upon the species, the feeding types (Morgan 1913; Cummins are freshwater insects, usually living in subimago finally molts into the imago, 1973; Edmunds et al. 1976; Cummins flowing (lotic) rather than sluggish or completing one of the rarest versions of and Klug 1979). The generally recognized stationary (lentic) waters. They have life history in the insect world—a winged feeding types of larvae are collectors, numerous features that function well insect molting into a winged insect scrapers, shredders, filter feeders, and in an aquatic environment, including (Morgan 1913). invertebrate predators. The collectors tracheal gills for oxygen absorption and Adult mayflies are, to me, graceful and feed on fine detritus and diatoms and body shapes for either swimming in beautiful insects. Their two or three long occur in all of the most diverse mayfly or avoiding water current. The mayfly caudal filaments, uniquely shaped wings, families. Scrapers (grazers), such as larva, as with all juvenile insects, molts and delicate bodies make them easily species in Maccaffertium (Heptageniidae) its exoskeleton periodically to allow identifiable. Adults do not feed; they and (Ameletidae), remove for growth. After each molt, the insect rely solely upon nutrients stored during living diatoms, algae, and protists briefly is soft and vulnerable until its larval development. Their mouthparts attached to rocks, logs, and other cuticle hardens. It will have as many as and digestive tract are vestigial. Most surfaces. The shape and armature of thirty molts during larval development— mayflies reproduce sexually, with their mouthparts, particularly their few groups of insects have more than both males and females present in maxillae, are different than the typical mayflies. The earliest instar, as the insect populations. Males almost always have mayfly. A limited number of mayfly is called between each molt, looks little larger eyes than females (a difference larvae shred plant debris, including like a mature larva. As it grows, it will usually visible in mature larvae as well), leaves, stems, and roots. Larvae of develop more distinctive color patterns with the greatest sexual dimorphism (Baetidae), a common genus and well-developed wingpads. The occurring in the Baetidae. Males also in lentic habitats, and , last instar, just prior to emergence, has have distinctive genitalia at the posterior mayflies most commonly occurring in darkened wingpads. Such “blackwing” tip of the abdomen. Some mayflies shallow, riparian backwaters, feed in this larvae are useful indicators of when can reproduce asexually, a process fashion. Mayflies from the ecological in the season a particular species called parthenogenesis. In species that guild known as the filter feeders gather will emerge as adults (Morgan 1913; reproduce only in this way, such as in nutrients floating in the water, generally Needham et al. 1935). some Neocloeon (Baetidae) and Ameletus using dense, long rows of leg setae. But the mayfly has a trick up its sleeve. In (Ameletidae), males do not occur. This feeding type is best demonstrated all other insects, whether or not there is Adult female mayflies are masters of in Isonychia (Isonychiidae). Predatory a pupal stage between the larva and the egg production, nearly filling their body mayflies include some of our rarer genera adult, there is only one winged stage. As cavities with eggs. such as Pseudiron (Pseudironidae), Spinadis (Heptageniidae), and every student of backyard entomology Despite their common name, flights of quickly learns, once a fly, beetle, or (Behningiidae). These taxa usually feed mayflies do not always occur in spring. extensively on midge larvae (Diptera: butterfly has wings, molting is finished. Many mayflies, especially smaller species, Growth, for the most part, is finished ). Mature larvae of at least

Biology and Importance of Wisconsin Mayflies 1 some Siphlonurus (Siphlonuridae) are mandibular tusks, they lack most of the (Baetidae), and Spinadis (Heptageniidae), predators of midge and mosquito larvae other features of burrowing mayflies and among others. They also can be quite (Edmunds et al. 1976). live in more erosional habitats. difficult to collect, resulting in only superficial knowledge of the biology of Larval Body Types Environmental most of these species. The diversity in mayfly body types Importance A great number of mayfly species occur reflects their diversity in feeding types The species of Ephemeroptera are key in smaller streams and rivers, including and habitat preferences (Morgan 1913; components of aquatic systems, located the many cold-water trout streams in Cummins 1973). The two most diverse near the base of the food chain (Morgan the northern half of the state. In such and common families of mayflies 1913; Cummins et al. 1966), and are habitats, if they are undisturbed and in Wisconsin differ significantly in important food items for fish (Schwiebert in good health, mayfly diversity is at body type. The Baetidae, with 46 1973). They also are important processors its greatest level. Most impressive are species known from Wisconsin, has of detritus, recycling nonliving the mayfly communities in the Brule, streamlined, minnow-shaped larvae materials and making them available for Flambeau, Namekagon, and Popple capable of considerable athletic prowess consumers. Rivers and their tributaries. Mayflies are as swimmers. They swim dolphin-like, Mayflies also are ecologically important much less common and in low diversity with all movement in the vertical plane. as indicators of water quality (Hilsenhoff in medium to large warm-water rivers of Trying to catch one in a pan of water 1982, 1977; Hubbard and Peters 1978). southern and southeastern Wisconsin, is not an easy task. The Heptageniidae, The presence of a diverse and balanced such as the intensively managed Rock with 25 species known from the state, assemblage of mayfly species in a river and Fox Rivers. Farther west, the Sugar are adapted to avoiding current. They or stream is a sign of both current and River in Green and Rock Counties have flattened hydrodynamic heads and past environmental health. Other insect is in better condition and supports legs that are held laterally from the body. groups, such as stoneflies, also are populations of unusual mayflies such More likely to behave like stoneflies indicators of good water quality. as Homoeoneuria (Oligoneuriidae) (Plecoptera) and cling tightly to rocks or and Cercobrachys (Caenidae). Some logs, they swim more laboriously with Wisconsin Habitats for small creeks and streams in southern either lateral or vertical movements. Mayfly Larvae Wisconsin, such as Otter Creek in Sauk Most heptageniids are scrapers, removing County, Turtle Creek in Walworth and living biofilm from the substrate. Most There are 72 counties in Wisconsin (Fig. 1). The major rivers of the state Rock Counties, and Jericho Creek in genera of mayflies fall into one of these Waukesha County, still have good species two general descriptions. are shown in Figure 2. Most of the state’s border miles are large rivers, diversity. Taxa rarely occurring in far Some taxa are best described as crawlers, including the Mississippi, St. Croix, southern Wisconsin, such as several rarely leaving their protective silt- and Menominee Rivers. Other medium species of , Anafroptilum, covered root masses or mats of algae and to large rivers in the state include the and Diphetor in the Baetidae, Dannella venturing out into the current. These Black, Chippewa, Flambeau, Fox, (Ephemerellidae), and Ameletus include tiny larvae of the Caenidae and Rock, and Wisconsin Rivers. The last (Ameletidae) can be found in these Leptohyphidae, and the tank-shaped is 692 miles long and is the longest and waters. These few sites give us a glimpse Baetiscidae. Another unusual body largest inland river system in the state of what must have been spectacular type occurs in burrowing species. (Lillie and Hilsenhoff 1992), draining communities of mayflies across the These mayflies have soft bodies, large over 12,000 square miles of land. The region prior to changes in land use feathery gills, fossorial legs, and long free-flowing Lower Wisconsin River and stream flow. Many of the streams mandibular tusks. They include some below the Prairie du Sac Dam contains in the Grant River drainage basin in of our largest mayflies, such as adults of rare macroinvertebrate communities. southwestern Wisconsin are severely Hexagenia (Ephemeridae) that emerge Sand-bottom segments of such large degraded, with the basin having one from the Mississippi River in great rivers, particularly the Wisconsin, of the lowest levels of mayfly diversity numbers. Other families with burrowing St. Croix, and Chippewa Rivers, of any in the Midwest (Randolph and larvae include Polymitarcyidae and have the greatest number of rare and McCafferty 1998). Beginning with the Palingeniidae. All of these mayflies endangered mayfly taxa. These species studies by Bill Hilsenhoff in the 1970s, construct tubular burrows in soft silt, soft are in the genera Acanthametropus extensive, statewide sampling of small to or hard clay, or sand. Though species of (Acanthametropodidae), Dolania medium streams and rivers has provided (Potamanthidae) also have (Behningiidae), Pseudocentroptiloides us with a clear picture of the mayfly fauna of such waters.

2 Mayfly Larvae of Wisconsin—Chapter 1 BAYFIELD

DOUGLAS ASHLAND IRON

VILAS

WASHBURN SAWYER

PRICE FOREST FLORENCE ONEIDA

MARINETTE BURNETT POLK

BARRON RUSK LINCOLN

LANGLADE OCONTO TAYLOR CHIPPEWA ST. CROIX DUNN MENOMINEE MARATHON

CLARK

SHAWANO DOOR PIERCE EAU CLAIRE

PEPIN WOOD PORTAGE WAUPACA

OUTAGAMIE AUNEE BUFFALO

BROWN KEW JACKSON

WAUSHARA WINNEBAGO TREMPEALEAU JUNEAU MANITOWOC

MONROE ADAMS CALUMET LA CROSSE

SHEBOYGAN GREEN- MARQUETTE LAKE VERNON FOND DU LAC SAUK COLUMBIA DODGE WASHING- RICHLAND TON

CRAWFORD OZAUKEE DANE JEFFERSON WAUKESHA IOWA AUKEE MI LW GRANT

GREEN ROCK WALWORTH RACINE LAFAYETTE

KENOSHA

Figure 1. Wisconsin counties.

Biology and Importance of Wisconsin Mayflies 3 Figure 2. Major rivers of Wisconsin.

4 Mayfly Larvae of Wisconsin—Chapter 1 Relatively few mayflies occur in lakes beneath such structures, or in crevasses, 80% ethanol. This preservative should and ponds. These include species less sheltered from the current. Other be changed to 70% ethanol in the lab dependent upon water current and species remain more exposed to the for long-term storage. Alcohol is much high levels of dissolved oxygen. The current. Vegetation is a common preferred over formalin, which tends to most common small mayflies of lentic substrate for larvae, especially for make specimens brittle and has greater habitats are in Callibaetis (Baetidae), members of the Baetidae. Mayflies environmental impact. Formalin has (Caenidae), and Tricorythodes in the Ephemeridae and related the advantage, however, of being easily (Leptohyphidae). In northern lakes, families burrow in soft silt and clay. transported in more concentrated Stenonema (Heptageniidae) and Sandy substrates support several of solutions that can be diluted in the ephemerellids such as Eurylophella Wisconsin’s rarest species, especially field. Regardless of the preservative or are typical. Also common in lentic those of large rivers. additives, integumentary patterns on habitats, including Lakes Michigan specimens eventually fade. Bleached and Superior, are species of large Collection Methods specimens may be unidentifiable since burrowing mayflies in Hexagenia and Mayflies can be collected using a variety some species are separable only by Ephemera (Ephemeridae). In general, of methods. Simple inspection of coloration. Photographs and notes lentic habitats in Wisconsin have been surfaces of logs and rocks is productive, taken when specimens were fresh can sampled for mayflies less intensively particularly for acquiring undamaged be quite valuable decades later. than lotic habitats. specimens for rearing. Species All specimens should be properly Conservation and restoration of aquatic inhabiting finer substrates or vegetation labeled using indelible ink. Pencil habitats in Wisconsin are needed to can be collected by disturbing the should be used only for temporary sustain the state’s diversity of mayflies substrate, usually with the feet, while labels. Each label should contain and other macroinvertebrates. As holding a D-framed aquatic net or information about the precise sampling discussed later in this book, many of drift net just downstream. Knowledge location, including the name of the Wisconsin’s mayflies are uncommon to of microhabitat associations can body of water. It should have sufficient rare, consisting of only a few isolated improve the chances of collecting less information to help others relocate the populations. Such populations are common species. Some species are sample site, including detail about the very susceptible to habitat degradation associated with calm eddies behind nearest road access, town and range, and localized extinction. I hope that stones, sandbars, shallow backwaters, and/or geographical positioning system the information provided in this book or current-swept vegetation. Mayflies (GPS) coordinates. Finally, the label encourages better stewardship of of large rivers are most difficult to should contain the sample date and Wisconsin’s aquatic resources. collect, requiring the use of boats and name of the sampler(s). The month specialized equipment. Fine-meshed should always be indicated with a Substrates drift nets can be used to collect larvae Roman numeral. If the sample was Mayflies as a group use a wide variety and exuviae floating downstream. taken from one substrate or with one of substrates (Morgan 1913; Lillie Larvae should always be handled gently methodology, then that information and Hilsenhoff 1992). The greatest to reduce specimen damage that can also can be placed on the label. taxonomic diversity occurs on gravel- interfere with identification. to cobble-sized rocky substrates and The most commonly used preservative woody debris. Often, larvae occur for mayfly larvae collected in the field is

Biology and Importance of Wisconsin Mayflies 5 ANATOMY OF MAYFLY LARVAE

2his chapter focuses on the but provides much support for those anatomical terminology outlined by Tanatomical features used as unfamiliar with the Ephemeroptera. Hubbard (1995). Specific definitions characters in larval keys for mayflies, For more detail on mayfly anatomy, of such terms are given in the glossary. providing clarification and explanation see Morgan (1913), Needham et al. The major anatomical features of the of the relevant terminology. The (1935), Burks (1953), and Edmunds typical mayfly larva are shown in Figure 3. content of this chapter assumes some and Waltz (1996). This book follows general knowledge of insect anatomy the recommendations for mayfly

anterior

HEAD

prothorax notum

THORAX mesothorax wingpad

metathorax I (hidden)

V gill ABDOMEN tergum sterna (hidden) X tails posterior

Figure 3. Major anatomical features of the larval mayfly.

6 Mayfly Larvae of Wisconsin—Chapter 2 Head determine gender. Adult males of Between and anterior to the compound some taxa, such as the Baetidae and eyes are three simple eyes called ocelli. The dorsal surface of the head capsule Leptophlebiidae, have compound eyes These consist of two lateral ocelli and has two compound eyes (Fig. 4). subdivided into two regions, with the one slightly anterior median ocellus. Though preserved mayflies almost dorsal portion more brightly colored. The ocelli are light sensitive but do always have black eyes, live specimens This structure becomes visible in males not produce visual images. Characters have bronze, greenish, or golden- towards the end of larval development, related to the ocelli are rarely used in colored eyes. Mature male larvae of as in Figure 88. taxonomic keys. most species have larger eyes than females, making it relatively easy to

anterior notch submarginal setae

LABRUM prostheca incisors

molar epicranial suture compound eye vertex

RIGHT MANDIBLE LEFT MANDIBLE

ocellus frons maxillary palpus galea-lacinia antenna clypeus

LEFT MAXILLA RIGHT MAXILLA

glossa

paraglossa labial palpus

LABIUM

Figure 4. Head and mouthparts of the larval mayfly.

Anatomy of Mayfly Larvae 7 The dorsal surface of the head capsule labium (Fig. 4). The hypopharynx is is armed distally with various spines is divided into the clypeus, frons, located between the mandibles but is and setae, and a maxillary palpus vertex, and occiput. The occiput is not used in the keys. The labrum is the consisting of up to four segments. In a sclerite posterior of the occipital dorsal covering of the mouthparts. It contrast to the mandibles, the left and suture, which generally is limited in articulates with the clypeus of the head right maxillae are similar. Slide mounts mayflies and not visible in dorsal view. capsule. All taxonomically important of maxillae commonly are required in The region anterior to the occiput is labral setae are on the dorsal surface, the keys, such as for identifying the the vertex. It consists of two sclerites including marginal and submarginal species of Maccaffertium, Stenacron, connected medially along the epicranial setae, and slide mounts should be made and Procloeon. The ventral view is most suture and mostly located between the accordingly. Both the location and the useful, unless otherwise indicated. In compound eyes. Dorsal tubercles and microstructure of these setae can be Ameletus, the setae at the distal end other structures on the vertex are used taxonomically important, especially in of the galea-lacinia are curved and in the keys for the species of Caenidae, the Baetidae. The anterior edge of the pectinate, forming a plankton rake Ephemerellidae, and Ephemeridae. labrum usually has a medial notch, the (Fig. 8p). The shape of the maxillary The anterior end of the occipital shape of which is used occasionally in palpi is the key feature for separating suture forks into two lateral epicranial the keys. Labiobaetis from other baetids. sutures, which pass anterior to (as in Beneath the labrum is a pair of Articulation of the palpal segments the Baetidae, Fig. 7n) or bisect the mandibles (Fig. 4). In most species, the may be indistinct, for example causing lateral ocelli (Fig. 7a). Anterior to the mandibles are similar to those of many difficulty in identifying the species of lateral epicranial sutures is the frons. It chewing insects, with both posterior Anafroptilum, Neocloeon, and Procloeon is uncommonly encountered in keys. molar and anterior (apical) incisor (Baetidae). In a few taxa, such as certain The presence of freckles on the frons is regions. The molar region is flat topped members of the Ephemerellidae and a distinctive feature of the heptageniids and heavily sclerotized. It generally Leptohyphidae, the palpi are reduced or and (Fig. 255b). At the is not visible unless the mandible is absent. anterior margin of the frons is a narrow dissected. The incisors are more conical The ventral-most mouthpart is the sclerite called the clypeus. The clypeus and may have associated setae. Between labium. It is composed of two pair of attaches to the dorsal, lid-like labrum these two regions may be a loosely lobes, the glossae and paraglossae, that covers the remaining mouthparts. articulated sclerite called the prostheca, and the fingerlike labial palpi. The The dorsal surface of the head capsule which usually has an elongate, roughly glossae are medial to the paraglossae. bears one pair of antennae. Each rectangular shape. Dissection of Structural features of the glossae and antenna is divided into a basal scape, a mandibles commonly is required in paraglossae are uncommonly used in middle pedicel, and a long, filamentous the keys. Note that in most taxa, the keys. In the Baetidae, they are extremely flagellum. The flagellum is subdivided right and left mandibles are structurally useful in separating the species of into numerous segments. Antennal different. Dorsal and ventral views of Pseudocentroptiloides. The labial palpi, structure occasionally is used in keys. the same mandible can appear quite composed of two or three segments, The presence or absence of whorls of different as well, requiring care when are commonly used in keys. The third long setae on the antennae is used to preparing slide mounts. The mandibles segment, if present, may be indicated by separate Litobrancha from Hexagenia of some mayfly larvae are produced only a weakly formed crease across the in the Ephemeridae, and to determine into tusks, as in the burrowing families palpus. The shape of the third segment species of Cercobrachys in the Caenidae. Ephemeridae (Fig. 7b), Palingeniidae, of the labial palpus is one of the most Preparation of slide mounts of antennae and Polymitarcyidae, as well as in the frequently used characters in the keys is recommended in the Baetidae for striking larvae of Potamanthidae (Fig. for the Baetidae. In the Leptophlebiidae, the identification of Labiobaetis and for 7a). The shape of the tusks and the the number of specific setae on the differentiation of Baetis brunneicolor distribution of spines on their surface dorsal surface of this segment is used McDunnough and B. tricaudatus commonly are used in the keys for to separate Leptophlebia cupida (Say) Dodds. those families. and L. nebulosa (Walker). The shape of setae on the first segment of the The major mouthparts of mayfly Ventral to the mandibles are the paired labial palpi is used in the Caenidae to larvae, from dorsal to ventral, are the maxillae. Each maxilla consists of a separate Sparbarus from other genera. labrum, mandibles, maxillae, and medial, relatively flat galea-lacinia that

8 Mayfly Larvae of Wisconsin—Chapter 2 The ventral view of the labium is most Baetiscidae, the mesonotum is expand- the wingpads becoming nearly black useful in slide mounts, as it more likely ed to form a domed carapace over the just before emergence. Mayflies with will give a clear view of the shape of the thorax (Fig. 7f). The distribution of such wingpads, therefore, are called palpi. Slide mounts should be prepared spines on the carapace is used in the “blackwing” larvae. Records of black- in that orientation unless indicated key for the species of Baetisca. The wing larvae provide useful information otherwise in the keys. mesonotum and metanotum essentially regarding phenology. The metanotal are fused in mayfly larvae and not easily wingpads always are much smaller and Thorax visible as separate segments in dorsal beneath the mesonotal pads. Metatho- The three segments of the thorax are, view. Metanotal characters rarely are racic wingpads, and therefore the from anterior to posterior, the pro-, used in the keys, except in regard to the adult hind wings, are absent in several meso-, and metathorax (Fig. 3). These wingpads. independent lineages of the Baetidae, three prefixes commonly are used to The ventral surfaces of the thoracic such as in some Acentrella, Neocloeon, refer to particular sclerites or leg parts segments are called sterna, a term also and Procloeon. on the thorax (e.g., metatarsus, prono- used for the ventral surfaces of the tum). Thoracic coloration occasionally abdominal segments. Surprisingly, the Legs is used in the keys, but not as often as in thoracic sterna are uncommonly used The keys in this book use the prefixes adult keys. Each thoracic segment has in keys. In the Caenidae, the distribu- pro-, meso-, and meta- to refer to dorsal sclerites forming the notum. The tion of median tubercles on the thoracic particular legs or segments on those pronotum simply has two sclerites fused sterna is used to separate the genera and legs. Mayflies have the typical major along the midline. Coloration of the species of brachycercines—those species regions of the insect leg, from base pronotum is used, for example, in sep- in the family with ocellar tubercles on to tip: coxa, trochanter, femur, tibia, arating the species of Baetis (Baetidae) the head. and tarsus (Fig. 5). The coxa is the and in field recognition of Stenacron proximal segment that articulates (Heptageniidae). Structural features of The posterior margin of the mesono- with the thorax. Though Ametropus the pronotum are used in the keys for tum always bears a pair of wingpads. (Ametropodidae) is not yet known species of Serratella (Ephemerellidae) Wingpads increase in relative size with from Wisconsin, species in that genus and Caenis (Caenidae). Behind the each successive molt. Highly folded have each coxa with an unusual spinous pronotum is the mesonotum. In the subimagal wing membranes are visible pad (Fig. 8b). Rarely, such as in some inside the wingpads of last instars, with

dorsal edge CLAW

TARSUS

distal end

posterior surface (hidden)

ventral edges TIBIA anterior surface proximal end TROCHANTER FEMUR

dorsal edge Figure 5. Leg of the larval mayfly.

Anatomy of Mayfly Larvae 9 Heterocloeon and Camelobaetidius Abdomen several terms referring to gill structure. (Baetidae), the coxae bear Lamellate gills are flattened and plate- The mayfly abdomen consists of dorsal gill-like osmobranchiae (Fig. 20l). like. Many mayflies with lamellate gills sclerites called terga (singl. tergum) and The trochanter is fairly generalized also have filamentous or tuft-like gills in ventral sclerites called sterna (singl. and not used in Wisconsin keys. The addition to the lamellae. Some mayflies sternum) (Fig. 3). There are ten terga largest segment of the insect leg is have multiple gill lamellae, though and nine sterna visible on the mayfly the femur. Many different aspects of these usually are formed from dorsal or larva. Particular sclerites are referred femoral structure and coloration are ventral folds or flaps of a single lamella. to by Roman numerals in this text. As used in the taxonomic keys. In Drunella Examples of such gills occur in species expected, abdominal characters often (Ephemerellidae), the profemur is larger of Callibaetis and Procloeon (Baetidae), are used in keys. In many older keys, than the other femora, with a row of Siphloplecton (Metretopodidae), tergal coloration often was used to large spines. The tibia generally is more Siphlonurus (Siphlonuridae), and differentiate species. Such characters slender, except in the fossorial legs of Leptophlebia (Leptophlebiidae). fade in alcohol, however, and are the Ephemeridae and other burrowing Entirely filamentous gills are less avoided whenever possible in the mayflies (Fig. 7d). In the Isonychiidae common but occur in Paraleptophlebia keys, or are combined with structural and Oligoneuriidae, the tibiae have (Leptophlebiidae). Operculate gills, as characters. Abdominal coloration long setae used for collecting food in the Caenidae and Leptohyphidae, is extremely helpful in making (Fig. 8e). The tarsus is unsegmented are expanded to serve as protective gill preliminary identifications of larvae in and almost always has a single claw. covers over more posterior gills. The the field or in sorting fresh specimens, In the Metretopodidae, the protarsal gills of larvae in the Baetiscidae are but should be used only by experienced claw is bifid. The claws of mayfly larvae beneath the thoracic carapace and not individuals familiar with all of the most often have one row of tooth-like normally visible from dorsal view. species in the region. Identifications denticles, but two rows occur in some based solely upon comparison with Most mayflies have three caudal taxa such as Heterocloeon (Baetidae). photographs, such as those provided filaments, or “tails,” a well-known field Slide mounts of tarsi commonly are in this book, will have an unacceptable mark used by beginning students of required in keys, with appropriate error rate. aquatic insects. Stoneflies, in contrast, orientation of the tarsus on the slide always have two caudal filaments. The being important. Each of the first seven abdominal three tails in mayflies consist of two segments can bear a pair of external Throughout this text, the dorsal, lateral caudal filaments (modified respiratory gills. The structure and ventral, anterior, and posterior surfaces cerci) and one median caudal filament. distribution of these gills are frequently of legs refer to those indicated in Figure Length, setation, and banding of the used in keys. Unfortunately, specimens 5, following Hubbard (1995). This caudal filaments are used in the keys. with missing gills are common and can nomenclature refers to the surfaces of In most species, the median caudal be frustratingly difficult to identify, the primitive insect leg, not the surfaces filament is shorter than the other particularly in the Leptophlebiidae. of the leg typically maintained by the two. In a few mayflies, such as species As with the abdominal segments, insect in its natural posture. As such, of Epeorus (Heptageniidae) and the the gills are referred to by Roman the laterally projecting and flattened baetids Acentrella, Heterocloeon, numerals. Almost all species have the legs of the heptageniid mayflies have Iswaeon, and , the median gills directed dorsally, but ventrally the anterior surface facing upward caudal filament is greatly reduced or oriented gills are present in larvae and the posterior surface against the vestigial (as in Fig. 20f). These two- of Rhithrogena (Heptageniidae) and substrate. tailed mayflies are the exception to Dolania (Behningiidae). There are the rule.

10 Mayfly Larvae of Wisconsin—Chapter 2 TAXONOMY, DIVERSITY, AND CONSERVATION OF WISCONSIN MAYFLIES

3 Wisconsin had grown to seventeen, Popple River systems in Florence Previous Studies of with no single publication adding and Forest Counties (Hilsenhoff et Wisconsin Mayflies more than three species (Traver 1935; al. 1972). That publication was the Forty-one publications have contributed Spieth 1941; Hamilton 1959; Britt source of 32 of our current state new Wisconsin state records of mayflies 1962; Leonard and Leonard 1962; records, bringing the total at that time (Table 1). The earliest, documented Allen and Edmunds 1963b; Allen to 49 species—but just 31% of today’s mayfly record from the state is of the and Edmunds 1965; Peterka 1969). known diversity. The 1970s continued ubiquitous heptageniid Stenacron Of these records, that of Pentagenia as the most prolific decade for new interpunctatum (Say) by Wodsedalek vittigera (Walsh) (Ephemeridae) by state records, with seven more species (1912). Muttkowski (1918) added three Hamilton (1959) was most notable, added from 1974 and 1975 (Edmunds species, including the only historical as records of this species remain and Jensen 1974; Lewis 1974a; Selgeby record for Leucrocuta maculipennis scarce. In the 1970s, UW–Madison’s 1974; Flowers and Hilsenhoff 1975; (Walsh) from Wisconsin. Randolph and Bill Hilsenhoff began a long series McCafferty 1975). Edmunds and McCafferty (1998), however, considered of contributions with the landmark Jensen (1974) added Spinadis simplex this identification dubious. By 1970, survey of species from the Pine and (Walsh) (Heptageniidae), which today the number of species known from

Table 1. Chronological list of literature contributions to the known mayfly diversity of Wisconsin.

Author Species Wodsedalek (1912) Stenacron interpunctatum (Say) Muttkowski (1918) Caenis diminuta Walker, Leucrocuta maculipennis (Walsh), Siphlonurus alternatus (Say) Traver (1935) Callibaetis ferrugineus (Walsh), Eurylophella lutulenta (Clemens) Spieth (1941) Hexagenia limbata (Serville) Hamilton (1959) Hexagenia bilineata (Say), Pentagenia vittigera (Walsh) Britt (1962) Ephemera simulans Walker, Ephoron album (Say) Leonard and Leonard (1962) Procloeon rufostrigatum (McDunnough) Allen and Edmunds (1963b) Eurylophella funeralis (McDunnough), E. temporalis (McDunnough) Allen and Edmunds (1965) Ephemerella invaria (Walker), E. subvaria McDunnough Peterka (1969) Baetis tricaudatus Dodds Hilsenhoff et al. (1972) Acentrella parvula (McDunnough), A. turbida (McDunnough), Acerpenna pygmaea (Hagen), Anafroptilum album (McDunnough), Attenella attenuata (McDunnough), Baetis brunneicolor McDunnough, B. intercalaris McDunnough, B. pluto McDunnough, Baetisca obesa (Say), Dan- nella simplex (McDunnough), Drunella cornuta (Morgan), Ephemerella needhami McDunnough, Ephoron leukon Williamson, Eurylophella bicolor (Clemens), (McDunno- ugh), Labiobaetis frondalis (McDunnough), Maccaffertium mediopunctatum arwini (Bednarik & McCafferty), M. modestum (Banks), M. pulchellum (Walsh), M. vicarium (Walker), Neocloeon alamance Traver, Paraleptophlebia debilis (Walker), P. mollis (Eaton), Plauditus cingulatus (Mc- Dunnough), P. dubius (Walsh), P. punctiventris (McDunnough), Procloeon bellum (McDunnough) [removed from the state list herein], Rhithrogena manifesta Eaton, Serratella serrata (Morgan), Siphloplecton basale (Walker), Stenonema femoratum (Say), deficiens (Morgan) Edmunds and Jensen (1974) Spinadis simplex (Walsh) Lewis (1974a) Maccaffertium exiguum (Traver), M. terminatum terminatum (Walsh) Selgeby (1974) Heptagenia pulla (Clemens) Flowers and Hilsenhoff (1975) Maccaffertium mexicanum integrum (McDunnough) McCafferty (1975) Hexagenia atrocaudata McDunnough, H. rigida McDunnough (continued) Taxonomy, Diversity, and Conservation of Wisconsin Mayflies 11 Table 1. (continued) Author Species Shapas and Hilsenhoff (1976) Epeorus vitreus (Walker), Ephemerella aurivillii (Bengtsson), E. catawba Traver, Heptagenia elegantula (Eaton), Labiobaetis propinquus (Walsh), Leucrocuta hebe (McDunnough), Maccaffertium luteum (Clemens), Nixe lucidipennis (Clemens), Rhithrogena impersonata (McDunnough), R. jejuna Eaton, Siphlonurus quebecensis (Provancher) Bergman and Hilsenhoff (1978a) Acerpenna macdunnoughi (Ide), Diphetor hageni (Eaton) Flowers and Hilsenhoff (1978) bipunctata (McDunnough), Heptagenia flavescens(Walsh) Morihara and McCafferty (1979b) Labiobaetis longipalpus (Morihara & McCafferty) Peckarsky (1980) Baetis flavistriga McDunnough Pescador and Berner (1981) Baetisca laurentina McDunnough Hilsenhoff (1984) Baetisca lacustris McDunnough Kondratieff and Voshell (1984) Isonychia sayi Burks Lillie et al. (1987) Acanthametropus pecatonica (Burks) Jacobs (1990) Choroterpes basalis (Banks), Dolania americana Edmunds & Traver, Habrophlebiodes americana (Banks), Leptophlebia cupida (Say) Provonsha (1990) Caenis amica Hagen, C. hilaris (Say), C. latipennis Banks, C. punctata McDunnough Bae and McCafferty (1991) Anthopotamus myops (Walsh), A. verticis (Say) Lillie (1992) Homoeoneuria ammophila (Spieth), Macdunnoa persimplex (McDunnough), Metretopus borealis (Eaton), Pseudiron centralis McDunnough Lillie and Hilsenhoff (1992) Caenis tardata McDunnough, C. youngi Roemhild, Isonychia bicolor (Walker), minu- tus (Daggy), Siphloplecton interlineatum (Walsh), Sparbarus nasutus (Soldan), Susperatus prudens (McDunnough), Tricorythodes explicatus (Eaton) Lillie (1995) Labiobaetis dardanus (McDunnough), Parameletus sp. A (as P. chelifer Bengtsson) Hilsenhoff (1996) Traver, Leptophlebia nebulosa (Walker) Randolph and McCafferty (1998) Caenis anceps Traver, Callibaetis fluctuans (Walsh), Ephemerella dorothea Needham, E. excrucians Walsh, Eurylophella aestiva (McDunnough), Heterocloeon amplum (Traver), Isonychia sicca (Walsh), Nixe inconspicua (McDunnough), Paraleptophlebia guttata (McDunnough), Rhithrogena undulata (Banks), Sparbarus lacustris (Needham) Klubertanz and Hess (2001) Dannella lita (Burks), Procloeon viridoculare (Berner) McCafferty and Jacobus (2001) Plauditus cestus (Provonsha & McCafferty) McCafferty et al. (2004) Anafroptilum conturbatum (McDunnough), A. victoriae (McDunnough), Callibaetis pallidus Banks, C. skokianus Needham, Neocloeon triangulifer (McDunnough), Procloeon pennulatum (Eaton), P. simplex (McDunnough), Pseudocentroptiloides usa Waltz & McCafferty McCafferty et al. (2005) Iswaeon anoka (Daggy) Sun and McCafferty (2008) Brachycercus harrisella Curtis, B. ojibwe Sun & McCafferty, Cercobrachys etowah Soldan, C. fox Sun & McCafferty, C. lilliei Sun & McCafferty, C. winnebago Sun & McCafferty, Sparbarus maculatus (Berner) McCafferty (2009) Paraleptophlebia praepedita (Eaton) McCafferty (2011) Isonychia rufa McDunnough, Tricorythodes albilineatus Berner, T. allectus (Needham), T. robacki (Allen), T. stygiatus McDunnough Schmude et al. (2012) Neoephemera bicolor McDunnough

is one of only two state-endangered in Wisconsin. The remainder of the Five species were documented from mayflies in Wisconsin. Shapas and decade produced five additional state the state for the first time in the 1980s Hilsenhoff (1976) added eleven species records (Bergman and Hilsenhoff (Peckarsky 1980; Pescador and Berner and made significant contributions to 1978a; Flowers and Hilsenhoff 1978; 1981; Hilsenhoff 1984; Kondratieff our understanding of mayfly biology Morihara and McCafferty 1979b). and Voshell 1984; Lillie et al. 1987).

12 Mayfly Larvae of Wisconsin—Chapter 3 Table 2. New Wisconsin records of mayflies reported in this publication.

Family Species Ameletidae Ameletus subnotatus Eaton Baetidae Anafroptilum bifurcatum (McDunnough), A. minor (McDunnough), Callibaetis pictus (Eaton), Cloeon dipterum (Linnaeus), Fallceon quilleri (Dodds), Labiobaetis ephippiatus (Traver), Procloeon fragile (McDunnough), P. r iv u l are (Traver), P. rubropictum (McDunnough), Pseudocentroptiloides morihari Wiersema & McCafferty Ephemerellidae Drunella cornutella (McDunnough) Ephemeridae Litobrancha recurvata (Morgan) Heptageniidae Leucrocuta aphrodite (McDunnough) Leptophlebiidae Paraleptophlebia adoptiva (McDunnough), P. ontario (McDunnough) Siphlonuridae Siphlonurus phyllis McDunnough, S. rapidus McDunnough

During this period was the discovery and summarized all previous state and This book documents eighteen new of Acanthametropus pecatonica in county records. state records (Table 2) discovered the Wisconsin River by Lillie et al. The next decade added nineteen during field work and extensive (1987). Today, this species is on the species, as currently recognized, to the examination of existing collections, Wisconsin Endangered Species List. list of Wisconsin species (Klubertanz including the reassignment of the state The tremendous mayfly diversity in and Hess 2001; McCafferty and record for Procloeon rubropictum. It Wisconsin was being realized, with 77 Jacobus 2001; McCafferty et al. 2004; also removes Procloeon bellum from species on record by 1990. McCafferty et al. 2005; Sun and the state records based upon the Thirty-seven new state records were McCafferty 2008; McCafferty 2009). uncertain taxonomic status of that documented in the 1990s in a long list Difficult to identify baetids from species. With these records, Wisconsin’s of publications (Jacobs 1990; Provonsha Callibaetis, Anafroptilum, Procloeon, known mayfly diversity is 157 species. 1990; Bae and McCafferty 1991; Lillie and Pseudocentroptiloides and other A complete checklist of these species 1992; Lillie and Hilsenhoff 1992; Lillie genera were added by Klubertanz is given in taxonomic order before the 1995; Hilsenhoff 1996; Randolph and and Hess (2001) and McCafferty et glossary at the end of this book. McCafferty 1998). During this time, al. (2004). The record of Procloeon With 157 species already documented records of several rare and unusual rubropictum in Klubertanz and Hess for Wisconsin, how many undiscovered mayflies were added, including the (2001) is corrected to Neocloeon state records remain? Fallceon quilleri discovery of Dolania americana in triangulifer in this book, and is replaced (Baetidae) was not known from the St. Croix River by Jacobs (1990). by numerous other specimens. In their Wisconsin until this book was nearly Lillie (1992) added four rare species to revision of the brachycercine Caenidae, completed, when my colleague Jeffrey the Wisconsin state list: Macdunnoa Sun and McCafferty (2008) added seven Dimick at the University of Wisconsin– persimplex, Homoeoneuria ammophila, species to the Wisconsin list, described Stevens Point found it in the southwest Pseudiron centralis, and Metretopus several new species, and designated a corner of the state. I believe that many borealis. Taxonomic revisions not Wisconsin specimen as the holotype of Fallceon-like additions to Wisconsin’s specifically targeting Wisconsin Cercobrachys lilliei. known mayfly fauna will be made mayflies, such as that of Caenis by The current decade already has in the coming decades. Based upon Provonsha (1990) and of ephemeroid added several species to the state list. faunal lists of other Midwest states, families by Bae and McCafferty (1991), McCafferty (2011) added five species, I estimate that at least 39 additional not only added Wisconsin records, including the remarkable records of species are possible or likely in the but allowed reliable identification of Tricorythodes albilineatus and the state (Table 3). Surprisingly, discovery many larvae in existing collections. enigmatic T. robacki. Finally, in the of all of these species would be nearly The last publication of the 1990s most recent Wisconsin publication, a 25% increase in the known mayfly adding to the Wisconsin list was the Schmude et al. (2012) added diversity for Wisconsin. Most of comprehensive survey of Midwest Neoephemera bicolor to the state’s faunal these species have records in eastern mayflies by Randolph and McCafferty list, bringing the total to 140 species. Iowa (as was the case for F. quilleri), (1998), which added eleven species northern Illinois, Minnesota, the

Taxonomy, Diversity, and Conservation of Wisconsin Mayflies 13 Key to the Families of Wisconsin Mayfly Larvae 1. Mandibular tusks present, visible in dorsal view (Fig. 7a–c)...... 2 Mandibular tusks absent...... 5 2. Prothoracic legs normal, cylindrical; mandibular tusks as in Fig. 7a...... POTAMANTHIDAE: Anthopotamus Prothoracic legs fossorial (Fig. 7d); mandibular tusks not as above...... 3 3. Mandibular tusks curved upward (Fig. 7b) ...... 4 Mandibular tusks not curved upward (Fig. 7c)...... POLYMITARCYIDAE 4. Mandibular tusk with robust spines on dorsolateral margin (Fig. 7e)...... PALINGENIIDAE: Pentagenia vittigera Mandibular tusk smooth, without dorsolateral spines (Fig. 7b)...... EPHEMERIDAE 5. Thorax expanded into dome-shaped carapace (Fig. 7f)...... BAETISCIDAE: Baetisca Thorax not expanded into carapace...... 6 6. Head and prothorax with dorsal pad of long spines (Fig. 7g); gills ventral. . . . .BEHNINGIIDAE: Dolania americana Head and prothorax without dorsal pad of long spines; gills variable...... 7 7. Gill II forming a complete or partial plate-like operculum, covering more posterior gills (Fig. 7h–i)...... 8 Gill II, if present, not forming a complete or partial operculum; more posterior gills sometimes operculate...... 10 8. Operculate gill II roughly triangular, with corners varying from angular to broadly rounded (Fig. 7h); gill I absent...... LEPTOHYPHIDAE: Tricorythodes Operculate gill II roughly quadrate (Fig. 7i); gill I a slender filament ...... 9 9. Mesonotum with rounded lobe on anterolateral corner (Fig. 7j); operculate gills fused medially; rare...... NEOEPHEMERIDAE: Neoephemera bicolor Mesonotum without lobe on anterolateral corner (Fig. 7k); operculate gills not fused medially; common. . . .CAENIDAE 10. Gill II present; terga rarely with paired tubercles...... 11 Gill II absent; terga often with paired, submedian tubercles or clusters of spicules (Fig. 7l). . . . . EPHEMERELLIDAE 11. Body and head dorsoventrally flattened (Fig. 7m) ...... 12 Head not dorsoventrally flattened (Fig. 7n); body usually cylindrical...... 14 12. Claws elongate; tarsi bowed (Fig. 7o) ...... PSEUDIRONIDAE: Pseudiron centralis Claws short; tarsi not bowed (Fig. 7p)...... 13 13. Maxillary palpi very long and pectinate, visible from above (Fig. 8a) . . . . ARTHROPLEIDAE: Maxillary palpi variable, but rarely visible from above...... HEPTAGENIIDAE 14. Protarsal claw much shorter than other claws, either simple or bifid (Fig. 8b–c); meso- and metatarsal claws simple and about as long as their respective tibiae (Fig. 8d) ...... 15 All claws similar in structure and length; meso- and metatarsal claws of variable length...... 16 15. Protarsal claws simple (Fig. 8b); procoxa with a spinous pad; not known from Wisconsin...... AMETROPODIDAE: Ametropus neavei Protarsal claws bifid (Fig. 8c); procoxa without spinous pad...... METRETOPODIDAE

Taxonomy, Diversity, and Conservation of Wisconsin Mayflies 21 16. Prothoracic leg with a dense row of long, ventral setae, setae longer than protarsus (Fig. 8e)...... 17 Prothoracic leg without a dense row of ventral setae, or such setae shorter than protarsus...... 18 17. Gills I–VII plate-like and rounded, with delicate, branched basal tufts (Fig. 8f); gill I not projecting between metacoxae...... ISONYCHIIDAE: Isonychia Gills II–VII narrow with posterior fringes (Fig. 8g); gill I elongate and projecting between metacoxae ...... OLIGONEURIIDAE: Homoeoneuria ammophila 18. Gills forked, tufted, as slender filaments, or plate-like with terminal filaments (Figs. 8h, 334e) . . . ..LEPTOPHLEBIIDAE Gills plate-like and without terminal filaments (Fig. 8i)...... 19 19. Lateral ocelli located posterior to anterolateral branches of epicranial suture (Fig. 7n); each femur with a down-curved dorsal lobe at apex, visible in anterior view (Fig. 8j); labrum usually with a deep medial notch (Fig. 8k); antennae usually more than twice as long as width of head capsule...... BAETIDAE Lateral ocelli located anterior to or bisected by anterolateral branches of epicranial suture (Fig. 8l); each femur with a truncate or rounded dorsal lobe at apex (Fig. 8m); labrum with medial notch of various depths (Fig. 8n); antennae usually less than twice as long as width of head capsule...... 20 20. Tarsi bowed; metatarsal claw as long as metatarsus (Fig. 8o).ACANTHAMETROPODIDAE: Acanthametropus pecatonica Tarsi not bowed; metatarsal claw shorter than metatarsus...... 21 21. Maxillary crown with a dense row of pectinate spines (Fig. 8p); each gill with a lateral sclerotized band ...... AMELETIDAE: Ameletus Maxillary crown with a dense row of simple spines (Fig. 8q); gills without lateral sclerotized bands. . . SIPHLONURIDAE

22 Mayfly Larvae of Wisconsin—Chapter 3 c d b a

e g h f

i j k l

o

m n p

Figure 7. Mayfly families. a, Anthopotamus myops (Potamanthidae), head (dorsal); b, Hexagenia limbata (Ephemeridae), head (lateral); c, Ephoron album (Polymitarcyidae), mandible (lateral); d, Hexagenia limbata (Ephemeridae), front leg (lateral); e, Pentagenia vittigera (Palingeniidae), mandible (lateral); f, Baetisca lacustris (Baetiscidae), larva (dorsal); g, Dolania americana (Behningiidae), head and pronotum; h, Tricorythodes sp. (Leptohyphidae), terga; i, Caenis latipennis (Caenidae), terga; j, Neoephemera bicolor (Neoephemeridae), mesonotum; k, C. latipennis (Caenidae), mesonotum; l, Ephemerella needhami (Ephemerellidae), terga; m, Heptagenia elegantula (Heptageniidae), head (dorsal); n, Baetis intercalaris (Baetidae), head (anterior); o, Pseudiron centralis (Pseudironidae), front tarsus; p, Stenacron interpunctatum (Heptageniidae), middle leg (anterior).

Taxonomy, Diversity, and Conservation of Wisconsin Mayflies 23 d

a b c

e f g h i

j k l m

n o p q

Figure 8. Mayfly families. a, Arthroplea bipunctata (Arthropleidae), head and pronotum; b, Ametropus neavei (Ametropodidae), front leg (posterior); c, Siphloplecton interlineatum (Metretopodidae), front and middle tarsi; d, A. neavei (Ametropodidae), middle tarsus; e, Isonychia rufa (Isonychiidae), front leg (anterior); f, I. rufa (Isonychiidae), gill V; g, Homoeoneuria ammophila (Oligoneuriidae), gill V; h, Leptophlebia sp. (Leptophlebiidae), gill V; i, Baetis intercalaris (Baetidae), gill V; j, Labiobaetis propinquus (Baetidae), front femur (ante- rior); k, L. propinquus (Baetidae), labrum (dorsal); l, Siphlonurus sp. (Siphlonuridae), head (anterior); m, Siphlonurus sp. (Siphlonuridae), right front femur (anterior); n, Siphlonurus sp. (Siphlonuridae), labrum (dorsal); o, Acanthametropus pecatonica (Acanthametropodidae), hind leg; p, Ameletus lineatus (Ameletidae), maxilla (ventral); q, Siphlonurus sp. (Siphlonuridae), maxilla.

24 Mayfly Larvae of Wisconsin—Chapter 3 BAETIDAE

8he Baetidae is a diverse family of Bergman and Hilsenhoff (1978a), minnow mayflies, generally have small Tmayflies, both in North America Morihara and McCafferty (1979b), and agile larvae. As with most mayflies, as well as globally (Anonymous and Hilsenhoff (1982). With the new they are more diverse in lotic habitats, 2014a; Kluge 2014). There have been state records presented in this book, though some such as Callibaetis are numerous nomenclatural and other Wisconsin’s known baetid fauna now common in lentic systems. taxonomic changes in the group includes sixteen genera and 46 species. since the baetid keys of Burks (1953), The beatids, commonly called small

Key to the Genera of Baetidae 1. Claws spatulate (Fig. 19a); not known from Wisconsin ...... Camelobaetidius Claws simple...... 2 2. Caudal filaments with thin, dark bands on every three to five segments (Fig. 19b); labial palpi truncate (Fig. 19c); gill tracheae usually palmate and asymmetrical...... 3 Caudal filaments rarely with thin, dark bands as above (when such bands are faintly present as in some Callibaetis, then labial palpi rounded); labial palpi and gills variable, but usually not as above ...... 7 3. Antennae longer than half of body length (Fig. 70); gills I–VI bilamellate with large dorsal flaps (Fig. 19d); labial palpus with distinctly pointed projection at anterior corner of apex (Fig. 19e); metathoracic wingpads absent; maxillary palpus three-segmented with terminal segment subequal in length to second segment (Fig. 19f); rare. . . . Cloeon dipterum Antennae shorter than half of body length; gills I–VI with or without dorsal flaps, but not as wide as above; labial palpus lacking pointed projection at anterior corner of apex (Fig. 19c); metathoracic wingpads present or absent; maxillary palpus two- or three-segmented, with third segment, if present, of variable length; fairly common in unpolluted streams and rivers...... 4 4. Glossa distinctly shorter than paraglossa, with apex broadly rounded or truncate (Fig. 19i); labrum relatively elongate, with apicolateral corners appearing acutely angled because of a broad V-shaped notch that is nearly as wide as labrum (additional narrower, deeper notch sometimes present right at midline, especially towards ventral surface) (Fig. 19h); claws subequal to or longer than respective tarsi (Fig. 19g); labial palpus truncate and greatly widened at tip...... Pseudocentroptiloides Glossa subequal in length to paraglossa, with apex lanceolate (Fig. 19c); labrum relatively short, with apicolateral margins evenly rounded, and with only a narrow, U-shaped medial notch (Fig. 19j); claws varying widely in length, but usually shorter than respective tarsi; labial palpus truncate but only slightly widened at tip...... 5 5. Maxillary palpus two-segmented and metathorax lacking wingpads, or maxillary palpus three-segmented with terminal segment much shorter than second segment (Fig. 19k) and metathorax with wingpads (examination of slide-mounted maxillae recommended); tergum IX never with medial tooth-like projection along posterior margin; all gills simple or one or more gills (especially gill I) with a dorsal flap; caudal filaments with lateral bristles to apices; mandibular incisors fused at a variable distance from base; at least some (especially posterior) abdominal segments with robust lateral spines (Fig. 19l)...... Procloeon Maxillary palpus three-segmented (examination of slide-mounted maxillae recommended), with third segment at least two-thirds length of second (Fig. 19m), although sometimes obscure or poorly articulated from second segment; metathoracic wingpads present or absent; tergum IX sometimes with medial tooth-like projection along posterior margin (Fig. 19n); gills always simple, never with dorsal flap; caudal filaments without lateral bristles to apices;

Baetidae 31 mandibular incisors of both mandibles fused to each at a distance equal to or less than half way up from their bases; abdominal segments variable with minute, small, or robust lateral spines on at least posterior segments...... 6 6. Metathoracic wingpads small but present (or if absent, then lateral margins of abdominal terga with very minute spines that are restricted to posterior segments) ...... Anafroptilum Metathoracic wingpads absent; abdominal terga with moderately robust lateral spines (similar in length to those in Fig. 19l) ...... Neocloeon 7. Lamella of each gill with one or more recurved flaps, appearing multilamellate (Fig. 19o)...... Callibaetis Gills composed of simple lamellae, without recurved flaps ...... 8

a b c d

e f g h i

m j k l

n o p q

Figure 19. Baetidae. a, Camelobaetidius waltzi, front tarsus; b, Procloeon viridoculare, tails; c, P. viridoculare, labium (dorsal); d, Cloeon dipterum, gill III; e, C. dipterum, labium (ventral); f, C. dipterum, maxilla (right, ventral); g, Pseudocentroptiloides morihari, hind tarsus; h, P. morihari, labrum; i, P. morihari, glossae and paraglossae (ventral); j, Procloeon viridoculare, labrum (dorsal); k, P. pennulatum, maxilla (ventral); l, P. viridoculare, terga VI–X; m, Anafroptilum bifurcatum, maxilla (ventral); n, A. bifurcatum, terga VIII–X; o, Callibaetis fluctuans, gill V (unfolded); p, Apobaetis etowah, front leg; q, Baetis intercalaris, front tarsus.

32 Mayfly Larvae of Wisconsin—Chapter 8 Labiobaetis without explanation, resumed the larvae are larger and more robust use of Labiobaetis for the propinquus than in most species of Baetis. Comments: In North America, group. This is the current generic Identification of the genus requires Labiobaetis includes a discrete group placement of these species on Mayfly good magnification with a dissecting of species that was in Baetis for many Central (Anonymous 2014a) and in microscope to detect the subapical years and was known as the propinquus this text. The use of Labiobaetis in this constriction of the maxillary palpi (Fig. group. They were moved to Labiobaetis context also follows the conservative 21b), or examination of a slide mount by McCafferty and Waltz (1995). approach of Kubendran et al. (2014). of an antenna to detect a notch along Lugo-Ortiz et al. (1999), based upon Proper identification of Labiobaetis the distal margin of the scape (Fig. adult morphology, reassigned the species in the propinquus group can be 21a). The structure of the labral setae propinquus group to Pseudocloeon challenging, involving slide mounting is most commonly used for species Klapalek, a name once applied to many of mouthparts. Four of the five species determination. of the two-tailed baetids in North are known from Wisconsin. America (now in Acentrella, Plauditus, Larval Keys: Traver (1935), Burks and several other genera). This was Determination: Identification of (1953), Bergman and Hilsenhoff a controversial placement since the Labiobaetis larvae is Slightly Difficult (1978a), Morihara and McCafferty larvae of P. kraepelini Klapalek, the for the genus, and Slightly to (1979b), Soluk (1981), and Hilsenhoff type species of Pseudocloeon, are Moderately Difficult for identification (1982), all as Baetis; McCafferty and not known. McCafferty et al. (2010), of species within the genus. Labiobaetis Waltz (1995).

Key to the Species of Labiobaetis 1. Labrum with dense dorsal setation, especially in distal third (Fig. 83a); labial palpus with second segment not expanded medially, appearing narrow and elongate (Fig. 83b)...... L. longipalpus Labrum with moderate number of setae evenly distributed over dorsal surface (Fig. 8k) or with submarginal dorsal setae differing in structure from other setae (Fig. 83e); labial palpus with second segment expanded medially (Fig. 83c). . . 2 2. Labrum with submarginal dorsal setae terminating in numerous spiny projections, appearing branched (Fig. 83e); medial surface of maxillary palpus usually abruptly and strongly narrowed at tip (Fig. 83f)...... 3 Labrum with submarginal dorsal setae simple (Fig. 8k) or slightly spatulate (Fig. 83h); medial surface of maxillary palpus with less distinctive narrowing at tip (Fig. 83d) ...... 4 3. Right mandible with abrupt prominence between incisor and molar region (Fig. 83g)...... L. ephippiatus Right mandible with only a rounded projection between incisor and molar region (Fig. 83i) ...... L. dardanus 4. Labrum with spatulate dorsal submarginal setae arranged as in Fig. 83h...... L. frondalis Labrum with simple dorsal submarginal setae arranged as in Fig. 8k ...... L. propinquus

Baetidae 77 a b c

d e f

h

g i

Figure 83. Labiobaetis (Baetidae). a, L. longipalpus, labrum (dorsal); b, L. longipalpus, labium (ventral); c, L. propinquus, labium (ventral); d, L. propinquus, maxilla (ventral); e, L. ephippiatus, labrum (dorsal); f, L. ephippiatus, maxilla (ventral); g, L. ephippiatus, mandible (right, ventral); h, L. frondalis, labrum (dorsal); i, L. dardanus, mandible (right, ventral).

78 Mayfly Larvae of Wisconsin—Chapter 8 Labiobaetis dardanus (McDunnough), 1923 (Figs. 84 and 85) Taxonomic History: Baetis dardanus molar regions of the right mandible 1L, St. Croix R., Nevers Landing, McDunnough, 1923 (orig.); Baetis (Fig. 83i). 1 mi. S. of Wolf Creek, 45o32’10”N o elachistus Burks, 1953 (syn.); Previous Wisconsin Records: Lillie 92 43’25”W, VII-13-2011, THK (THK); Labiobaetis dardanus (McDunnough), (1995), misidentified as Baetis caelestis RICHLAND: Wisconsin R., Gotham, 1923 (curr. comb. sensu McCafferty and Allen & Murvosh (Randolph and IX-28-1986, R. A. Lillie, (UW); SAUK: Waltz 1995); Pseudocloeon dardanum McCafferty 1998). Bergman and 1L, Wisconsin R., St. Rd. 130/133 o o (McDunnough), 1923 (comb.). Hilsenhoff (1978a) reported and bridge, 43 9’55”N 90 11’34”W, VII-26- Larval Descriptions: Soluk 1981, as described larvae of B. propinquus 2011, THK (THK). Baetis dardanus. from Wisconsin. These larvae were Status: Labiobaetis dardanus is listed Larval Habitus: Bergman and corrected to B. longipalpus by Morihara as a Species of Special Concern on Hilsenhoff (1978a), as Baetis and McCafferty (1979a). Soluk (1981) the Wisconsin Department of Natural propinquus; Soluk (1981), as B. subsequently corrected the same larvae Resources Natural Heritage Working dardanus. to B. dardanus. List, as Pseudocloeon dardanum (Anonymous 2014b). Determination: Identification of New County Records: BURNETT: L. dardanus larvae is Moderately 1L, St. Croix R., canoe landing on S. Biological Information: Very Difficult. Field determination is Markville Rd., 1000 ft. W. of St. Rd. 35 little biological information has o o virtually impossible, as dissection bridge, 46 4’26”N 92 15’3”W, VII-13- been published for L. dardanus. In of mouthparts is required. The 2011, THK (THK); COLUMBIA: 1L, Wisconsin, Iowa, and Nebraska, I have species structurally is most similar Wisconsin R., Levee Rd., Pine Island found it most commonly in medium to o o to L. ephippiatus, but has a rounded Wildl. Area, 43 32’35”N 89 34’57”W, large rivers. protuberance between the incisor and VII-26-2011, THK (THK); POLK:

Figure 84. Labiobaetis dardanus, larva.

Figure 85. Wisconsin records of Labiobaetis dardanus.

Baetidae 79 Labiobaetis ephippiatus (Traver), 1935 (Figs. 86 and 87) Taxonomic History: Acentrella of more mature larvae. Though these Wildl. Area, 43o32’35”N 89o34’57”W, ephippiatus (Traver), 1935 (comb.); notes on the coloration of L. ephippiatus VII-26-2011, THK (THK); GREEN: Baetis ephippiatus Traver, 1935 (orig.); may assist in sorting, dissection of 2L, Sugar R., Co. Rd. C, 0.2 mi. E. of Labiobaetis ephippiatus (Traver), 1935 mouthparts is required for reliable Attica, 42o46’12”N 89o28’35”W, VIII- (curr. comb. sensu McCafferty and identification. The right mandible bears 8-2011, THK, E. Wolf, and C. Brown Waltz 1995); Pseudocloeon ephippiatum a more sharp and angular projection (THK); JACKSON: 2L, Black R., River (Traver), 1935 (comb.). between the incisor and molar Rd. Canoe Launch, VII-11-2013, K. Larval Descriptions: Berner (1940), regions (Fig. 83g) than in larvae of L. L. Schmude (UWS); LA CROSSE: as Acentrella ephippiatus; Morihara and dardanus (Fig. 83i). The angle of view is 2L, Black R., St. Rd. 35, N. side of Rd., McCafferty (1979a,b), as Baetis important, being best from an awkward, VII-10-2013, K. L. Schmude (UWS); ephippiatus. unnatural angle. The mandible often PEPIN: 1L, Chippewa R., St. Rd. 35, will not lie in a suitable position in a W. side, VII-10-2013, K. L. Schmude Determination: Identification of permanent slide mount, making a wet (UWS). L. ephippiatus larvae is Moderately mount more desirable. The dissected Difficult. Mature larvae taken from the Biological Information: Labiobaetis mandible should be retained with the ephippiatus is known from a variety of Sugar River in extreme northern Illinois specimen in a microvial. were darkly colored, as shown in Fig. stream sizes in Kansas, including small, 86. Slightly less mature larvae have Previous Wisconsin Records: None, intermittent streams to large rivers abdominal terga II and V–VI distinctly with the first Wisconsin records given (Liechti 1980). Berner and Pescador darker than other terga. Abdominal below. Closest records of L. ephippiatus (1988) described the habitat of this sterna I–VII each has a dark, median were from northwestern Indiana species in Florida as sand-bottomed spot on anterior margin, suggestive (Randolph and McCafferty 1998) and stream margins, where larvae cling to of Plauditus punctiventris. In very in the Sugar River in extreme northern vegetation. It also has been reported young larvae, the only remaining dark Illinois (Klubertanz and Hess 2001). from woody debris (Berner 1950; coloration on the terga is a median spot It is likely that other populations in Lager 1985). on abdominal tergum II, suggestive Wisconsin have been overlooked. of Paracloeodes minutus, while the New Wisconsin Records: COLUMBIA: sternal markings are similar to those 1L, Wisconsin R., Levee Rd., Pine Island

Figure 86. Labiobaetis ephippiatus, larva.

Figure 87. Wisconsin records of Labiobaetis ephippiatus.

80 Mayfly Larvae of Wisconsin—Chapter 8 Labiobaetis frondalis (McDunnough), 1925 (Figs. 88 and 89) Taxonomic History: Baetis australis a slide mount of the labrum is made. Biological Information: Labiobaetis Traver, 1932 (syn.); Baetis baeticatus Dorsal submarginal setae of the labrum frondalis is a common species of Burks, 1953 (syn.); Baetis frondalis are only slightly spatulate in L. frondalis depositional areas and backwaters of McDunnough, 1925 (orig.); Labiobaetis (Fig. 83h) and easily misinterpreted. In small streams and rivers, where silt or frondalis (McDunnough), 1925 L. frondalis, these setae are more evenly sand is on the bottom (Berner 1950; (curr. comb. sensu McCafferty and spaced than in larvae of L. propinquus Bergman and Hilsenhoff 1978a; Berner Waltz 1995); Pseudocloeon frondale (Fig. 8k). and Pescador 1988). It is widespread in (McDunnough), 1925 (comb.). Previous Wisconsin Records: Wisconsin and is second in abundance Larval Descriptions and Habitus: Hilsenhoff et al. (1972), as Baetis in the genus to L. propinquus. Burian Bergman and Hilsenhoff (1978a) and frondalis; Randolph and McCafferty and Gibbs (1991) reported L. frondalis Morihara and McCafferty (1979a,b), (1998). as most common on submerged, long- both as Baetis frondalis. leafed vegetation and on the stems and New County Records: SAUK: 1L, Otter leaves of rushes and sedges. Determination: Identification ofL. Crk., St. Rd. 60, 2.5 mi. W. of Sauk City, o o frondalis larvae is Moderately Difficult. 43 16’16”N 89 47’5”W, VII-26-2011, They are easily misidentified as the THK (THK). more common L. propinquus unless

Figure 88. Labiobaetis frondalis, larva.

Figure 89. Wisconsin records of Labiobaetis frondalis.

Baetidae 81 Labiobaetis longipalpus (Morihara & McCafferty), 1979 (Figs. 90 and 91) Taxonomic History: Baetis longipalpus genus that readily can be identified the Wisconsin Department of Natural Morihara and McCafferty, 1979 (orig.); without slide mounts. Some larvae Resources Natural Heritage Working Labiobaetis longipalpus (Morihara of L. longipalpus are similar in dorsal List, as Pseudocloeon longipalpus and McCafferty), 1979 (curr. comb. coloration to Acerpenna macdunnoughi. (Anonymous 2014b). It is known in sensu McCafferty and Waltz 1995); Previous Wisconsin Records: the state only from the Wisconsin and Pseudocloeon longipalpus (Morihara Morihara and McCafferty (1979b), Black Rivers. and McCafferty), 1979 (comb.). as Baetis longipalpus; Randolph and Biological Information: Labiobaetis Larval Description and Habitus: McCafferty (1998). Bergman and longipalpus occurs in larger rivers, in Morihara and McCafferty (1979a,b), Hilsenhoff (1978a) reported and stronger currents, and in deeper waters both as Baetis longipalpus. described larvae of B. propinquus than other members of the genus Determination: Identification of L. from Wisconsin. These larvae were (Morihara and McCafferty 1979b; Lillie longipalpus larvae is Slightly Difficult. corrected to B. longipalpus by Morihara and Hilsenhoff 1992; Klubertanz 1995). They have the combination of dense and McCafferty (1979a). Soluk (1981) Klubertanz (1995) reported it from setation of the labrum (Fig. 83a), corrected the same larvae to large stones and logs in deep riffles in narrow shape of the labial palpi (Fig. B. dardanus. Iowa, while Liechti (1980) reported it 83b), and distinct dorsal coloration. Status: Labiobaetis longipalpus is listed from various debris piles in a sandy The species is the only member of the as a Species of Special Concern on river in Kansas.

Figure 90. Labiobaetis longipalpus, larva.

Figure 91. Wisconsin records of Labiobaetis longipalpus.

82 Mayfly Larvae of Wisconsin—Chapter 8 Labiobaetis propinquus (Walsh), 1863 (Figs. 92 and 93) Taxonomic History: Acentrella Previous Wisconsin Records: Shapas Rd., 2.5 mi. N. of Brill, 45o38’21”N propinquus (Walsh), 1863 (comb.); and Hilsenhoff (1976), as Baetis 91o40’27”W, VII-15-2011, THK (THK); Baetis propinquus (Walsh), 1863 spinosus; Bergman and Hilsenhoff 2L, Hay Crk., Hamilton Rd., 0.6 mi. (comb.); Baetis spinosus McDunnough, (1978a), as B. spinosus; Lillie and NW. of Springbrook, 45o57’27”N 1925 (syn.); Cloe propinqua Walsh, 1863 Hilsenhoff (1992), as B. propinquus; 91o41’29”W, VII-15-2011, THK (THK); (renam.); Cloe vicina Walsh, 1862 (hom. Hilsenhoff (1996); Randolph and 1L, Namekagon R., Groat Landing, C. vicina Hagen, 1861); Labiobaetis McCafferty (1998). Bergman and Brickman Rd., 7 mi. WSW. of Hayward, propinquus (Walsh), 1863 (curr. comb. Hilsenhoff (1978a) reported and 45o59’45”N 91o38’6”W, VII-15-2011, sensu McCafferty and Waltz 1995); described larvae of B. propinquus THK (THK); 11L, Namekagon R., Pseudocloeon propinquum (Walsh), from Wisconsin. These larvae were Stinnett Landing on Stinnett Landing 1863 (comb.). corrected to B. longipalpus by Morihara Rd., 45o59’9”N 91o35’34”W, VII-15- Larval Descriptions and Habitus: and McCafferty (1979a). Soluk (1981) 2011, THK (THK); WINNEBAGO: 1L, Clemens (1913, 1915c), as Baetis corrected the same larvae to B. Fish Trap Pond (likely in Rush Crk.), propinquus; Bergman and Hilsenhoff dardanus. T18NR14E S36, IX-17-2007, J. Meyer (1978a), as B. spinosus; Morihara and New County Records: BARRON: 2L, (UWO). McCafferty (1979a,b), as B. propinquus. Brill R., 29th Ave., 1.5 mi. N. of Brill, Biological Information: Lillie and o o Determination: Identification of 45 37’28”N 91 40’38”W, VII-15-2011, Hilsenhoff (1992) found larvae of L. L. propinquus larvae is Moderately THK (THK); 1L, Red Cedar R., St. Rd. propinquus abundant in the lower o Difficult. They are larger and more 48, 2 mi. NE. of Rice Lake, 45 31’49”N Wisconsin River, on a variety of o robust than most stream baetids, but 91 42’11”W, VII-15-2011, THK (THK); substrates in shorelines and shallows. are not easily separated from other WALWORTH: 1L, Turtle Crk., Klug Likewise, I have found it as the species in the genus. Preparation Rd. (formerly Pounder Rd.), 2 mi. NW. dominant baetid at a number of sites. of slide mounts of mouthparts is of Delavan, VIII-4-2000, THK (THK); Bergman and Hilsenhoff (1978a), required for proper identification. In 2L, Turtle Crk., Klug Rd. (formerly however, considered it uncommon L. propinquus, the dorsal submarginal Pounder Rd.), 2 mi. NW. of Delavan, overall in Wisconsin. It can be setae of the labrum are fewer in number VI-23-2011, THK, C. Brown, and E. associated with plants, logs, and rubble, than in L. frondalis, with clear and Wolf (THK); 4L, Turtle Crk., School particularly in stream backwaters consistent submedian gaps (Fig. 8k). Section Rd., T2NR15E S15, VI-23-2011, (Bergman and Hilsenhoff 1978a; Burian THK, C. Brown, and E. Wolf (THK); and Gibbs 1991). WASHBURN: 1L, Brill R., Bridge

Figure 92. Labiobaetis propinquus, larva.

Figure 93. Wisconsin records of Labiobaetis propinquus.

Baetidae 83 Neocloeon Anafroptilum. Centroptilum is now all Anafroptilum. In Neocloeon, the Comments: The two recognized restricted to Old World species. third segment of the maxillary palpi species of North American Neocloeon Determination: Identification of is long, sharply tipped, and weakly most recently were included in Neocloeon larvae is Slightly Difficult separated from the second segment. In Centroptilum. Kluge (2011) and Jacobus for the genus and Difficult for the contrast to most Wisconsin species of and Wiersema (2014) reassigned species within the genus. Larvae of Anafroptilum, the abdominal terga of all of the North American species the two North American species lack Neocloeon have spines along the lateral of Centroptilum to Neocloeon and metathoracic wingpads, unlike almost margin that are sufficiently robust to also suggest Procloeon. Key to the Species of Neocloeon 1. Each femur of fresh specimens with a dark band extending from dorsal margin at two-thirds length (Fig. 94a); gill tracheation interrupted by a white band at two-thirds length (Fig. 94b); males never present...... N. triangulifer Each femur unbanded or with an indistinctly shaded band extending from dorsal margin at two-thirds length; gill tracheation uninterrupted in distal half of gills; males usually present in populations...... N. alamance

a g h b

Figure 94. Neocloeon (Baetidae). a, N. triangulifer, hind femur (posterior); b, N. triangulifer, gill.

84 Mayfly Larvae of Wisconsin—Chapter 8 Neocloeon alamance Traver, 1932 (Fig. 95) Taxonomic History: Centroptilum Previous Wisconsin Records: alamance (Traver), 1932 (comb.); Hilsenhoff et al. (1972); Randolph and Cloeon alamance (Traver), 1932 McCafferty (1998), as Centroptilum (comb.); Neocloeon alamance Traver, alamance. 1932 (orig., curr. comb. Jacobus and Status: Published records of N. Wiersema 2014). alamance are only from Florence Larval Description: Traver (1932a); and Forest Counties in northeastern Funk et al. (2006), as Centroptilum Wisconsin. There are unverified reports alamance. from the Wisconsin Department of Larval Habitus: Traver (1932a, 1932b, Natural Resources that this species also 1935). occurs in several other far northern counties of the state. Determination: Identification of N. alamance larvae is Difficult. Faded Biological Information: In contrast to N. triangulifer, parthenogenesis Figure 95. Wisconsin records of specimens can be particularly hard to Neocloeon alamance. identify, as no structural characters is not obligatory and males of N. separate N. alamance from N. alamance may be present within a given triangulifer (Jacobus and Wiersema population. There are no previously 2014). published details regarding the habitat associations of this species.

Neocloeon triangulifer (McDunnough), 1931 (Figs. 96 and 97) Taxonomic History: Centroptilum than similar marks found on larvae of (blackwing) larvae. Interestingly, all sp. 1 McCafferty and Davis, 1992 Procloeon viridoculare (Fig. 111f), P. larvae of this form I have observed (syn.); Centroptilum triangulifer fragile, or Pseudocentroptiloides. The lack lateral spines on abdominal terga (McDunnough), 1931 (comb.); Cloeon remaining sterna of these specimens II and III. Such larvae have been triangulifer McDunnough, 1931 (orig.); are entirely white or have barely evident found in both northern (Lincoln Neocloeon triangulifer (McDunnough), speckles in posterior half of each and Burnett Counties) and southern 1931 (curr. comb., Jacobus and segment. Such specimens are consistent (Sauk) Wisconsin. Both of these forms Wiersema 2014). in having lateral spines on the third tentatively identified as N. triangulifer Larval Description: Funk et al. (2006), abdominal tergum and usually have have distinct bands near the distal as Centroptilum triangulifer. at least one such spine on the second ends of the femora in contrast to N. tergum. In much rarer specimens, alamance. No other differences between Determination: Identification of the abdominal sterna are much more these forms have been found, so it is N. triangulifer larvae is Difficult. patterned throughout. They lack the not known whether they are separate They are very similar to larvae of N. transverse mark on the anterior margin species or simply variations of alamance. Though color differences of the ninth segment. Instead, they N. triangulifer. traditionally have been used to separate have well-defined submedial spots in the species, there are no known Previous Wisconsin Records: the anterior quarter of each sternum McCafferty et al. (2004). morphological differences (Jacobus and many speckles throughout each and Wiersema 2014). Separation of sternum. This pattern is suggestive of New County Records: LINCOLN: the two species usually requires fresh, Anafroptilum sp. A, except for having 1L, Devil Crk., upstream 20 m o unfaded specimens. In most Wisconsin more circular submedian spots on from Highland Dr., 45.13443 N o specimens I have examined, the the sterna and, of course, lacking 89.84708 W, X-6-2011, H. Yang anterior margin of the ninth abdominal metathoracic wingpads. The pattern (UWSP); MARATHON: 1L, Silver nd sternum has a transverse, dark band. occurs in both immature and mature Crk., upstream 17 m from 72 Ave., The band is much less well-defined 45.07773oN 89.72725oW, X-5-2011,

Baetidae 85 H. Yang (UWSP); ROCK: 2L, Turtle Haymeadow Crk., X-17-1968 (UW); to that of species of Anafroptilum. Crk., Smith Rd., between Shopiere 1L, Wisconsin R., upstream 50 m from Burian and Gibbs (1991) described its and Tiffany, VII-27-1999, THK and Co. Rd. K, 46.04779oN 89.26578oW, habitat as emergent vegetation along C. Hess (THK); RUSK: 2L, Chippewa X-17-2011, H. Yang (THK). the shoreline of second- to fourth-order R., Co. Rd. D, T33NR7W S33, VI-23- Status: Neocloeon triangulifer is listed streams. Neocloeon triangulifer is an 1998 (WiDNR); 1L, Hay Crk., Singer as a Species of Special Concern on obligatory parthenogenetic species that o Rd., site “Chipr 7220”, 45.479244 N the Wisconsin Department of Natural is very closely related to the sexually o 91.380158 W, Summer 2012, K. L. Resources Natural Heritage Working reproducing N. alamance (McCafferty Schmude (UWS); SAUK: 1L, Otter List (Anonymous 2014b). It is the most et al. 2004). Funk et al. (2006) found Crk., Baxter’s Hollow, Stone’s Pocket widely distributed and most commonly both genetic and morphological Rd., VII-31-2007, THK (THK); encountered member of the genus in differences between the two species, SAWYER: 1L, Flambeau R., Hervas, the state. validating their status as separate T37N R4W S35, VI-19-1997 (WiDNR); species. 2L, Flambeau R., Oxbo Rd., 39NR3W Biological Information: The biology S14, VI-18-1997 (WiDNR); VILAS: 1L, of N. triangulifer apparently is similar

Figure 96. Neocloeon triangulifer, larva.

Figure 97. Wisconsin records of Neocloeon triangulifer.

86 Mayfly Larvae of Wisconsin—Chapter 8 Paracloeodes The remaining species are from South America (Kluge 2014). Comments: There are three species of Paracloeodes in North America Determination: Identification of (Anonymous 2014a). Only one of Paracloeodes larvae in Wisconsin is them is known from the Midwest. Fairly Easy.

Paracloeodes minutus (Daggy), 1945 (Figs. 98 and 99) Taxonomic History: Paracloeodes 44.819648oN 91.363869oW, IX-29- the species was uncommonly collected abditus Day, 1955 (syn.); Paracloeodes 2009, M. Hazuga (THK); GRANT: because of size, not because of its rarity. minutus (Daggy), 1945 (curr. comb., 2L, Wisconsin R., Woodman, 3–4 ft. Biological Information: The very Edmunds et al. 1976); Pseudocloeon sand, moderate flow, VI-20-1986, R. small larvae of P. minutus are not easily minutum Daggy, 1945 (orig.). A. Lillie (UW); IOWA: 1L, Wiscon- collected, though a significant amount Larval Description: Daggy (1945), as sin R., Co. Rd. C, 2.2 mi. NNE. of of biological information is available o o Pseudocloeon minutum. Spring Green, 43 8’41”N 90 3’13”W, for the species. They mostly occur in VIII-8-2011, THK, E. Wolf, and C. Larval Habitus: Lillie (1995). warm-water streams (Edmunds et Brown (THK); MARINETTE: 1L, al. 1976). Mature larvae can occur in o o Determination: Identification of Para- Pike R., 45.496827 N 87.982493 W, large numbers in extremely shallow, cloeodes minutus larvae is Fairly Easy. VIII-12-2009 (THK); ROCK: 22L, silted pools and puddles of water along Misidentification most likely is as a very Turtle Crk., Shopiere, VII-13-1999, shorelines and floodwaters (Edmunds small Procloeon, Anafroptilum, Neoclo- THK (THK); SAUK: 1L, Wisconsin et al. 1976; Lillie and Hilsenhoff 1992; o eon, Pseudocentroptiloides, or Apobaetis. R., St. Rd. 130/133 bridge, 43 9’55”N McCafferty et al. 2003a). Apparently, o Careful use of the key is recommend- 90 11’34”W, VII-26-2011, THK (THK); larvae occupy sandbars in deeper water ed. Larvae of Paracloeodes minutus, in WAUPACA: 3L, Little Wolf R., Bridge during most of their development and addition to the characters used in the Road, upstream along bridge riprap, only migrate to shallows when mature. o o key, usually have a distinctive, dark 44.4946065 N 88.8999065 W, IX-20- In southeastern Nebraska streams and ring around a pale area on the second 2012, J. Riebe (UWSP). rivers, I have observed large numbers abdominal tergum. Status: Paracloeodes minutus is listed of mature P. minutus larvae in extreme- Previous Wisconsin Records: Lillie as a Species of Special Concern on ly shallow water and isolated puddles and Hilsenhoff (1992); Lillie (1995). the Wisconsin Department of Natural along the shoreline. Despite the larvae being excellent swimmers, a shallow New County Records: ASHLAND: Resources Natural Heritage Working pan could be used to scoop up large Marengo R., Government Rd., IX-9- List (Anonymous 2014b). Lillie (1995) numbers of individuals in a short time. 2009, K. L. Schmude (UWS); EAU recommended that it be considered CLAIRE: 10L (including blackwing), for conservation efforts. Randolph and Eau Claire R., adjacent to Co. Rd. Q, McCafferty (1998) believed, rather, that

Figure 98. Paracloeodes minutus, larva.

Figure 99. Wisconsin records of Paracloeodes minutus.

Baetidae 87 Plauditus unknown as larvae, and the number of identification of the genus, and very recently described species, there Moderately Easy to Problematic for Comments: The species currently likely are many misidentified specimens the species within the genus. placed in Plauditus have been the in various collections (Wiersema subject of numerous taxonomic changes Larval Keys: Traver (1935) and 1999a). There are ten recognized and historically have been placed in Burks (1953), both as Pseudocloeon; species, all from North America (Kluge various combinations in a number of Hilsenhoff (1982), as Baetis and 2014), with only four known from genera, including Acentrella, Barbaetis, Pseudocloeon. Wisconsin. Baetis, Cloeon, and Pseudocloeon. Because of the difficulty of identifying Determination: Identification of Plauditus larvae, the number of species Plauditus larvae is Fairly Easy for

Key to the Species of Plauditus (P. elliotti and P. veteris not keyed) 1. Antennae of mature larvae equal to or shorter than one and a half times the length of head capsule (Fig. 100a); labial palpus with broadened third segment (Fig. 100b); protarsal claw with dorsal margin relatively straight, with a gently curved tip (Fig. 100c); tergum and sternum of either V or VII darkened in contrast to other segments (Fig. 101); males and females similarly patterned...... 2 Antennae of mature larvae usually at least two times longer than length of head capsule; labial palpus with third segment appearing truncate but not broadened (Fig. 20m); protarsal claw with dorsal margin more distinctly curved from base to tip (Fig. 20j); terga and sterna variously colored, usually with all terga uniformly colored (females) or with three or more segments darker than others (males)...... 3 2. Antennae distinctly longer (usually at least one and a half times) than head capsule; tergum and sternum V similar in darkness to other segments and often not as dark as VII; pro- and mesofemora each with a short and long, dark mark on anterior surface in fresh specimens (Fig. 100d); tergum and sternum IX usually not darkened; abdominal sterna usually with dark, medial mark in intersegmental spaces (similar to P. punctiventris)...... P. gloveri Antennal length subequal to length of head capsule (Fig. 100a); tergum and sternum V usually darker than IV, VI, and VII (Fig. 101); pro- and mesofemora not marked as above, each usually with a dark crossband near base in fresh specimens; tergum and sternum IX sometimes slightly darker than other segments; abdominal sterna without a dark, medial mark in each intersegmental space...... P. cestus 3. At least some abdominal sterna with a median dark spot or dash along posterior margins, sometimes extending into the intersegmental membranes (Fig. 100e)...... P. punctiventris / P. virilis Abdominal sterna with pairs of submedian spots or streaks, but without median posterior spots; a series of unfaded specimens recommended ...... 4 4. Each caudal filament without a dark band at midlength...... P. cingulatus Each caudal filament with a dark band at midlength; male larva with terga V–VII strikingly darker than other segments (Fig. 105); female larva with terga uniformly colored (Fig. 106)...... P. dubius

88 Mayfly Larvae of Wisconsin—Chapter 8 a b

c

d e

Figure 100. Plauditus (Baetidae). a, P. cestus, head (anterior); b, P. cestus, labium (ventral); c, P. cestus, front claw; d, P. gloveri, front leg (anterior); e, P. punctiventris, abdominal sterna.

Plauditus cestus (Provonsha & McCafferty), 1982 (Figs. 101 and 102) Taxonomic History: Barbaetis cestus abdominal segment usually is VII. In 44.65431oN 88.60595oW, VI-3-1999, (Provonsha and McCafferty), 1982 most P. cestu s , both the tergum and K. L. Schmude, C. Brennan, and (comb.); Plauditus cestus (Provonsha the sternum of the fifth abdominal J. Tanck (UWS). and McCafferty), 1982 (curr. comb., segment contrast strongly with adjacent Status: Plauditus cestus is listed as Lugo-Ortiz and McCafferty 1998a); segments (Fig. 101). Structurally, P. a Species of Special Concern on the Pseudocloeon cestum Provonsha and cestus is most similar to P. gloveri. Wisconsin Department of Natural McCafferty, 1982 (orig.). Intraspecific and interspecific variability Resources Natural Heritage Working Larval Descriptions: Provonsha and of these two species was covered in List (Anonymous 2014b). It is known McCafferty (1982), as Pseudocloeon detail by McCafferty and Jacobus only from scattered locations in the cestum; Lugo-Ortiz and McCafferty (2001). northern half of the state. (1998b); McCafferty and Jacobus Previous Wisconsin Records: Biological Information: Plauditus (2001). McCafferty and Jacobus (2001). cestus is a very small species occurring Larval Habitus: Provonsha and New County Record: ASHLAND: in clean streams and rivers with pea- McCafferty (1982), as Pseudocloeon Marengo R., Government Rd., IX- sized gravel bottoms (Provonsha and cestum. 9-2009, K. L. Schmude (UWS); McCafferty 1982; Webb et al. 2004). Determination: Identification of BURNETT: 2L, St. Croix R., Nelson, In Wisconsin, it is known from both Plauditus cestus larvae is Moderately SW. of Danbury, Summer 1996 small and large rivers. Because of their Easy for fresh specimens. Though (WiDNR); 1L, St. Croix R., Sand size, larvae are often overlooked if mature larvae of Plauditus cestus are Rock Cliffs, 5 mi. NW. of Grantsburg, fine-meshed nets are not used (Lugo- quite small, the distinctive abdominal T38NR19W S7, Summer 1996 Ortiz and McCafferty 1998b). Little is coloration usually is a reliable field (WiDNR); SHAWANO: 6L in two vials, known regarding the phenology of this o mark. In male larvae of P. dubius, Mill Crk., Willow Crk. Rd., 44.75561 N species in Wisconsin. All of the adults o abdominal terga IV through VI usually 88.75651 W, VI-6-2000, K. L. Schmude, of P. cestus that I have examined from are darker than other segments (Fig. C. Brennan, and J. Denninger (UWS); Wisconsin were taken in June. 105). In P. gloveri, the only darkened WAUPACA: 2L, Wolf R., River Rd.,

Baetidae 89 Figure 101. Plauditus cestus, larva.

Figure 102. Wisconsin records of Plauditus cestus.

Plauditus cingulatus (McDunnough), 1931 (Figs. 103 and 104) Taxonomic History: Baetis cinctutus Determination: Identification of P. Status: Plauditus cingulatus is listed McCafferty and Waltz, 1990 (syn.), cingulatus larvae is Moderately Easy as a Species of Special Concern on Plauditus cinctutus (McCafferty and for unfaded, intact specimens, but the Wisconsin Department of Natural Waltz), 1990 (syn. comb.); Plauditus Moderately Difficult for specimens Resources Natural Heritage Working cingulatus (McDunnough), 1931 (curr. with broken caudal filaments. Faded List (Anonymous 2014b). It likely is the comb., McCafferty 1999); Pseudocloeon material of P. cingulatus may be least common member of the genus in cingulatum McDunnough, 1931 (orig.). inseparable from P. dubius. the state. In 1925, McDunnough described Previous Wisconsin Records: Biological Information: Plauditus Baetis cingulatus, which later was Hilsenhoff et al. (1972), as Baetis cingulatus was reported from erosional synonymized with Baetis flavistriga. cingulatus; Randolph and McCafferty reaches of first- to third-order streams In 1931, McDunnough applied the (1998), as B. cinctutus. (Burian and Gibbs 1991), though the similar name Pseudocloeon cingulatum, New County Records: POLK: 1L, St. St. Croix River record above suggests a which is the correct origin of Plauditus tolerance of larger rivers. cingulatus (McDunnough 1931a). Croix R., Nevers Landing, near Wolf Creek, Summer 1996 (WiDNR). Larval Description: Leonard and Leonard (1962).

Figure 103. Plauditus cingulatus, larva.

Figure 104. Wisconsin records of Plauditus cingulatus.

90 Mayfly Larvae of Wisconsin—Chapter 8 (Walsh), 1862 (Figs. 105–107) Taxonomic History: Baetis dubius Previous Wisconsin Records: on Belding Rd. in Shopiere, T1NR13E (Walsh), 1862 (comb.); Cloe dubia Hilsenhoff (1972), Shapas and S3, VI-6-2011, THK, C. Brown, and E. Walsh, 1862 (orig.); Cloeon chlorops Hilsenhoff (1976), and Hilsenhoff Wolf (THK); 2L, Yahara R., Murwin Pk. McDunnough, 1923 (syn.); Cloeon (1982), all as Pseudocloeon dubium; in Fulton, VII-7-2011, THK, E. Wolf, dubium (Walsh), 1862 (comb.); Randolph and McCafferty (1998), as and C. Brown (THK); RUSK: 15L in Plauditus dubius (Walsh), 1862 Baetis dubius. three vials (including blackwing), N. (curr. comb., Lugo-Ortiz and New County Records: DUNN: 1L, Fork Chippewa R., Bruce, T34NR7W McCafferty 1998a); Pseudocloeon Chippewa R., 640th St. Landing, S5, VI-23-1998 (WiDNR); SAWYER: chlorops (McDunnough), 1923 (syn.); VII-9-2013, K. L. Schmude (UWS); 30L in three vials, Chippewa R., Pseudocloeon dubium (Walsh), 1862 JACKSON: 1L, Black R., River Rd. Town Line Rd., T37NR7W S35, VI- (comb.). Canoe Launch, VII-11-2013, K. L. 23-1998 (WiDNR); WASHBURN: Larval Description: Clemens (1913, Schmude (UWS); MARINETTE: 2L, 6L, Namekagon R., Groat Landing, 1915c), as Cloeon dubium; Burks Menominee R., Co. Rd. Z, T36NR22E Brickman Rd., 7 mi. WSW. of Hayward, o o (1953), as Pseudocloeon dubium. S20, VI-25-1996 (WiDNR); PEPIN: 2L, 45 59’45”N 91 38’6”W, VII-15-2011, Chippewa R., Ella Boat Landing, VII- THK (THK); 1L, Namekagon R., Co. Larval Habitus: Clemens (1913), as Rd. K, T40NR12W S18, VI-24-1998 Cloeon dubium. 9-2013, K. L. Schmude (UWS); POLK: 1L, St. Croix R., Sunrise, VI-10-1996 (WiDNR). Determination: Identification of (WiDNR); ROCK: 3L in two vials, Biological Information: Burian and Plauditus dubius larvae is Moderately Turtle Crk., Carver’s Rock Rd., VI-1- Gibbs (1991) described the habitat Easy. Larvae are sexually dimorphic, 2005 and VII-20-2007, THK (THK); of Plauditus dubius as erosional and with males (Fig. 105) having more Turtle Crk., Shopiere, VII-20-2007, transitional reaches of second- and third- contrasting abdominal terga. Females THK (THK); 3L, Turtle Crk., Lathers order streams. In Wisconsin, though, the (Fig. 106) can be confused with Rd., 1 mi. WSW. of Shopiere, T2NR13E species also is known from a number of Acentrella turbida. Faded specimens S9, THK, C. Brown, and E. Wolf medium to large rivers, including the St. may be inseparable from P. cingulatus (THK); 6L, Turtle Crk., Sweet Allyn Pk. Croix, Chippewa, and Menominee Rivers. and P. punctiventris.

Figure 105. Plauditus dubius, male larva.

Figure 107. Wisconsin records of Plauditus dubius.

Figure 106. Plauditus dubius, female larva.

Baetidae 91 Plauditus elliotti (Daggy), 1945 Taxonomic History: Baetis elliotti Determination: Identification of adults collected from the Mississippi (Daggy), 1945 (comb.); Plauditus Plauditus elliotti larvae is Problematic. River in Fridley, Minnesota (north of elliotti (Daggy), 1945 (curr. comb., The species has not been formally Minneapolis). Lugo-Ortiz and McCafferty 1998a); described as larvae. Biological Information: No accounts Pseudocloeon elliotti Daggy, 1945 Previous Wisconsin Records: None. of the biology of this species have been (orig.); Pseudocloeon ida Daggy, 1945 Plauditus elliotti was originally published. (syn.). described by Daggy (1945) based upon

Plauditus gloveri McCafferty & Waltz, 1998 (Fig. 108) Larval Descriptions: McCafferty and Previous Wisconsin Records: None. the absence of records from Wisconsin Waltz (1998); McCafferty and Jacobus Closest records of P. gloveri are from and neighboring states likely is because (2001). south-central Indiana (Jacobus and of being overlooked. It is expected in Larval Habitus: McCafferty and Waltz McCafferty 2006). Since the species Wisconsin. (1998). has a fairly widespread distribution, Biological Information: No accounts from the southeastern United States Determination: Identification of P. of the biology of this species have been to Manitoba (McCafferty and Waltz published. gloveri larvae is Fairly Easy. Faded 1998; Jacobus and McCafferty specimens may be difficult to separate 2001; McCafferty and Jacobus 2001; from other species in the genus. Adults McCafferty et al. 2004; Webb et al. of P. gloveri have not been formally 2004; Jacobus and McCafferty 2006), described.

Figure 108. Plauditus gloveri, larva.

92 Mayfly Larvae of Wisconsin—Chapter 8 Plauditus punctiventris (McDunnough), 1923 (Figs. 109 and 110) Taxonomic History: Baetis I am not aware of reliable characters revalidated. Many of the specimens in punctiventris (McDunnough), 1923 to separate larvae of P. punctiventris the University of Wisconsin collection (comb.); Baetis sp. 1 McCafferty from P. virilis, and I have not examined previously identified as P. punctiventris and Davis, 1992 (syn.); Cloeon confirmed, reared specimens of P. are now corrected to I. anoka. The punctiventris McDunnough, 1923 virilis. Specimens in the Purdue confirmed and new county records (orig.); Plauditus punctiventris Entomological Research Collection of P. punctiventris listed below do not (McDunnough), 1923 (curr. comb., labeled as P. virilis (Bartholomew eliminate the possibility that some Lugo-Ortiz and McCafferty 1998a); Co., IN, IV-19-2005) have a ventral could actually be P. virilis. Pseudocloeon myrsum Burks, 1953 spot along the posterior margin of Confirmed County Records: (syn.); Pseudocloeon punctiventris each sternum (and intersegmental BARRON: Bear Crk. (UWS); (McDunnough), 1923 (comb.). membrane) as in P. punctiventris. Ide BURNETT: St. Croix R. (WiDNR); Larval Descriptions: Burks (1953), as (1937) made no mention of these marks CLARK: Cunningham Crk. (UWS); Pseudocloeon myrsum and P. punctiventris. in his description of P. virilis, so I am POLK: St. Croix R. (THK); PRICE: S. unsure of the identity of the Indiana Determination: Identification of Fork Flambeau R. (WiDNR); ROCK: specimens. Larvae of P. punctiventris, Marsh Crk. (UWS), Turtle Crk. (THK); Plauditus punctiventris larvae is P. virilis, and P. dubius are sexually Difficult, even for fresh specimens. RUSK: N. Fork Chippewa R. (WiDNR); dimorphic, with males having more WASHBURN: Bean Brk. (THK). Larvae are easily confused with other contrasting abdominal terga than species, including P. dubius, P. gloveri, females (as in Fig. 109). Structural New County Records: MARINETTE: P. virilis, and Iswaeon anoka. Larvae of characters to separate these three 2L, Menominee R., Mine Rd., I. anoka can have a dark spot centrally species as larvae are lacking. T27NR21E S25, VI-24-1997, R. A. Lillie located on each abdominal sternum (WiDNR). Previous Wisconsin records: (Fig. 20h), rather than between Biological Information: Burian and segments, and always have more Hilsenhoff et al. (1972), as Pseudocloeon punctiventris; Shapas and Hilsenhoff Gibbs (1991) described the habitat of robust tibiae (Fig. 20g) than Plauditus. P. punctiventris as second- and third- Many collections have specimens of I. (1972), as P. punctiventris; Hilsenhoff (1982), as P. punctiventris; Randolph order streams. Field work is needed to anoka misidentified as P. punctiventris, clarify the habitat and tolerance of this to which it formerly was a junior and McCafferty (1998), as Baetis punctiventris. All Midwest records species independent of Iswaeon anoka. synonym. In P. punctiventris, each Taxonomic work, likely including abdominal sternum has a dark medial of this species prior to McCafferty et al. (2005) should be considered a molecular component, is needed spot along the posterior margin of to determine if P. punctiventris as it the segment that usually bleeds into with some skepticism. The former synonymy with Iswaeon anoka (as currently is defined represents one the intersegmental membrane (Fig. variable species or a species complex 100e). Most P. gloveri are similarly Pseudocloeon) and the similarity between Plauditus punctiventris potentially including species known to patterned (McCafferty and Waltz 1998; date only as adults. McCafferty and Jacobus 2001) but have and I. anoka make it clear that all thinner claws, among other characters. records of P. punctiventris should be

Figure 109. Plauditus punctiventris, larva. Figure 110. Wisconsin records of Plauditus punctiventris.

Baetidae 93 Copyright © 2016 by the Board of Regents of the University of Wisconsin System doing business as the division of Cooperative Extension of the University of Wisconsin-Extension. All rights reserved. University of Wisconsin-Extension, Cooperative Extension, in cooperation with the U.S. Department of Agriculture and Wisconsin counties, publishes this infor- mation to further the purpose of the May 8 and June 30, 1914, Acts of Congress. An EEO/AA employer, the University of Wisconsin-Extension, Cooperative Extension provides equal opportunities in employment and programming, including Title IX and ADA requirements. If you have a disability and require this information in an alternative format, or if you would like to submit a copyright request, please contact Cooperative Extension Publishing at 432 N. Lake St., Rm. 227, Madison, WI 53706; [email protected]; or (608) 263-2770 (711 for Relay).

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Mayfly Larvae of Wisconsin (G4074) I-06-2016