Types of Flying Insects

Insects are a group of animals with maximum diversity. It is estimated that there are about 6 - 10 million species, some of which are not identified as yet. Insects belong to the phylum Arthropoda and class Insecta or Hexapoda. Like other arthropods, insects have a hard exoskeleton (no endoskeleton), a segmented body (head, thorax and abdomen) and jointed appendages. Some characteristic features of insects are compound eyes, two antennae, breathing through spiracles and presence of one or two pairs of wings (except in some species). The wings (if present) and legs are attached to the thorax region. Let's discuss in brief about flying insects, their types and identification.

Types of Flying Insects

The evolution of wings is a controversial topic; some researchers claim that wings are evolved from gills, whereas 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. spider). 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 the insects belonging to Apterogyta and Pterogyta is that, the former subclass do not undergo metamorphosis; whereas, the latter have 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 types of flying insects along with the orders to which they belong.

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, in areas where there is availability of fresh water. Since the wings of these insects cannot be folded, they are referred to as 'primitive winged' insects. About 5000 insect species are identified under this order.

Order Plecoptera: Insects belonging to the order Plecoptera include the stoneflies. These insects are believed to be one of the most primitive species. The wings are membranous and are characterized by a complex venation pattern. They are aquatic in habitat and undergo metamorphosis without the pupal stage. There are about 3000 species of insects in this order.

Order Orthoptera: Majority of the herbivorous insects belong to the order Orthoptera, for example, grasshopper, locusts and crickets. They have complete metamorphosis and are well-known for their propelling ability; more than 20 times their body length in one jump. They are found in terrestrial habitats, and more than 20,000 insect species are identified under this order.

Order Dictyoptera: The order Dictyoptera include insects that have leathery wings and chewing mouthparts, for example, cockroach and praying mantis. They are found universally; however, some species are strictly terrestrial. About 6000 species are identified in this order.

Order Phasmida: The stick and leaf insects belong to the order Phasmida. They have incomplete metamorphosis and can be easily identified by their camouflage. 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 in this order.

Order Grylloblatodea: Insects belonging to this order are ice bugs and rock crawlers. They are considered as 'living fossils', due to their similarity with their ancient ancestors. They prefer extreme habitats (located at high altitude); only 25 species are found in this order.

Order Hemiptera: Insects belonging to the order Hemiptera are characterized by their piercing and sucking mouthparts, and half membranous fore wings, for example, aphids and water bugs. This order include highly diverse insects; some are adapted to aquatic habitats, whereas some are terrestrial. About 70,000 species are identified in this order.

Order Lepidoptera: The order Lepidoptera is the second largest order of insects and includes more than 100,000 species. Insects belonging to this order are moths and butterflies. 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 is one of the largest, comprising more than 350,000 insect species. Beetles and fireflies belong to this order. These insects are characterized by their hardened and thickened fore wings, that cover the entire body. They are aquatic or terrestrial and feed on plants and/or other insects.

Order Diptera: The order Diptera, also known as true flies, include mosquitoes, gnats and midges. Their characteristic feature is the presence of two pairs of wings; out of which only the forewings are functional, the hindwings are replaced by modified wings, called halteres. More than 100,000 species are identified in 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, including about 100,000 species. Hymenoptera include insects such as ants, horntails, bees and wasps. The two pairs of wings, forewings and hindwings 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 are the termites. 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 furnitures. There are over 3000 insect species in this order.

These are some of the flying insect types, which are found commonly. Some insects cause destruction to the crops, and are identified as pests; whereas, many insects are referred to as 'farmer's friend', as they feed on other destructive pests, indirectly increasing the crop yield. Insects play a major role in the food chain and overall functioning of an ecosystem.