Crane Fly Morphology

Morphological terminology follows that of Alexander and Byers (1981).

Crane flies are characterized by their elongate bodies, a pair of narrow wings and long, slender legs.

Gnophomyia tristissma, by Lew Scharpf	Erioptera sp., by Tom Murray	Pilaria sp., by Sasha Azevedo

Tipula furca, by Tom Murray	Epiphragma solatrix, by Steve Scott

Neocladula delicatula, by Stephen Cresswell	Tipula sayi, by Gary Kessler

Nephrotoma ferruginea, by Philip Penketh

 

Crane flies can be distinguished from all other true flies by the V-shaped transverse suture on the dorsal part of the meso-thorax, and by the absence of ocelli.

Dolichopeza sp., by Gaga Lin

 

The body length of crane flies from the front of the head to the tip of the abdomen varies depending upon species. In North America the body sizes vary from 2 mm in Tasiocera ursina, to about 55 mm in Holorusia hespera and 60 mm in the female of Leptotarsus (Longurio) testaceus.

Tasiocera ursina, male	Holorusia hespera, female	Leptotarsus testaceus, female

Head

The head of crane flies is composed of the large compound eyes, the long antennae, and the rostrum which bears the mouthparts.

 

Tipula hirsuta, by Jay Cossey	Pedicia albivitta, by Jean-René Bibeau

 

The compound eyes are large, equal size in both sexes in most species, and usually occupy most of the surface of the head. They are usually glabrous but with short erect hairs in the tribe Pediciini.

The antennae are composed of a cylindrical scape, a subspherical pedicel and 3 (Chionea) to 37 (Gynoplistia) flagellum segments (flagellomeres), commonly 11 in Tipulinae and 12-14 in Limoniinae in the Nearctic Region.

Tipula oleracea Head, by Frank Koehler

 

Limonia annulata Head, by Tom Murray

 

Tipula sp., by Mark Plonsky	Tipula sp., by Gayle and Jeanell Strickland	Chionea valga, by Tom Murray	Gonomyia sp., by Ling-Chu Lin

 

The antennae are generally short to moderate in length, but are often extremely long in male of certain species of Megistocera, Polymera, and Hexatoma.

 

Megistocera fuscana, male	Hexatoma cinerea, male	Polymera sp., male

 

The flagellomeres are usually simple and unmodified but are branched in species of Ctenophora, Limonia (Idioglochina), and Limonia (Rhipidia).

Ctenophora sp., by Ling-Chu Lin	Limonia (Idioglochina) sp., by Gaga Lin	Limonia (Rhipidia) sp., by Gaga Lin

 

The rostrum is conspicuous and often extended into a small projection called nasus in flies of the subfamily Tipulinae. The rostrum is small and inconspicuous in Limoniinae, but greatly elongated in species of Limonia (Geranomyia), Elephantomyia, and Taxorhina. Mouthparts have a pair of four-segmented maxillary palpus. The palpi are short in Limoniinae and longer in Tipulinae.

Nephrotoma alterna, by Gayle and Jeanell Strickland	Dicranoptycha elsa, by Gayle and Jeanell Strickland

 

Elephantomyia westwoodi, by Tom Murray	Limonia (Geranomyia) sp., by Lew Scharpf	Toxorhina magna, by Brian Womble

 

Thorax

The thorax is dominated by the sclerites of the mesothorax in both dorsal and lateral aspects, with well-developed V-shaped transverse suture on the mesodorsum. Two spiracles are situated in membranous areas on the pleural region. Halter long to very long in the Nearctic species.

 

Tipula dorsimaculata, by Mark Plonsky

 

ABBREVIATIONS AND TERMINOLOGY OF THE CRANE FLY HEAD AND THORAX
HEAD	THORAX	Mesonotum: (including prescutum, scutum, scutellum)
ant: antenna	a bas: anterior basalare	p bas: posterior basalare
flgm: flagellomere	anepm: anepimeron	presct: prescutum
lbl: labella	anepst: anepisternum	prn: pronotum
ped: pedicel	a spr: anterior spiracle	p spr: posterior spiracle
plp: maxillary palp	cerv scl: cervical sclerite	sct: scutum
rst: rostrum	cx: coxa	sctl: scutellum
scp: scape	fem: femur	tib: tibia
	hlt: halter	tro: trochanter
	kepm: katepimeron	trn sut: transverse V suture
	kepst: katepisternum
	mtn: metanotum

 

Wings are normally present, but reduced or lost in a few groups, either in both sexes (Chionea) or in females only. Wing venation is highly variable within families, and are important in taxonomy.

 

Tipula sp., by Gayle and Jeanell Strickland

Dicranoptycha sp., by Gayle and Jeanell Strickland

Pilaria sp., by Gayle and Jeanell Strickland

 

ABBREVIATIONS AND TERMINOLOGY USED TO DESCRIBE THE CRANE FLY WING
A1, A2: branches of anal veins	m1, m2, m3: medial cells
C: costa	M1, M2, M3: branches of media
CuA: anterior branch of cubitus	R: radius
CuA1, CuA2: branches of cubitus	R1+2, R3, R4+5: branches of radius
d: discal cell (1st m2 cell)	r-m: radial-medial crossvein
M: media	Rs: radial sector
m-cu: medial-cubital crossvein	Sc: subcosta
m-m: medial crossvein	Sc2: branch of subcosta

 

Each leg consists of coxa (plural: coxae), trochanter, femur (pl. femora), tibia (pl. tibiae), and tarsus (pl. tarsi). Tibiae has zero to two terminal spurs. All crane flies have five tarsal segments (tarsomeres), and tarsal claws either simple or variously toothed.

 

Chionea sp., by John Haarstad

Abdomen

Abdomen is long and slender and with nine evident segments. The apex of abdomen in male enlarged into a club-shaped hypopygium, in female extended into elongate, acutely pointed ovipositor. They can be sexed visually in the field by these two characters.

 

Nephrotoma alterna male, by Gayle and Jeanell Strickland	Nephrotoma alterna female, by Gayle and Jeanell Strickland

 

Dicranoptycha elsa female, by Gayle and Jeanell Strickland	Dicranoptycha elsa male, by Gayle and Jeanell strickland

 

The genitalia of crane flies as a group are diverse greatly. Various authors have attempted to study these characters and proposed independently for the terminology of the reproductive apparatus. The terminology used here for the male and female genitalia, and for the identification keys follow that of Alexander and Byers (1981).

 

Tipula disjuncta male, by Gayle and Jeanell Strickland

Tipula sp. female, by Gayle and Jeanell Strickland