A quick internet search of the term "Crane Fly" generates a lengthy list of pest control articles,
drawing readers in with DIY solutions to rid innocent homeowners of the horrible beasts. Largely considered a scourge because of their larval propensity for munching on grass and crop roots, Crane Flies are a harmless Diptera Insect with little influence on human life or ecological systems. Hypothesized to have been carried over from Europe on ships transferring vegetables, Crane Flies thrived on a continent where predators were unaccustomed to them as an invasive species. They are now a common species across North America, with sources citing anywhere between fourteen and sixteen hundred species on this side of the Atlantic alone. In fact, the Crane Fly family, Tipuldae, is one of the largest of the Order Diptera (Triplehorn 2005). 
Diptera insects are characterized by one set of wings, sucking mouthparts,
stubby hindwings called “halteres,” and complete metamorphosis. This metamorphosis occurs from a worm-like larva stage. Crane flies fulfill all of the Diptera characteristics (Borrow 1981); they are often said to resemble overgrown mosquitos or daddy long leg that have wings. This resemblance to mosquitoes have led some to believe that they are or feed on mosquitoes, but neither of these things are true. As an adult, they possess long, spindly legs and two wings that are typically opaque or patterned. They occur in a range of sizes; the largest recorded Crane Fly, Holorusia grandis, was found in the Western United States with a body length of thirty-five millimeters and a wingspan of body seventy millimeters (Thomas 2008). 
The Crane Fly life cycle begins semi-aquatically, although adults
can be found almost anywhere, including inside houses. The eggs are hatched in damp soil and the larvae feed on decaying or living plants in wet areas- soil or bodies of water- surrounded by dense vegetation (Thomas 2008). The adults’ freedom to roam is associated with their lack of dietary requirements; although some experts hypothesize that certain species drink nectar because of observed probosci, general consensus dictates that they do not eat at all, but survive long enough off of the fat stores from their larval stage to reproduce and then die. The adult Crane Fly life span is only ten to fifteen days, although the females can produce anywhere between two and three hundred eggs in a mere twenty-four hours. They do not, in any way, feed off of or even bite humans (Triplehorn 2005).
http://bugoftheweek.com/blog/2014/6/9/a-case-of-mistaken-identity-crane-flies-family-tipulidae
In both their larval and adult stages, crane flies act as food for birds, mammals, spiders, fish,
and other insects. Their eating controls vegetative populations. Because of their taste for green things, they are considered domestic and agricultural pests, and often prompt the use of insecticides, which can be exceedingly damaging to ecosystems. Additionally, drying out soils by halting irrigation destroys the ideal pupating conditions for Crane Flies, hypothetically limiting their population size (Merchant 2016).
A recent National Geographic article hypothesized about the effect that natural weather phenomena from climate change
might have on Crane Fly populations. Like the limited irrigation strategy, rising temperatures and associated droughts may make Crane Fly reproduction more difficult, specifically finding the ideal conditions for egg hatching. Simultaneously, however, climate change phenomena have caused increased precipitation in many climates. In 2016, the United Kingdom saw a Crane Fly population boom because of uncommonly wet conditions, and extreme weather events are only predicted to increase. John Kramer, co-organizer of the National Cranefly Recording Scheme says, “Increased Energy produces increased evaporation and therefore rainfall [although one would expect this to aid semi-aquatic insect species,]... larvae might get washed out to sea in rivers, or move to the soil to get more oxygen and therefore get eaten by birds (Greshko 2016).” Research will be important to predict how climate change may impact Crane Fly and related insect populations.
References
- Greshko, Micheal. (2016) “U.K. Braces for a Massive Explosion of Flies.” National Geographic.
- Borror, D. (1981) Borror Introduction to the Study of Insects. CBS College Publishing
- Merchant, M. (2016) “Crane flies, not mosquitoes.” Agrilife Extension.
- Thomas, B. (2008) “Crane Flies.” Loyala center for Environmental Communication.
- Triplehorn, C. (2005). Borror and DeLong’s Introduction to the Study of Insects. Brooks/Cole.
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