Fly

Quick Take

• Flies are secretly the planet's second-most important pollinators, a fact that most people have no idea about. Discover their pollination role →
• Maggots have a surprising medical history that most people would never expect from a household pest. See the maggot medicine facts →
• What you think of as a 'fly' might actually belong to over a dozen distinct groups, and some of those groups share almost nothing in common. Explore the 16+ fly groups →
• There's one simple household step that does more to eliminate flies than traps or sprays, and most people skip it entirely. Find the top prevention step →

Although flies so often have an antagonistic relationship with humans, serving as an annoyance or potential carriers of disease, these insects also play many important ecological roles.

They are the second most common pollinators, behind only bees. They help to keep the environment free of decomposing animal flesh. And as a common subject of genetic research, they also help to advance the frontiers of human knowledge.

5 Incredible Fly Facts

• The evolutionary history of these insects dates back some 240 million years in the fossil record.
• These insects rub their legs together to keep them clean. The bristles on the legs are important sensory organs that can taste the food they land on.
• The maggots, which feed on decomposing tissue, have historically been used by humans to clean wounds.
• These insects undergo four different life stages. The first stage, the egg, typically lasts eight to 24 hours, though this can vary depending on temperature. After hatching, the insect enters a prolonged larval stage in which it goes through a few different molting periods over the course of several days or weeks. The third stage, the pupa, is an intermediate form between larva and adult. It lasts an average of five days. The final adult phase primarily is dedicated to reproduction.
• The insect’s lifespan lasts only a few weeks. However, in this short time, it is highly reproductively active. A single female can lay up to 500 eggs in her lifetime, deposited in several batches of around 75 to 150 eggs each.

Evolution and Origins

The origins of insects date back to the Devonian period, about 400 million years ago, with the Carboniferous period later saw a major radiation of winged insects. Flies specifically belong to the order Diptera, derived from the Greek meaning ‘two-winged.’ Dipterans have one pair of functional wings and one pair of reduced halteres, which serve as balance organs during flight.

The evolution of Diptera is linked to the development of flowering plants, as flies played a crucial role in pollination. Over time, many species of flies have adapted to different environments and food sources, resulting in a diverse group that includes mosquitoes, houseflies, fruit flies, and many others.

Insects, including Dipterans, underwent significant evolution and diversification during the Mesozoic era, resulting in the wide variety of species we see today. Diptera has adapted to many habitats and feeding behaviors; some species are predators, parasites, and decomposers, while others are important pollinators.

One important factor in Dipteran evolution is the development of mouthparts. Many flies have evolved specialized mouthparts to feed on nectar, blood, or other specific food sources. This has allowed them to occupy different ecological niches and adapt to a variety of environments.

Species, Types, and Scientific Names

Flies belong to the order Diptera (meaning two-winged in Greek). This order contains an astonishing variety. More than 160,000 species have been described so far, but there could be a million or more in total.

House, horse, and blow flies are obvious examples, but many people may not know that mosquitoes, midges, and gnats are also members of the same order.

Here is a list of the major groups:

• House and dung flies – Muscoidea
• Blow and flesh flies – Oestroidea
• Marsh flies – Acalyptratae
• Louse flies – Hippoboscoidea
• Hoverflies - Syrphoidea
• Flat-footed flies – Phoroidea
• Dance flies – Empidoidea
• Robber and bee flies – Asiloidea
• Horse and snipe flies – Tabanomorpha
• Stink flies – Xylophagomorpha
• Soldier flies – Stratiomyomorpha
• Crane flies – Tipuloidea
• Drain and sand flies – Psychodomorpha
• Mosquitoes – Culicomorpha
• Gnats – Bibionomorpha
• Midges – Blephariceromorpha

Appearance

The order Diptera comes in so many shapes and sizes that it is difficult to say anything precise about it, but the one trait that unites all of them is the dual-wing structure. The first pair of wings is used for flight, while the second reduced pair is used primarily for balance and maneuverability.

Other important features include two large compound eyes, claws or pads that enable them to stick to smooth surfaces, and complex mouthparts designed for some combination of sucking, lapping, and piercing flesh or plant material. Most species in this order measure less than an inch long.

The largest species is the South American fly, Gauromydas heros, which can measure up to 2.8 inches in body length.

Habitat

Flies can be found in a wide variety of habitats, from tropical rainforests to arid deserts. Some species are adapted to specific environments, while others are more generalist and can be found in many different types of habitats.

These insects are found in almost every single ecosystem and habitat on the planet, including even Antarctica. They pose the greatest danger to human health in warm and tropical regions.

Some common habitats for flies include:

• Forests: Many species of flies, including some of the larger species, can be found in forests, where they feed on nectar, fruits, and other organic matter.
• Grasslands: Grasslands provide habitats for many species of flies, including some of the most common types such as houseflies and horseflies. They feed on a variety of plant and animal matter, including nectar, feces, and carrion.
• Deserts: Some species of flies have adapted to the harsh conditions of deserts, where they feed on a variety of resources, including nectar, plants, and small insects.
• Agricultural areas: Agricultural areas provide habitats for many species of flies, including those that feed on crops, livestock, and other agricultural products. Some species of flies, such as fruit flies, are specially adapted to feed on ripe fruits.
• Urban areas: Many species of flies, including houseflies and blowflies, have adapted to urban environments, where they feed on human food waste and other organic matter.
• Aquatic habitats: Some species of flies, such as mosquitoes and midges, have adapted to live in aquatic habitats, where they feed on algae, aquatic plants, and other organic matter.

The specific habitat requirements for different species of flies vary, and many species can adapt to new habitats as they become available. However, all flies require some type of organic matter, such as food or breeding sites, to survive and reproduce.

Diet

These insects have adapted all kinds of feeding strategies. They can be herbivorous, carnivorous, scavengers, decomposers, and even parasites. Most species have evolved to consume decaying organic matter from fruits, vegetables, meat, and even feces.

Mosquitoes, tsetse flies, and many other types survive by feeding on the blood of vertebrate animals, while other species feed directly on the flesh.

Prevention

The best way to prevent these insects in the first place is to eliminate all sources of decaying food matter (including both human and pet food) around the home. Proper food storage and regular cleaning are necessities for maintaining a fly-free environment.

If you want to get rid of the insects that have already entered your home, then you should invest in proper traps, electric insect zappers, and sprays. Flies also appear to have an aversion to strong herbs such as mint, lavender, and bay leaves.

Keep your doors and windows closed as often as possible and try to eliminate or cover up any holes where they can get in.