The Mecoptera of North America

Panorpa oconee from Gwinnett County, Georgia



            The Mecoptera (scorpion-flies, hanging-flies, winter scorpion-flies, and earwig-flies) of North America have some fascinating biogeographical patterns.  There are five families of Mecoptera present in North America: the Bittacidae (hanging-flies), Boreidae (snow scorpion-flies), Meropeidae (earwig-flies), Panorpidae (true scorpion-flies), and Panorpodidae.  Each of these families is a part of a broader north temperate or tropical fauna and each has had a long, independent evolutionary history, so that they can be discussed separately.  The geographical patterns indicate that the faunal in the western part of the region is quite different and probably separately derived from that of the eastern part of the region.  Byers (1969) has discussed the center of mecopteran diversity in the southern Appalachians, while Penny (2006) has pointed out the rich diversity of the California fauna.  Both areas were probably greatly influenced by the Pleistocene Ice Ages, refugia in these two areas, and subsequent shifts in distribution due to rising temperatures.


            The Bittacidae has been the most successful family in tropical regions, but has representatives that can also be found in cold temperate regions of the world.  In North America Bittacus strigosus can be found as far north as Winnipeg, Manitoba at almost 50° north latitude in a severe continental climate.  Unlike most other parts of the world, large numbers of adult bittacids can often be found by the thousands resting on the river bottom vegetation in mid-summer (Setty, 1940).  Adults are predatory, hanging from vegetation by their forewings and grabbing prey (small insects) with their raptorial hindtarsi.  Larvae live at the soil surface and have been raised on pieces of earthworm and crushed flies (Setty, ibid).

           The dominant genus in North America is Bittacus with seven species found in both the eastern and western Regions.  There are three additional, monotypic genera: Apterobittacus, Hylobittacus, and Orobittacus.  Apterobittacus is only found in coastal California; Hylobittacus is common in much of the forested parts of the eastern U.S.; and Orobittacus is only known from two localities along the American River in the lower reaches of the Serra Nevada of California.  Orobittacus has some morphological character states that indicate a very early separation from other bittacid genera.


Apterobittacus apterus  (McLachlan, 1871) U.S.A. (CA)

Bittacus chlorostigma  (McLachlan, 1881)   U.S.A. (CA, OR)

Bittacus occidentis  Walker, 1853  U.S.A. (AL, AR, AZ, DC, DE, IA, IL, IN, KS, KY, MD, MO, NC, NE, NY,


Bittacus pilicornis  Westwood, 1846  Canada, U.S.A. (AL, AR, DC, FL, GA, IA, IL, IN, KS, KY, LA, MA, MD,


Bittacus punctiger  Westwood, 1846  U.S.A. (AL, DC, FL, GA, IL, IN, MD, MS, NC, TN, TX, VA, WV) 

Bittacus stigmaterus  Say, 1823  U.S.A. (CT, DC, FL, GA, IA, IL, IN, KS, KY, LA, MD, MI, MO, MS, NC,


Bittacus strigosus  Hagen , 1861  U.S.A. (AL, AR, CT, DC, IA, IL, IN, KS, KY, MA, MD, MI, MN, MO, MT,

NC, ND, NE, NH, NJ, NY, OH, OK, PA, SC, TN, VA, VT, WV, WY), Canada (MB, PQ)

Bittacus texanus  Banks, 1908  U.S.A. (KS, NM, TX) 

Hylobittacus apicalis  (Hagen, 1861)  U.S.A. (AL, AR, GA, IL, IN, KY, MI, MO, NC, NY, OH, OK, PA, TN,


Orobittacus obscurus  Villegas & Byers, 1981  U.S.A. (CA)


            The family Boreidae, or winter scorpion-flies, is a group of small, dark mecopterans that emerge as adults during the coldest time of year in some of the coldest parts of the Northern Hemisphere.  There are three genera in the family, two of them endemic to western North America.  Larvae are grub-like and both larvae and adults feed on mosses (Boreus and Hesperoboreus) and liverworts (Caurinus).  Adults have highly reduced wings, and avoid being killed by the winter cold by having a large amount of colloidal material in their blood; becoming inactive as temperatures fall; feeding on mosses on dark rocks that adsorb heat; and climbing under snow to be better insulated.  In the most southern part of their distribution, larval boreids are known to create cells in the soil during dry summers and await the early winter rains for further development to adults (Cooper, 1974).  The monotypic genus Caurinus of the Pacific Coast area of the U.S. is even more reduced than other boreids and has been placed in its own subfamily.


Boreus bomari  Byers & Shaw, 2000  (WY)            

Boreus borealis  Banks, 1923  (AK) 

Boreus brumalis  Fitch, 1847  (DC, IL, MA, MI, MN, NY, OH, TN, VA, WS; Canada: PQ)

Boreus californicus  Packard , 1870 (AZ, CA, ID, MT, NV, OR, WA, WY; Canada: AB, BC)

= Boreus unicolor Hine, 1901

= Boreus isolatus  Carpenter, 1935

= Boreus californicus fuscus  Carpenter, 1935

Boreus coloradensis  Byers , 1955  (CO, MT, UT, WY)

Boreus elegans  Carpenter, 1935  (WA; Canada: BC)

Boreus insulanus  Blades, 2002  (Canada: BC)

Boreus intermedius  Lloyd, 1934  (AK)

Boreus nivoriundus  Fitch, 1847  (MA, ME, NH, NY, OH, TN, VT)

Boreus nix  Carpenter, 1935  (AK, MT; Canada: BC)

= Boreus gracilis  Carpenter, 1935  

Boreus pilosus  Carpenter, 1935  (MT; Canada: AB, BC)

Boreus reductus  Carpenter, 1933  (ID, MT, NV, WA; Canada: BC)


Caurinus dectes  Russel l , 1979  (OR)


Hesperoboreus brevicaudus  (Byers, 1961)  (OR, WA)

Hesperoboreus notoperates  (Cooper, 1972)  (CA)



            The family Meropeidae is found only in Western Australia and eastern North America.  This strikingly disjunct distribution was theorized by Byers (1973) to have come about through a Gondwanian distribution with connections in South America.  In this paper Byers speculates as to whether an undiscovered species of Meropeidae may exist in southern South America.  In this same paper Byers has described the unusual anomaly in collections of the North American species.  For approximately 150 years after its original description, Merope tuber was only collected east of the Appalachian Mountains.  Then, during the past 60 years most of the collections have been made in the Midwest and the southern Appalachians (Dunford et al., 2007).

            Despite the extensive distribution of Merope tuber, the immature stages have never been described.  According to Byers (1973), “Its immature forms are still unknown, and the discovery of them is certainly the most exciting thing left to be done in the study of North American Mecoptera”.

            Meropeidae adults have a distinctive, reticulate venation and males have long, tubular claspers unlike any other group of mecopterans.  Most studies of phylogeny place this group at the base of the order, and in some cases, at the base of the holometabolous insects.


Merope tuber  Newman, 1838  (AR, DC, FL, GA, IA, IL, IN, KS, KY, MD, ME, MI, MN, MO, NC. NJ, NY, OK,

PA, VA, WS, WV; Canada: ON)


                The family Panorpidae is, by far, the most speciose group of mecopterans in North America.  At this time only a single genus is recognized, Panorpa, forming part of a discontinuous distribution that stretches across the Northern Hemisphere from Siberia and Japan across Asia and Europe to eastern North America.  The break in this range comes in western North America, which has no Panorpidae, except for a couple of reports of Panorpa from the high mountains of Utah.  The radiation of species is especially great in the coastal region of the southeastern United States and the southern Appalachian Mountains (Byers, 1969).

                The genus Panorpa is the largest genus of Mecoptera with more than 200 described species (see Mecoptera World Catalog associated with these web pages), with 56 of them found in North America.  Panorpa is one of four genera in Panorpidae, the other three genera are known only from southern Asia.  In North America, Panorpa has traditionally been divided into several distinctive species groups, but these groups may actually be more deeply rooted in the evolution of the family than some currently recognized genera.  Several authors have pointed out the paraphyletic composition of Panorpa (Willmann, 1989; Misof et al., 2000; Whiting, 2002; Cai, et al, 2008; Ma et al., 2009; Xie and Hua, 2010) based both of morphological characters and molecular data.  A cladistic study of the family is badly needed.



                Perhaps the most difficult problem in North American Mecoptera systematics is where to draw the line between distinct species and variable populations, including regional differences.  As more collections are made in intermediate areas, distinctions between species have become more subtle and nuanced.  Possibly molecular studies can help better define the species limits and variability.


Panorpa debilis, caudal view of male genitalia.  Abbreviations:  AH = aedeagal hamulus; BL = basal lobe of dististyle; BS = basistyle; DS = dististyle; HV = hypovalve; VP = ventral parameres.  The right hypovalve has been removed for clarity.

Panorpa acuminata  Byers, 1993   U.S.A. (GA)

Panorpa acuta  Carpenter, 1931   U.S.A. (CT, GA, KY, MA, MI, NH, NJ, NY, NC, PA, SC, TN, VA, WV)

Panorpa americana  Swederus, 1787   U.S.A. (AL, DE, FL, GA, LA, MS, NJ, NC, SC, VA)

= Panorpa fasciata  Fabricius, 1793

Panorpa anomala  Carpenter , 1931  U.S.A. (AR, IA, IL, IN, KS, LA, MI, MO, MS, WS)

= Panorpa proximata  Carpenter, 1931

Panorpa appalachia  Byers, 2002  (NC)

Panorpa banksi  Hine, 1901  U.S.A. (GA, IA, IL, IN, KY, MA, ME, MI, MS, NC, NY, SC)

=  Panorpa affinis  Banks, 1895  (preoccupied)

=  Panorpa chelata  Carpenter, 1931

Panorpa banksiana  Penny & Byers, 1979  U.S.A. (NC, NJ)

= Panorpa interrupta  Banks, 1918  (preoccupied)

Panorpa bichai  Byers , 1993  U.S.A. (IN, TN)

Panorpa bifida  Carpenter , 1935  U.S.A. (OH, PA, TN, VA, WV)

Panorpa braueri  Carpenter , 1931  U.S.A. (AR, MO)

Panorpa capillata  Byers, 1996  U.S.A. (AL, AR, KY, MS, TN)

Panorpa carolinensis  Banks, 1905  U.S.A. (NC, TN) 

Panorpa choctaw  Byers , 1993  U.S.A. (AL, AR, GA, KY, MO, MS, OK, TN)

Panorpa claripennis  Hine, 1901  U.S.A. (CT, FL, MA, MI, NH, NY, OH, VT, WS, WV), Canada (PQ)

Panorpa confinis  Byers, 1993  U.S.A. (AL, MS) 

Panorpa consuetudinis  Snodgrass, 1927  U.S.A. (AL, CT, DC, DE, IN, MD, MS, NC, NJ, NY, OH, PA, SC,


= Panorpa elaborata  Carpenter, 1931

Panorpa debilis  Westwood , 1846  U.S.A. (DC, IL, IN, MI, NC, NH, NJ, NY, OH, PA, TN, VA, WS, WV),

Canada (ON, PQ)

= Panorpa canadensis  Banks, 1895

Panorpa dissimilis  Carpenter, 1931  U.S.A. (NJ, NY, VA)

Panorpa dubitans  Carpenter, 1931  U.S.A. (IL, IN, WS)

Panorpa ensigera  Bicha, 1983  U.S.A. (NC, SC)

Panorpa ferruginea  Byers, 1993  U.S.A. (AL, GA, MS)

Panorpa flexa  Carpenter , 1935  U.S.A. (GA, NC, SC, TN)

Panorpa floridana  Byers, 1993  U.S.A. (FL)

Panorpa galerita  Byers, 1962  U.S.A. (NH, NJ, NY, OH, PA, WS), Canada (PQ)

Panorpa gracilis  Carpenter, 1931  U.S.A. (NC, VA)

Panorpa helena  Byers, 1962  U.S.A. (AR, CT, GA, IA, IL, IN, KS, KY, MA, MD, ME, MI, MN, MO, NC, NJ,

NY, OH, PA, SC, TN, UT, VA, WS, WV), Canada (MB)

Panorpa hispida  Byers, 1993  U.S.A. (GA, SC)

Panorpa insolens  Carpenter, 1935  U.S.A. (KY, OH)

Panorpa isolata  Carpenter, 1931  U.S.A. (AL, DC, GA, KY, MS, NC, PA, SC, TN)

= Panorpa decorata  Carpenter, 1931

Panorpa latipennis  Hine, 1901  U.S.A. (CT, MA, MI, NC, NJ, NY, OH, TN, VA, VT, WS)

= Panorpa longipennis  Banks, 1911

Panorpa longicornis  Carpenter , 1931  U.S.A. (KY, NC, TN, VA)

Panorpa lugubris  Swederus , 1787  U.S.A. (AL, FL, GA, LA, MS, NC, SC, VA)

= Panorpa scorpio  Fabricius, 1793

Panorpa maculosa  Hagen, 1861  U.S.A. (CT, GA, MA, MI, NC, NJ, NY, OH, PA, SC,TN, UT, VA) 

Panorpa mirabilis  Carpenter, 1931  U.S.A. (MI, NJ, NY, PA)

Panorpa nebulosa  Westwood, 1846  U.S.A. (CT, GA, IL, KY, MA, ME, MI, MO, NC, NH, NJ, NY, OH,

PA, SC, TN, VA, VT, WS), Canada (ON, PQ) 

Panorpa neglecta  Carpenter , 1931  U.S.A. (AL, GA, KY, TN)

=  Panorpa hungerfordi  Byers, 1973  U.S.A. (IN, KY, MI, OH, WS)

Panorpa nuptialis  Gerstaecker , 1863  U.S.A. (AL, AR, KS, LA, MS, MO, OK, TX), Mexico

Panorpa oconee  Byers, 1993  U.S.A. (GA) 

Panorpa pachymera  Byers, 1993  U.S.A. (GA, SC)

Panorpa palustris  Byers, 1958  U.S.A. (NC, VA)

Panorpa planicola  Byers, 1993  U.S.A. (SC)

Panorpa robusta  Carpenter , 1931  U.S.A. (GA, SC)

Panorpa rufa  Gray, 1832  U.S.A. (AL, FL, GA, MS, NC, SC) 

Panorpa rufescens  Rambur , 1842  U.S.A. (CT, DC, MA, MD, MI, NH, NJ, NY, PA, RI)

=  Panorpa confusa  Westwood, 1846

Panorpa rupeculana  Byers, 1993  U.S.A. (AR, LA, MS) 

Panorpa scopulifera  Byers, 1993  U.S.A. (GA, SC)

Panorpa setifera  Webb, 1974  U.S.A. (WS)

Panorpa sigmoides  Carpenter, 1931  U.S.A. (IA, IL, IN, MN, OH, WS)

Panorpa speciosa  Carpenter , 1931  U.S.A. (IA, IL, IN, KY, MN, MO, WS)

Panorpa subfurcata  Westwood, 1842  U.S.A. (MA, ME, MI, MN, NJ, NY, PA, VA, WS, WV), Canada (NS,


=  Panorpa signifier  Banks, 1900

=  Panorpa modesta  Carpenter, 1931

=  Panorpa subulifera  Byers , 1962  U.S.A. (VA)

Panorpa submaculosa  Carpenter, 1931  U.S.A. (GA, IN, KY, MD, MI, NY, OH, PA, SC, TN, UT, WS)

=  Panorpa utahensis  Gurney, 1937

Panorpa venosa  Westwood, 1846  U.S.A. (GA) 

Panorpa vernalis  Byers, 1973  U.S.A. (AR, LA, MS) 

Panorpa virginica  Banks, 1906  U.S.A. (CT, GA, NC, NJ, SC, TN, VA)


                The family Panorpodidae is one of the smaller families of Mecoptera with only 13 species in two genera, Brachypanorpa and Panorpodes.  Panorpodids are only found in the cool, temperate parts of the Northern Hemisphere and today their distribution is quite disjunct.  Brachypanorpa is found in the Appalachian Mountains of eastern North America, and cooler, northern parts of western North America with a gap of about 1700 miles separating the two distributions.  Panorpodes is found in Japan, Korea, northern China, and California.  However, fossil Panorpodes are also known from Oligocene Baltic amber of Europe (Carpenter, 1954).  Pollmann et al. (2008) did a molecular phylogeny of this family and they found that the most basal species was Panorpodes colei from California.  Proceeding up the evolutionary ladder were species of Panorpodes from eastern Asia, Brachypanorpa from eastern North America, and finally Brachypanorpa from western North America.  If the assumption is made that evolving and migrating populations left relict populations in their place of origin, then we can surmise that Panorpodidae originated in western North America and then migrated westward across the Bering Straits to Asia, Europe, eastern North America, and finally returned to western North America over evolutionary time in the form of western Brachypanorpa species.  Panorpodids look much like true scorpion-flies (Panorpa) in size and shape, but can be separated by the shorter rostrum and tarsal claws without teeth.  Females of Brachypanora also have very short wings and are functionally flightless.  Adults of Panorpodes colei have a longer rostrum than Brachypanorpa, wings are paler and more transparent, and females are fully winged and strong fliers.


Brachypanorpa carolinensis  (Banks, 1905)  (NC)

Brachypanorpa jeffersoni  Byers , 1976  (NC, TN, VA)

Brachypanorpa montana  Carpenter, 1931  (OR)

Brachypanorpa oregonensis  (McLachlan, 1881)  (CA, ID, OR, UT)

Brachypanorpa sacajawea  Byers, 1990  (ID, MT)


Panorpodes colei  Byers, 2004  (CA)


Acknowledgments:  Donald W. Webb is to be thanked for much of the pioneering work done on the Mecoptera fauna of the upper Midwest.  We have enjoyed many days discussing the Illinois fauna and its broader implications.  George W. Byers has been a very good and patient mentor over the years.  In many ways he has created the classification that we use today, and created the detailed illustrations that we use to identify the fauna.  Wes Bicha has contributed many of the rare species that are illustrated in these web pages through his extensive field collecting, and has always proven eager to participate and  help.  This project could not have been accomplished without his help. These three individuals: Don Webb, George Byers, and Wes Bicha have developed an enthusiastic camaraderie for what had previously been an obscure, little-studied group of insects.  Oliver S. Flint, Jr. has shown his interest in the Mecoptera through fascinating stories of collecting unusual species and tracking down historical points about distributions.  Rachel Diaz-Bastin took the Syncroscopy Auto-Montage© images.  Amanda Kershaw put together the web pages. Finally, my wife, Ana Penny, has helped collect, photograph, and prepare many of the specimens used. 



Byers, G.W. 1969. Ecological and geographical relationship of Southern Appalachian Mecoptera (Insecta), pp.265-276, in Holt, P.C., ed., The Distributional History of the Biota of the Southern Appalachians Part 1:Invertebrates. 295 pp.


Cai, Li-Jun, Peng-Ying Huang, and Bao-zhen Hua.  2008.  Sinopanorpa, a new genus of Panorpidae (Mecoptera) from the Oriental China with descriptions of two new species.  Zootaxa  1941:43-54.


Carpenter, F.M. 1954. The Baltic Amber Mecoptera. Psyche. 61:31-40.


Cooper, K.W. 1974. Sexual Biology, Chromosomes, Development, Life Histories and Parasites of Boreus, especially of B. notoperates. A Southern California Boreus. II. (Mecoptera: Boreidae). Psyche, 81:84-120.


Dunford, JC, PW Kovarik, LA Somma, D Serrano. 2007. First state records for Merope tuber (Mecoptera: Meropidae) in Florida and their biogeographical implications. Florida Entomologist. 90:581-584.


Ma, N., Cai, L.J. & Hua, B.Z.  2009.  Comparative morphology of the eggs in some Panorpidae (Mecoptera) and their systematic implication. Systematics and Biodiversity, 7, 403–417.


Misof, B., D. Erpenbeck, and K.P. Sauer.  2000.  Mitochondrial Gene Fragments Suggest Paraphyly of the Genus Panorpa (Mecoptera: Panorpidae).  Mol. Phyl. Evolution 17:76-84.


Penny, N.D.  2006.  A Review of our knowledge of California Mecoptera.  Proceedings of the California Academy of Sciences  Ser. 4, 57(9):365-372, 4 figs., 3 maps.


Setty,  L.R. 1940. Biology and morphology of some North American Bittacidae (Order Mecoptera). American Midland Naturalist, 23:257-353.


Whiting,  M.F.  2002.  Mecoptera is paraphyletic: multiple genes and phylogeny of Mecoptera and Siphonaptera. Zoologica Scripta, 31, 93–104.


Willmann, R. 1989. Evolution und Phylogenetisches System der Mecoptera (Insecta: Holometabola). [In German with English summary]. Abhandlungen Senckenbergischen Naturforschenden Gesellschaft, No. 544:1-153.


Xie, S. & Hua, B.Z.  2010.  Sperm ultrastructure in two species of Panorpa and one Bittacus (Mecoptera). Micron, 41, 622–632.


A Bibliography of Mecoptera


A World Catalog of Mecoptera

The Mecoptera of Taiwan

The Mecoptera of North America


The Mecoptera of Chile


The Mecoptera of Mexico (in progress)


The Mecoptera of Gaoligongshan, Yunnan, China (in progress)


  • Norm Penny
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