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Adults of this small (6-7 mm) gray crane fly are the first species to appear in
the spring, when most vegetation has not yet started growing. They are common
and abundant in the spring in nearly all wooded habitats and open grasslands.
The fall generation is less conspicuous. The larval stages are found in
saturated earth along water edges. There is only one species in this genus found
in North America. This species is wide spread throughout North America, as far
south as the mountains of Central America.*
This specimen was photographed May 15, 2005 near the banks of the DuPage River,
West Branch near Winfield IL.Adult crane flies are sluggish fliers and
are often abundant in moist woodlands and around water, usually
near places where their larval life is spent. They occur mainly
in spring and fall, but species of wingless, snow crane flies
(Chionea) appear in the winter. Adult crane flies are most
active in the cooler part of the day, usually around dusk.
Adult males are more abundant at the beginning of the flight
period while females are more numerous toward the end. Although
individual adults have a relatively short life span of 10 to 15
days, the flight period for each species can last from 25-30
days. The main functions of the adult stage are mating and
egg-laying. Feeding is less important, and probably water is
the most pressing need. Species with elongated rostrum
(Geranomyia, Elephantomyia, Toxorhina) have been reported
visiting flowers, probably for nectar.
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Tipulidae, often called crane flies
in their adult stage, is the largest family of true
flies. Crane flies form a highly diverse group of
insects, both in number of species and in larval
habitats, which extend from aquatic to terrestrial. The
body plan or morphology of crane flies is rather
simple. An elongate body, one pair of narrow wings, and
long, slender legs characterize them. The body size
ranges from 5 to 50 mm and can be described as
mosquito-like. They are often mistaken for mosquitoes,
but they belong to a group of harmless flies and can be
distinguished from all other true flies by the
transverse V-shaped groove on the dorsal part of the
thorax.
In North America, more than 1,500 species of crane flies
have been described and over 300 species are known from
Pennsylvania. This number probably represents only
about two-thirds of the estimated actual number for the
state, and much more precise taxonomic studies are
needed.
Crane flies undergo complete metamorphosis in their
development with a brief egg stage, a relatively long
larval feeding stage, a brief pupal resting stage, and
finally a short adult breeding stage.
Crane flies serve several important roles in the
ecosystem. Most importantly, adult and larval crane
flies are food for many animals such as birds, fish,
frogs, lizards, spiders and other insects. In addition,
the larvae are detritus feeders that break down organic
matter in various habitats such as streams and forest
floors thereby enriching the soil, renewing and
modifying the microhabitat for other invertebrate
species. Some crane flies require special habitat
conditions, and their presence or absence can be used as
an indicator of environmental quality. Fishermen use
larvae of some large crane flies as bait. Several
species of crane flies are important agricultural pests;
their larvae feed on seedlings of field crops and if
abundant can be destructive to lawns, rangelands, rice
fields, and golf courses.
1.
Crane Flies of Pennsylvania |
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