Types of Flying Insects

Insects are a group of organisms having maximum diversity. It is estimated that about 6 - 10 million species of insects exist on earth, some of which are not identified as yet. They belong to the phylum Arthropoda and class Insecta or Hexapoda. Like other arthropods, they have a hard exoskeleton (no endoskeleton), a segmented body (head, thorax, and abdomen) and jointed appendages. Characteristic features of insects are compound eyes, two antennae, presence of one or two pairs of wings (except for some species), and breathing through spiracles. The wings (if present) and legs are attached to the thoracic region.

Different Types of Flying Insects

The evolution of winged insects is a controversial topic. While some researchers claim that their wings evolved from gills, many are of the opinion that they are paranotal in origin. Though majority of the insects possess wings (e.g., butterfly), some primitive species are wingless (e.g., silverfish). Thus, based on the presence or absence of wings, the class Insecta is further classified into two subclasses, viz., Apterogyta (wingless insects) and Pterogyta (winged insects).

In addition to wings, another distinguishing feature between Apterogyta and Pterogyta is that insects belonging to the former subclass do not undergo metamorphosis, whereas, the insects of the latter group go through simple (without pupal stage) or complete metamorphosis. In total, there are 25 orders of the subclass Pterogyta or winged insects. Following are some of the familiar flying insect types along with the orders to which they belong and some tips to identify them.

Order Odonata
	The dragonflies and damselflies belong to the order Odonata, which are characterized by the presence of toothed jaws and very large eyes. They are commonly found in tropical climatic conditions, particularly in areas where there is availability of freshwater. Since the wings of these insects cannot be folded, they are referred to as 'primitive winged' insects. About 5,000 insect species are identified under this order.
Order Plecoptera
	Insects belonging to the order Plecoptera include various types of stoneflies. They are classified as some of the most primitive species. The wings are membranous and are characterized by a complex venation pattern. The larvae are aquatic in habitat and undergo metamorphosis without the pupal stage. Hence, adults are mostly found near freshwater bodies. There are about 3,000 species of insects in this order.
Order Orthoptera
	Majority of the herbivorous insects belong to the order Orthoptera. Familiar examples include grasshopper, locusts, and crickets. They have complete metamorphosis and are well-known for their propelling ability. You will be surprised to know that they jump more than 20 times of their body length in one go. They are found in terrestrial habitat and more than 20,000 insect species are identified under this order.
Order Dictyoptera
	The order Dictyoptera includes insects that have leathery wings and chewing mouthparts. For example, cockroach and praying mantis. The term itself means network wings and you can identify insects of this order from the characteristic veins present in the wings. The Dictyoptera insects are found universally and some species are strictly terrestrial. About 6,000 species are identified under this order.
Order Phasmida
	The stick and leaf insects belong to the order Phasmida, also spelled as Phasmatodea. They have incomplete metamorphosis and can be easily identified by their camouflage. Members belonging to this order measure 1 inch in length to as long as a foot. The stick insects, named due their resemblance with stick, are the longest insects in the world. As of now, about 3,000 insects are identified under this order.
Order Hemiptera
	Insects belonging to the order Hemiptera are characterized by their piercing and sucking mouthparts, and half membranous forewings (thick at the base and membranous at the tips). Examples of these insects are hoppers, aphids, and water bugs. This order includes highly diverse insects. While some are adapted to aquatic habitats, others are truly terrestrial. In total, about 70,000 species are identified under this order.
Order Lepidoptera
	The order Lepidoptera is the second largest order of insects and includes more than 100,000 species. Moths and butterflies belong to this insect order. They are characterized by large eyes and scaly wings, in which small scales overlap with each other. Another feature of these insects is the presence of a simple eye, known as ocellus, on the top of each compound eye. They can also be identified by their vibrant colored wings.
Order Coleoptera
	The order Coleoptera represents a large insect group, comprising more than 350,000 insect species. Beetles, glowworms, and fireflies are grouped in this order. These insects are characterized by their hardened and thickened forewings (elytra), which cover the delicate hind wings and the entire body. They may be aquatic or terrestrial in habit. As far as feeding is concerned, they munch plants and/or other insects.
Order Diptera
	The order Diptera, also known as true flies, include mosquitoes, gnats, flesh flies, and midges. Their characteristic feature is the presence of two pairs of wings, of which only the forewings are functional and the hind wings are replaced by modified wings called halteres. Other identifying traits are extra-large compound eyes and sponging or biting mouthparts. More than 100,000 insect species are identified under this order.
Order Hymenoptera
	Hymenoptera, as the name suggests, is an order that encompasses insects with membranous wings. It is the third largest order of class Hexapoda, comprising about 100,000 species. Hymenoptera include insects such as ants, horntail, bees, and wasps. The two pairs of wings (forewings and hind wings) are joined via the hamuli, which are tiny hooks. Hence, at the time of flight, both the wings function in coordination.
Order Isoptera
	The most common species of the order Isoptera is the termite. Tips for identifying these flying insects are a pair of similar length antennae, chewing mouth parts, tapering body, and two pairs of membranous wings. They play a major role in decomposing materials in the forest ecosystem by feeding on dead and decayed plant parts. Some species are identified as pests as they feed on wood furniture. In this order, there are over 3,000 insect species.
Order Trichoptera
	If you come across an insect with silky hair in the wings and body, most likely it is a species of the Trichoptera order. At first glance, it resembles a moth, except for the hairy wings (wings of moths are scaly). Classic example of this insect group is the caddisflies or sedges. The larval stage of these flies are aquatic, while the adults are terrestrial and nocturnal in habit. Under this order, about 12,000 species are classified scientifically.
Order Ephemeroptera
	Mayflies are the only insects belonging to this order of flying insects. The triangular-shaped membranous wings, exceptionally small hind wings, and tail like structures (2 - 3 in number) are the identifying features of mayflies. While resting on the ground, the wings are pointed upwards. The nymph stage of mayflies are aquatic and similar to the adult flies except for absence of wings. Adults live for a very short time, usually 1 - 2 days.

These are some of the flying insect types, which we come across in and around our surroundings. Some insects cause destruction to the crops and are identified as pests. Many of the species are referred to as 'farmer's friend' as they feed on other destructive pests, indirectly increasing the crop yield. In a nutshell, both winged and wingless insects play a major role in the food chain and overall functioning of an ecosystem.