CHECKLIST OF WISCONSIN DRAGONFLIES

In 1975, William Hilsenhoff summarized dragonfly species (Odonata: Anisoptera) known from Wisconsin. There were reports of 90 species at that time, but one was found to be reported in error leaving the state's fauna at 89. To date, an additional 23 species have been reliably reported from the state. This checklist provides a current summary of these 112 dragonfly species with an indication of population and legal status, breeding habitat, and estimates of range and flight period based on records maintained by the Natural Heritage Inventory Program (NHI) of the Wisconsin Department of Natural Resources. Five species reported from Wisconsin, but never substantiated as part of the state's fauna, are listed in addition. Many of these new state records added since 1975 have not been published and are included here with the permission of the discoverers.

SPECIES: English names are, with one exception, from a website titled "The Odonata of North America" http://www.ups.edu/biology/museum/NAdragons.html maintained by The Dragonfly Society of the Americas. Species are grouped phylogenetically by family. Species names in each family are arranged in alphabetical order.

STATUS: Population status is indicated with the Global and State species ranks as defined below. The Wisconsin DNR's Natural Heritage Inventory Program (NHI) utilizes this species population ranking system for all plant and animal species found in the state. Global ranks are maintained by "NatureServe," an organization stemming from The Nature Conservancy, which collects and develops authoritative information about the plants, animals, and ecological communities of the Western Hemisphere. State ranks are assigned by NHI. Note, these ranks reflect current knowledge of the population status of each species and are subject to change whenever new information is available. The current biological and legal status of dragonflies as well as other biota in Wisconsin are available on the Endangered Resources Program Webpage http://www.dnr.state.wi.us/org/land/er/.

Definition of Biological Ranks

Global Species Ranks:

• Gl = Critically imperiled globally because of extreme rarity (5 or fewer populations or very few remaining individuals) or because of some factor(s) making it especially vulnerable to extinction.
• G2 = Imperiled globally because of rarity (6 to 20 populations or few remaining individuals) or because of some factor(s) makes it very vulnerable to extinction throughout its range.
• G3 = Vulnerable to extinction throughout its range because it is rare (21 to 100 populations or individuals) and local throughout its range, or found locally (even abundantly at some of its locations) in a restricted range (e.g., a single state, a physiographic region), or because of other factors.
• G4 = Apparently globally secure, although it may be quite rare in parts of its range, especially at the periphery.
• G5 = Demonstrably secure globally, although it may be quite rare in parts of its range, especially at the periphery.

State Species Ranks:

• Sl = Critically imperiled in the state because of extreme rarity (5 or fewer populations or very few remaining individuals) or because of some factor(s) making it especially vulnerable to extirpation from the state.
• S2 = Imperiled in the state because of rarity (6 to 20 populations or few remaining individuals) or because of some factor(s) makes it very vulnerable to extirpation from the state.
• S3 = Rare or uncommon in the state (21 to 100 populations).
• S4 = Apparently secure in the state, with many populations.
• S5 = Demonstrably secure in the state and essentially uneradicable under present conditions.
• SA = Accidental in the state, including species recorded once or twice or only at very great intervals, hundreds or even thousands of miles outside of their usual ranges; a few of these species may even have bred on one or two occasions.
• SH = Of historical occurrence in the state, perhaps having not been verified in the past 20 years, and suspected to be still extant. A species would become SH without such a 20 year delay if the only known population in the state were destroyed, or if it bad been extensively and unsuccessfully looked for. Upon verification of an extant population, SH ranked species would typically receive a Sl rank.
• SR = Reported from the state, but without persuasive documentation which would provide a basis for either accepting or rejecting the report. Some of these are very old single records for which the NHI program hasn't yet received first hand information; others are old, obscure reports that are hard to dismiss because the habitat is now destroyed.
• SRF = Reported falsely (in error) from the state, but this error persists in the literature. The limits of uncertainty with regard to rank are indicated by a range (e.g., "G1G2" or "S2S3"), and species with a questionable taxonomic assignment are given a "Q" after the Global rank.

Definition of Legal Status Codes

U.S. Fish and Wildlife Service and WI DNR legal status is also given as a superscript after the species' name when appropriate as follows:

• 1 = WI Endangered or Threatened
• 2 = WI Special Concern (no protection)
• 3 = Federally Endangered or Threatened
• No number given means there is no legal status.

BREEDING HABITAT: Suitable aquatic habitat for the larvae is a primary factor determining odonate presence. Important habitat parameters include substrate, waterbody size, dissolved oxygen content, rate of flow, pH, structure of emergent and submergent vegetation, and water quality. The adjacent terrestrial land use and land cover can also be limiting. Many dragonflies, especially stream species, are apparently limited to waterbodies in largely forested watersheds.

RANGE: With a few exceptions, systematic surveys for Wisconsin dragonflies have not been conducted and as a result ranges given here are generalized to broad map units. Wisconsin range delineation's are made using a modified version of Leslie A. Ferge's floristic province divisions from his Checklist of Wisconsin Butterflies, with permission of the author. More detailed range delineations are given when known, based on knowledge of the distribution of suitable habitat or relatively complete surveys. See Figure 1. When records are restricted to a section of a region, its designation is modified to reflect this; e.g., southern section of the Western region = "W(s)." When records appear to be concentrated near a major river, that river's (abbreviated) name follows the region designation. Lower Wisconsin River = "LWR," Mississippi River = "Miss R," Saint Croix River = "St Cr R." Some species appear to have the Northern portion (or the entirety) of their range limited to the Door County peninsula; this is indicated by "N(Door)". Some species appear to have the Western portion of their range concentrated in the Baraboo Range; this is indicated by "W(Baraboo)." Some records in the Milwaukee area are entirely historical (occurring near the beginning of the 20th century); this group is indicated by "E h." The order of ranges listed reflects the representation of each range in the distribution of records, with the range with the most occurrences listed first, and so on. Map unit abbreviations are as follows:

Figure 1

N = Northern Highland
C = Central Sands
W = Western Upland (driftless area)
E = Eastern Ridges and Lowlands

NOTE: Some records appear to fall on the border between two regions; this is indicated by a slash between the designations. For instance, between the Central and Western regions = "C/W."

FLIGHT PERIOD: The range of dates given for adult presence begins with the earliest recorded larval emergence (often as evidenced by exuviae) and ends with the latest recorded capture or sighting of an adult. Most species require one to two weeks to become sexually mature after emergence and usually are not seen in their breeding habitat until then. In an attempt to summarize the available data, the authors have used the following convention when indicating the times of the earliest emergence and latest adult records:

• E (month) = from the 1st to the 10th day of that month
• M (month) = from the 11th to the 21st of that month
• L (month) = from the 22nd to the end of that month

Be advised that these flight periods are approximate; for instance, adults may still be flying in the middle of a month even though the latest recorded sighting occurred on the tenth day of that month.

The NHI is actively compiling records of dragonflies on the current Working List at http://dnr.wi.gov/org/land/er/working_list/taxalists/. Readers are encouraged to contribute species occurrence records to the senior author. We are especially interested in detailed information on species considered very rare, i.e. State rank of Sl, S2, and SH.

FAMILY: AESHNIDAE (DARNERS); GOMPHIDAE (CLUBTAILS); CORDULEGASTRIDAE (SPIKETAILS); MACROMIIDAE (CRUISERS); CORDULIIDAE (EMARALDS); LIBELLULIDAE (SKIMMERS); REPORTED FROM WISCONSIN, BUT NOT SUBSTATIATED

ACKNOWLEDGEMENTS: In addition to data provided by the authors, information was obtained from the following sources: "Aquatic Insects of Wisconsin" by William L. Hilsenhoff, 1981 (Publication of the Natural History Council, University of Wisconsin Madison, No. 2); "The Odonata of Canada and Alaska Volume II" by Edmund M. Walker, 1958, and "Volume III" by Edmund M. Walker and Philip Corbet, 1975 (University of Toronto Press); Dr. Kenneth Tennessen; Dr. Thomas Pleyte; The Milwaukee Public Museum; Susan Borkin; Dr. Everett D. Cashatt; Corbin Smith; Brendon Smith; Richard Lillie; David Heath; Glenn Miller, Robert DuBois, Karl Legler, Dave Westover, and the UW Stevens Point Biomonitoring database.