Hoverfly

Hoverflies, also called flower flies or syrphids, are interesting insects that belong to the family Syrphidae. They are often seen hovering or feeding at flowers. The adults of many species eat nectar and pollen, while the larvae, also known as maggots, eat many different foods. Some larvae eat decaying plant and animal matter, while others eat insects like aphids, thrips, and other pests that harm plants.

Because some hoverfly larvae eat aphids, which are pests for crops, these insects are very important for nature and farming. The larvae can help control pest populations naturally, and the adults help by pollinating flowers.

There are about 6,000 species of hoverflies found all around the world, on every continent except Antarctica. Even though they look like stinging wasps and bees to scare away predators, hoverflies are harmless to most mammals. Their ability to hover in one spot in the air is a special way they find food or look for places to lay their eggs.

Description

Hoverflies come in many different sizes. Some are very small, like Paragus tibialis, which is only 3–5 mm long. Others, like Criorhina nigriventris, can be up to 20.6 mm long. They can look very different too — some are slim and thin, while others are big and hairy with yellow and black bodies. All hoverflies have just one pair of wings. The other pair acts like balancing organs.

Many hoverflies have bright colors, like spots and stripes. These colors make them look like wasps or bees. This helps protect them from birds. Even though they look like stinging insects, hoverflies are harmless to humans. Adult hoverflies mostly eat nectar and pollen from flowers. This is why they are often seen hovering around them.

Reproduction and life cycle

Hoverfly maggots, also called larvae, eat different foods from the adults. Some maggots eat decaying plants and animals, while others eat tiny insects like aphids and thrips that harm crops. These predatory maggots help farmers and gardeners by controlling pest insects naturally.

A famous example is the rat-tailed maggot from the drone fly. It lives in dirty water and has a long breathing tube at its end. These maggots are sometimes used for ice fishing. Very rarely, hoverfly maggots can accidentally get into food.

Evolution

The oldest fossils of hoverflies are from the Eocene period. They have been found in places like the Florissant Formation, Green River Formation, and Baltic amber. Scientists also found an ancient group called Prosyrphus in Late Cretaceous Burmese amber. These fossils show us how hoverflies have changed over millions of years.

Main article: Syrphidae

Distribution and habitat

Hoverflies live almost everywhere except in extreme deserts, the far north tundra, and Antarctica. Some hoverflies live in water, and others live on land near plants or flowers. Many hoverflies visit flowers for food, where they drink nectar and collect pollen.

Some hoverflies prefer special places. For example, the American hoverfly is common in North America, and the common hoverfly is found in Australia and New Zealand. Some hoverflies live inside nests, like in bumblebee or ant nests, while others are found in decaying plant material.

Pollination

Hoverflies help plants grow by moving pollen from flower to flower. They are very important for many plants, both wild and on farms. They are the second most important pollinators after wild bees. Even though bees can carry more pollen, hoverflies visit flowers more often.

Hoverflies like different kinds of flowers. Some hoverflies visit many types of plants, while others like only a few. Many hoverflies are attracted to white and yellow flowers. They can find these flowers by their smell and by looking at them. Some orchids trick hoverflies into helping them by smelling like small pests or by being yellow.

Systematics

Main article: Genera of Syrphidae

Hoverflies are a type of fly in the family Syrphidae. There are many kinds of hoverflies. Scientists have studied them and given each group a name. This helps us learn how these flies are related. Hoverflies are important because they help plants grow by spreading pollen and they keep numbers of pest insects down.

Relationship with humans

Hoverflies, also called adult syrphid flies, help plants by spreading pollen when they eat nectar. Many hoverfly babies eat pests like aphids and leafhoppers. This helps control pests naturally, which is called biocontrol. Gardeners plant flowers such as Alyssum spp., Iberis umbellata, statice, buckwheat, chamomile, parsley, and yarrow to bring in these useful insects.

Some hoverfly babies live in wet places like manure and compost, where they help keep things clean. The island of Runmarö in the Baltic Sea is a special home for many kinds of hoverflies.

Identification guides

Several books can help you identify hoverflies. One useful guide is "Field Guide to the Flower Flies of Northeastern North America" by Skevington and others, which covers many species in that region ISBN 9780691189406. Another guide, "British Hoverflies An Illustrated Identification Guide" by Stubbs and Falk, includes many species and helps with identification using detailed keys and illustrations ISBN 1-899935-05-3.

Additional resources include "Hoverflies of Northwest Europe: Identification Keys to the Syrphidae" by van Veen, and a key to the genera of Nearctic Syrphidae by Miranda and others doi:10.3752/cjai.2013.23. For those interested in hoverflies of Britain and North-west Europe, "Hoverflies of Britain and North-west Europe: A photographic guide" by Bot and Van de Meutter offers many photographs to aid identification ISBN 978-1-3994-0245-3].

Regional lists

Here are some lists of hoverfly species from different places:

• List of hoverfly species of Great Britain
• List of the Syrphidae of Ireland
• List of flower flies of New Zealand
• List of the flower flies of North America
• Syrphidae of New York State