Animal Diversity Web

Ge­o­graphic Range

Ophio­gom­phus howei, com­monly known as the pygmy snake­tail drag­on­fly, is a na­tive species to North Amer­ica. Pygmy snake­tail drag­on­flies are found on the east­ern half of North Amer­ica in two dis­tinct lo­ca­tions; one pop­u­la­tion which fol­lows along the Ap­palachian re­gion ex­tend­ing from Ten­nessee to New Brunswick, On­tario, and the west­ern pop­u­la­tions in Michi­gan, Min­nesota, and Wis­con­sin. The pygmy snake­tail drag­on­fly can be found in ten known U.S. states: Ken­tucky, Maine, Mass­a­chu­setts, Michi­gan, Min­nesota, New York, North Car­olina, Penn­syl­va­nia, Ten­nessee, and Wis­con­sin. Ophio­gom­phus howei can be found in the Cana­dian ter­ri­to­ries of On­tario and Que­bec in var­i­ous lo­ca­tions. Much of north­west­ern On­tario and the west­ern United States are with­out suit­able habi­tat due to the lim­i­ta­tions as­so­ci­ated with this species which in­cludes large, clear, fast-mov­ing rivers with fine gravel sub­strate. (Ab­bott and Don­nelly, 2013; Brunelle, 2008; Hamill, 2013)

• Biogeographic Regions
• nearctic
  • native

Habi­tat

Lar­vae of the pygmy snake­tail drag­on­fly are found in large rivers with clear, fast-flow­ing, and un­pol­luted run­ning wa­ters and sub­strates of fine sand or pea sized gravel. The medium to large sized rivers range from 10 me­ters to 200 me­ters wide with fine sub­strate stream beds. Lar­vae do not occur in areas below dams, since the species is un­able to breed at such deep depths. They are typ­i­cally found at depths of 1 to 4 m.

The ma­jor­ity of adult life for Ophio­gom­phus howei species is spent hid­den in forests along large rivers, which makes this species par­tic­u­larly dif­fi­cult to study. The for­est sur­round­ing the river is needed, par­tic­u­larly for fe­males, to pro­vide habi­tat for for­ag­ing and mat­ing. The spe­cific type of for­est re­quired has not been de­scribed in pub­li­ca­tions, but is most likely a mix­ture of de­cid­u­ous and conif­er­ous for­est. (Ab­bott and Don­nelly, 2013; Brunelle, 2008; Hamill, 2013)

• Habitat Regions
• temperate
• terrestrial
• freshwater

• Terrestrial Biomes
• forest

• Aquatic Biomes
• lakes and ponds
• rivers and streams

• Other Habitat Features
• riparian

• Range depth

  1 to 4 m

  3.28 to 13.12 ft

Phys­i­cal De­scrip­tion

Sim­i­lar to other drag­on­fly species, lar­vae of pygmy snake­tail drag­on­fly are flat, brown, and have di­ver­gent wing cases. Lar­vae can eas­ily be iden­ti­fied from other mem­bers of the genus Ophio­gom­phus by their small size (19 to 22 mm in length), by their lack of dor­sal ab­dom­i­nal spines, and ab­sence of lat­eral hooks on the ab­dom­i­nal seg­ment 7. The ab­dom­i­nal re­gion also shows long cerci, which are a pair of upper ap­pendages at the tip of seg­ment 10 at the end of the ab­domen.

The ma­ture nymph of Ophio­gom­phus howei is green­ish brown in color with a body cov­ered with coarse gran­ules to help it blend into the river bot­tom. Ear­lier in­stars have more of a yel­low­ish-brown body. The body length is on av­er­age 20.5 mm, ab­dom­i­nal width 5.6 mm, and head width 4.7 mm.

The adults of Ophio­gom­phus howei are the small­est (31 to 37 mm long) mem­bers of the Ophio­gom­phus genus as the com­mon name of "pygmy snake­tail drag­on­fly" im­plies, and is one of the smaller drag­on­flies in North Amer­ica with a hind-wing length of 19 to 21 mm and ab­domen length of 22 to 24 mm. The adults have dis­tinc­tive mark­ings and col­oration show­ing a bright green tho­rax, vivid yel­low mark­ings on the dor­sal ab­domen, and each wing is marked basally with a large, trans­par­ent yel­low-or­ange patch. In the ten­eral stage, the tho­racic mark­ings are yel­low for up to seven days.

Com­pared to other drag­on­flies of this genus the pygmy snake­tail drag­on­fly has a greater flared ab­domen. The fe­male re­sem­bles the male ex­cept for its thicker ab­domen, re­duced flare, lack of sec­ondary gen­i­talia, pres­ence of an ovipos­i­tor, and dif­fer­ent num­ber and shape of the ab­dom­i­nal ap­pendages. The inner or basal por­tions of the hind-wings are yel­low (basal half of the hind-wings in males, basal two-thirds of the hind-wings in fe­males). The ab­domen is de­scribed as hav­ing a "club­tail" since it is slightly widened at the end.

The ab­domen is black in color with small, yel­low spots on top that are tri­an­gu­lar in shape and of var­i­ous sizes. All ab­dom­i­nal seg­ments have a yel­low, tri­an­gu­lar spot on top ex­cept for the last seg­ment at the pos­te­rior end of the ab­domen (seg­ment 10). The eyes of this drag­on­fly are sim­i­lar to other drag­on­fly species, col­ored green and do not meet at the top of the head. Fe­males can be dis­tin­guished from males be­cause they have a short, sharp horn on each side of the rear of the head. (Brunelle, 2008; Hamill, 2013; Kennedy and White III, 1979; Lee, 2009; "Ophio­gom­phus howei - Brom­ley, 1924", 2013; Ten­nessen, 1993)

• Other Physical Features
• ectothermic
• heterothermic
• bilateral symmetry

• Sexual Dimorphism
• sexes colored or patterned differently
• sexes shaped differently

• Range length

  31 to 37 mm

  1.22 to 1.46 in

• Range wingspan

  19 to 21 mm

  0.75 to 0.83 in

De­vel­op­ment

Ophio­gom­phus howei ex­hibits hemimetabolous meta­mor­pho­sis, mean­ing a grad­ual de­vel­op­ment with three dis­tinct stages that some­what re­sem­ble one an­other and lacks a pupal stage. Stages for the life cycle in­cludes an aquatic egg, aquatic larva, and a ter­res­trial/aer­ial adult. As with most drag­on­flies, the pygmy snake­tail spends most of its life as an aquatic larva. After the eggs hatch, the lar­vae bur­row into gravel or sand sub­strates where they grow and de­velop. As the lar­vae grow, they shed or molt their skin nu­mer­ous times. Most drag­on­fly species trans­form into adults in one to three years. A few stud­ies have in­di­cated the pygmy snake­tail drag­on­fly may have a two-year life cycle.

At the end of their lar­val de­vel­op­ment, the lar­vae climb out of the water and at­tach them­selves to veg­e­ta­tion, rocks, tree roots, woody de­bris, bare ground, or other struc­tures or sur­faces lo­cated along the stream banks or float­ing in the water as they trans­form into the adult stage. The lar­vae un­dergo a final molt and emerge as winged adults. Newly emerged adults, or ten­er­als, typ­i­cally re­main perched for one or two hours to dry their wings be­fore they can fly. Adult drag­on­flies be­come sex­u­ally ma­ture within a week or up to a month after emer­gence. (Bradeen and Boland, 2004; Lee, 2009; "The Uni­ver­sity of Ari­zona Cen­ter for In­sect Sci­ence Ed­u­ca­tion Out­reach", 1997)

• Development - Life Cycle
• metamorphosis

Re­pro­duc­tion

Adult pygmy snake­tail drag­on­flies be­come sex­u­ally ma­ture usu­ally within a week or up to a month after emer­gence. Males will ini­ti­ate mat­ing by grasp­ing fe­males with their legs and ter­mi­nal ap­pendages, then the con­nected pairs fly in tan­dem to nearby veg­e­ta­tion or tree canopies to mate. Breed­ing oc­curs sea­son­ally usu­ally dur­ing spring or early sum­mer. Most likely pygmy snake­tail drag­on­flies are polyg­y­nan­drous, with both males and fe­males hav­ing mul­ti­ple mates. (Lee, 2009; "Ophio­gom­phus howei - Brom­ley, 1924", 2013)

• Mating System
• polygynandrous (promiscuous)

After mat­ing, fe­males lay their eggs in rif­fles or rapids in streams and rivers by dip­ping their ab­domen in the mov­ing water. The eggs are car­ried by the water and are de­posited in spaces in the rock, gravel, and/or sand sub­strate of the stream or river. Adult pygmy snake­tail drag­on­flies are ob­served oc­ca­sion­ally at breed­ing sites, but gen­er­ally are not seen as fre­quently or in large num­bers after the adult emer­gence pe­riod com­pared to other drag­on­fly species. This issue leads to a lack of cur­rent in­for­ma­tion on the num­ber of off­spring pro­duced per breed­ing sea­son and other re­pro­duc­tive in­for­ma­tion. Stud­ies like the one by Gibbs et. al. (2004) in­di­cates that the pygmy snake­tail drag­on­fly likely re­quires two or more years to com­plete a gen­er­a­tion. It also likely has over­lap­ping gen­er­a­tions and pro­duces more than one brood or gen­er­a­tion per year. (Bradeen and Boland, 2004; Lee, 2009)

• Key Reproductive Features
• iteroparous
• seasonal breeding
• gonochoric/gonochoristic/dioecious (sexes separate)
• sexual
• fertilization
  • internal
• oviparous

• Breeding interval

  Ophiogompus howei mates multiple times during its breeding season.

• Breeding season

  Breeding takes place in the spring or early summer.

• Average time to independence

  0 minutes

• Range age at sexual or reproductive maturity (female)

  1 to 3 weeks

• Range age at sexual or reproductive maturity (male)

  1 to 3 weeks

Fe­male pygmy snake­tail drag­on­flies lay their eggs in suit­able aquatic habi­tats for the lar­vae to sur­vive in upon hatch­ing. They also pro­vide pro­vi­sion­ing in the eggs. After lay­ing her eggs, the fe­male drag­on­fly then leaves the area and the eggs are car­ried away by the water. Males are only used in fer­til­iza­tion and have no role in parental in­vest­ment. (Lee, 2009; "Ophio­gom­phus howei - Brom­ley, 1924", 2013)

• Parental Investment
• pre-hatching/birth
  • provisioning
    • female

Lifes­pan/Longevity

As with most drag­on­flies, the Ophio­gom­phus howei spends most of its life as an aquatic larva. The over­all lifes­pan for O. howei is de­pen­dent on lar­val and nymph stages which is highly vari­able due to vul­ner­a­bil­ity to birds, frogs, lizards, fish, and other large drag­on­flies, weather, and pol­lu­tion. The time re­quired for pygmy snake­tail lar­vae to de­velop into adults is cur­rently not known. Most drag­on­fly species trans­form into adults in one to three years. In gen­eral, adult drag­on­flies typ­i­cally live for ap­prox­i­mately one month, and up to nine months to a year in a few species. (Lee, 2009)

• Average lifespan
  Status: wild

  2 years

Be­hav­ior

Adult drag­on­flies need sunny warm weather to fly, with a tem­per­a­ture over 65°C ideal. Dur­ing in­clement weather such as cold and rainy days, O. howei tends to hide or lay in veg­e­ta­tion. Adult male drag­on­flies often es­tab­lish ter­ri­to­ries along the edges of ponds or streams and only de­fend the ter­ri­tory against other males of their species. The lar­val and nymph stages of Ophio­gom­phus howei are mainly soli­tary within a river or stream, but they may travel within the river or stream over the span of the species life. (Ham­mond, 2014)

• Key Behaviors
• arboreal
• flies
• natatorial
• diurnal
• motile
• solitary
• territorial

Home Range

Since the pygmy snake­tail drag­on­fly spends most of its ex­pected life within a river, the home range of typ­i­cal species could ex­tend from about 1300 km or (ap­prox 800 miles) over the span of a river. Most of the adult life of the drag­on­fly is spent in close veg­e­ta­tion or trees about (7 to 10 me­ters) off the ground di­rectly next to the river, and may mi­grate along the length of the river or stream. (Kennedy and White III, 1979; Ten­nessen, 1993)

Com­mu­ni­ca­tion and Per­cep­tion

Adult pygmy snake­tail drag­on­flies are sim­i­lar to other drag­on­fly species who com­mu­ni­cate vi­su­ally. Mat­ing pairs prob­a­bly com­mu­ni­cate by touch, shown when an adult male grasps fe­males with their legs and ter­mi­nal ap­pendages and its pos­si­ble that chem­i­cal com­mu­ni­ca­tion may play a role in re­pro­duc­tion as well. Adult males also fight aer­ial duels for ter­ri­to­ries, dis­play­ing their size and speed to each other in order to com­mu­ni­cate and ward off other drag­on­fly species. (Ham­mond, 2014; Har­ris, et al., 2011; Lee, 2009)

• Communication Channels
• visual
• tactile
• chemical

• Perception Channels
• visual
• ultraviolet
• tactile

Food Habits

Both adult and lar­val pygmy snake­tail drag­on­flies are known as in­tensely fe­ro­cious car­ni­vores and preda­tors of most in­sect species. Pygmy snake­tails have great speed in both the air and water, which al­lows them to sneak and cap­ture prey. Lar­vae have been re­ported to feed on water mites, mayfly nymphs, and chi­rono­mids or midges as they hide be­hind rocks, gravel, sticks, and other de­bris from which they at­tack un­sus­pect­ingly. Adult drag­on­flies typ­i­cally for­age for fly­ing in­sects, such as but­ter­flies, moths, dam­selflies, mos­qui­toes, and flies, in sunny areas in­clud­ing open grassy fields, for­est open­ings, and over streams and rivers. (Kennedy and White III, 1979; Lee, 2009)

• Primary Diet
• carnivore
  • insectivore

• Animal Foods
• insects
• terrestrial non-insect arthropods
• aquatic or marine worms

Pre­da­tion

Preda­tors of adult drag­on­flies in­clude birds, frogs, lizards, fish, and other large drag­on­flies. When the drag­on­fly has use of its wings, it is quick and agile in flight, and hides in veg­e­ta­tion when it is too cold to fly. The O. howei species has adapted bright mark­ings and a "club­tail" which most likely serves to warn off preda­tors. Adult pygmy snake­tail drag­on­flies also have high mor­tal­ity rates due to human dis­tur­bance or en­vi­ron­men­tal fac­tors such as wind/rain after the ini­tial hatch­ing time when the wings of the drag­on­fly are wet for one or two hours. The col­oration of lar­vae likely serves as cam­ou­flage in its aquatic habi­tat. (Ham­mond, 2014; Lee, 2009)

• Anti-predator Adaptations
• cryptic

• Known Predators

  • fish
  • birds, Aves
  • frogs, Anura
  • lizards, Squamata
  • aquatic insects, Insecta
  • dragonflies, Odonata

Ecosys­tem Roles

Pygmy snake­tail drag­on­flies are an im­por­tant species in their habi­tats. The preda­tors of pygmy snake­tail drag­on­flies such as birds, frogs, lizards, fish, and other large drag­on­flies all con­sume this species and pygmy snake­tails con­sume water mites, mayfly nymphs, chi­rono­mids or midges, but­ter­flies, moths, dam­selflies, mos­qui­toes, and flies. With­out the pygmy snake­tail many species within the food web would be af­fected. An­other im­por­tant role Ophio­gom­phus howei pro­vides is soil aer­a­tion. The lar­vae hide in be­tween rocks and gravel and tends to move small gran­u­lar sized sand grains at the bot­tom of streams and rivers, which serves to break up soil and al­lows water and air to enter the open cav­ity. (Lee, 2009)

• Ecosystem Impact
• soil aeration

Eco­nomic Im­por­tance for Hu­mans: Pos­i­tive

Pygmy snake­tail drag­on­flies are eco­nom­i­cally im­por­tant for hu­mans as they help to con­trol pop­u­la­tions of mos­qui­toes. Ophio­gom­phus howei has also pro­vided ample op­por­tu­ni­ties for re­search, in­clud­ing such top­ics as re­pro­duc­tive ac­tiv­i­ties and tim­ing, ef­fects of in­va­sive species, food pref­er­ences and for­est habi­tat needs of adults, re­col­o­niza­tion abil­i­ties of the species after ex­tir­pa­tion, po­ten­tial for and fea­si­bil­ity of rein­tro­duc­tion after ex­tir­pa­tion. (Hamill, 2013)

• Positive Impacts
• research and education
• controls pest population

Eco­nomic Im­por­tance for Hu­mans: Neg­a­tive

There are no known ad­verse ef­fects of Ophio­gom­phus howei on hu­mans.

Con­ser­va­tion Sta­tus

Threats to the ma­jor­ity of the pygmy snake­tail drag­on­fly in the north­ern range are mod­er­ate, but habi­tat threats to pop­u­la­tions in the south ap­pear to be more sig­nif­i­cant. These po­ten­tial threats to habi­tat degra­da­tion can ac­count from human ac­tiv­i­ties that ruin run­ning wa­ters through poorly drained roads, damming, and also nat­ural ac­tiv­i­ties such as beaver damming, chan­nel­iza­tion lead­ing to scour of mi­cro­hab­i­tats, toxic or or­ganic pol­lu­tion, and in­tro­duc­tions of ex­otic species. The ma­jor­ity of re­pro­duc­tion which in­cludes mi­gra­tion is ef­fected by cli­mate and weather and will be po­ten­tially im­pacted with rapid cli­mate changes. (Ab­bott and Don­nelly, 2013)

• IUCN Red List

  Least Concern

• US Federal List

  No special status

• CITES

  No special status

• State of Michigan List

  Threatened

Con­trib­u­tors

Brock Bermel (au­thor), Min­nesota State Uni­ver­sity, Mankato, Robert Sorensen (ed­i­tor), Min­nesota State Uni­ver­sity, Mankato, An­gela Miner (ed­i­tor), An­i­mal Di­ver­sity Web Staff.

Ref­er­ences

Na­ture­Serve. 2013. "Ophio­gom­phus howei - Brom­ley, 1924" (On-line). Na­ture­Serve. Ac­cessed March 26, 2014 at http://​explorer.​natureserve.​org/​servlet/​NatureServe?​searchName=Ophiogomphus+howei+.

The Uni­ver­sity of Ari­zona. 1997. "The Uni­ver­sity of Ari­zona Cen­ter for In­sect Sci­ence Ed­u­ca­tion Out­reach" (On-line). In­sect In­for­ma­tion: Life Cy­cles. Ac­cessed April 28, 2014 at http://​insected.​arizona.​edu/​insectinfo.​htm.

Ab­bott, J., N. Don­nelly. 2013. "Ophio­gom­phus howei" (On-line). IUCN Red List of Threat­ened Species. Ac­cessed March 26, 2014 at http://​www.​iucnredlist.​org/​details/​summary/​15366/​0.

Bradeen, B., D. Boland. 2004. Spa­tial and Tem­po­ral Seg­re­ga­tion Among Six Species of Co­ex­ist­ing Ophio­gom­phus (Odonata: Gom­phi­dae) in the Aroos­t­ook River, Maine. North­east­ern Nat­u­ral­ist, 11: 295-312.

Brunelle, P. 2008. "COSEWIC As­sess­ment and Sta­tus Re­port on the Pygmy Snake­tail Ophio­gom­phus howei in Canada" (On-line). Ac­cessed March 26, 2014 at http://​www.​queticofoundation.​org/​pdf/​namakan_​pygmy_​snaketail.​pdf.

Hamill, S. 2013. "Re­cov­ery Strat­egy for the Pygmy Snake­tail (Ophio­gom­phus howei) in On­tario" (On-line). On­tario Re­cov­ery Strat­egy Se­ries. Ac­cessed March 26, 2014 at http://​www.​mnr.​gov.​on.​ca/​stdprodconsume/​groups/​lr/@​mnr/@​species/​documents/​document/​stdprod_​099158.​pdf.

Ham­mond, G. 2014. "BioKIDS" (On-line). Anisoptera. Ac­cessed April 23, 2014 at http://​www.​biokids.​umich.​edu/​critters/​Anisoptera/​.

Har­ris, W., D. For­man, R. Bat­tell, M. Bat­tell, A. Nel­son, P. Brain. 2011. Odonata colour: more than meets the eye?. In­ter­na­tional Jour­nal of Odona­tol­ogy, 14: 281-289. Ac­cessed April 23, 2014 at http://​dx.​doi.​org/​10.​1080/​13887890.​2011.​623981.

Kennedy, J., H. White III. 1979. De­scrip­tion of the Nymph of Ophio­gom­phus howei (Odonata: Gom­phi­dae). Proc. En­to­mol. Soc. Wash., 81: 64-69.

Lee, Y. 2009. "Spe­cial an­i­mal ab­stract for Ophio­gom­phus howei (pygmy snake­tail)" (On-line). Ac­cessed March 26, 2014 at http://​mnfi.​anr.​msu.​edu/​abstracts/​zoology/​Ophiogomphus_​howei.​pdf.

Ten­nessen, K. 1993. New Dis­tri­b­u­tion Records for Ophio­gom­phus howei (Odonata: Gom­phi­dae). Great Lakes En­to­mol­o­gist, 26: 245.