Large, gangly insects often resemble oversized mosquitoes, leading to immediate concern. However, these creatures are generally harmless and belong to different insect families than true mosquitoes.
Identifying the Imposters
Several insects are commonly mistaken for large mosquitoes due to their slender bodies and long legs. Crane flies (family Tipulidae) are a common example. These insects have a delicate, elongated body, long, spindly legs, and narrow, transparent wings. Adult crane flies measure between 0.5 to 1.4 inches long, excluding their legs, with some species having a wingspan of up to 3 inches. They often appear in dull colors like brown, black, or pale yellow.
Non-biting midges (family Chironomidae) are another. These delicate flies are generally smaller than crane flies, measuring between 0.2 to 0.5 inches in length. They possess long front legs often held forward from their bodies and have clear, unmarked wings. Non-biting midges can vary in color, appearing light green, pale, tan, or dark brownish-black.
Telling Them Apart from Mosquitoes
Distinguishing them from actual mosquitoes involves several key features. Mosquitoes possess a distinct, needle-like proboscis used for piercing skin and sucking blood. In contrast, crane flies and non-biting midges have short, stubby, or absent mouthparts. Crane flies, for instance, have a snout-like head that ends in a slender bump, and most species lack functional mouthparts for feeding.
Body structure and appendages also provide clues. Mosquitoes often have a more delicate, compact body, usually measuring between 3 to 6 millimeters long, and their wings are covered with distinct scales. Crane flies are noticeably larger and have a more gangly appearance with extremely long, fragile legs that can easily detach. Non-biting midges are generally smaller than crane flies, but like crane flies, they lack scales on their wings.
Antennae and flight patterns offer further distinctions. Male mosquitoes have bushy, feathery antennae, while female antennae are more thread-like. Male non-biting midges also exhibit bushy, feathery antennae, while females have thread-like ones. Crane flies have relatively short and flexible antennae.
When at rest, many mosquitoes hold their hind legs outward and upward, whereas non-biting midges often hold their front legs forward and upward. Mosquitoes produce a characteristic high-pitched buzz when flying, while crane flies often have a clumsy or silent flight, sometimes bumping into objects. Non-biting midges can produce a high-pitched humming sound, especially when swarming.
The Truth About Their Bite
Large mosquito-like insects like crane flies and non-biting midges do not bite humans or animals. Their mouthparts are not adapted for piercing skin or sucking blood, so they do not transmit diseases.
Adult crane flies have a short lifespan, lasting only a few days to a week, primarily for reproduction. Many adult crane fly species do not feed, while others consume nectar or water. Non-biting midges also have short adult lives, focusing on mating. Some adult non-biting midges consume nectar, pollen, or honeydew.
Their Place in the Ecosystem
These insects play important roles in their ecosystems. Crane flies undergo a four-stage life cycle: egg, larva, pupa, and adult. Female crane flies typically lay their eggs in moist soil, often near water sources or in damp lawns. The larvae, commonly known as “leatherjackets,” are typically found in moist soil, decaying vegetation, or aquatic environments.
Crane fly larvae are decomposers, breaking down organic material like decaying plants and leaves, returning nutrients to the soil. Some larvae may feed on grass roots and shoots, but they are generally not considered pests. Adult crane flies, despite their short lifespan, are a food source for animals like bats, birds, lizards, spiders, and other insects.
Non-biting midges also have a four-stage life cycle, with females laying eggs on the surface of water. Their larvae are aquatic, living in mud or sediment at the bottom of water bodies, and feed on suspended organic matter. These larvae, sometimes called “bloodworms” due to their red color, are an important food source for fish and other aquatic wildlife. Adult midges, in turn, provide food for birds and bats. These insects contribute to the transfer of nutrients from aquatic to terrestrial food webs.