Crane flies are common insects often encountered in homes and gardens, especially during certain seasons. Their large size and long legs frequently lead people to question whether these creatures can cause harm. This article aims to clarify the truth about crane flies and address common concerns regarding their potential to injure humans.
The Harmless Truth
Crane flies do not bite, sting, or transmit diseases to humans. Their mouthparts are not designed for piercing skin or consuming blood, unlike mosquitoes. Most adult crane flies have either greatly reduced mouthparts or none at all.
If adult crane flies feed, they typically consume only nectar or water, primarily to sustain themselves for reproduction. Their adult lifespan is very short, often lasting only a few days to about two weeks, during which their main objective is to mate and lay eggs. Crane flies are non-aggressive and entirely harmless to encounter.
What is a Crane Fly?
Crane flies are slender insects recognized by their long, fragile legs, elongated bodies, and a single pair of smoky, narrow wings. They belong to the insect order Diptera, which includes true flies, and are classified within the family Tipulidae, encompassing over 15,000 described species worldwide. Adults typically measure between 15 mm and 25 mm long, excluding their legs, though some species can be larger.
These insects are commonly found in moist, vegetative habitats, such as areas near water sources, including lakes, streams, and damp soil. Crane flies undergo complete metamorphosis, progressing through egg, larva, pupa, and adult stages. The larval stage, often called “leatherjackets” due to their tough skin, lives in soil or water and feeds on decaying organic matter, plant roots, or sometimes small aquatic insects.
Separating Fact from Fiction
Crane flies are frequently mistaken for giant mosquitoes due to their similar appearance, leading to a common misconception that they bite. However, a key difference is that mosquitoes possess piercing mouthparts for blood feeding, while crane flies do not. Another widespread myth is that crane flies are “mosquito hawks” or prey on mosquitoes.
Adult crane flies do not hunt or consume other insects, including mosquitoes. If a crane fly enters a home, it is usually by accident, often attracted to lights. The most appropriate way to handle them is to gently guide them outside, as they are harmless and will not cause damage.