Bug vs Insects
In most of the Western cultures, almost all the insects are known as bugs. Sometimes, it is not just for insects; spiders, scorpions, mites, ticks, centipede, woodlouse…etc are also called as bugs. However, the real meaning for bugs is different in a zoological perspective. Bugs are a group of insects belonging in the Order: Hemiptera. Bugs share most of the other insect features but, they become unique with respect to some other characters.
Bugs
There about 50,000 – 80,000 species of hemipterans but, only around 6,000 species are described. Some members of the hemipterans include aphids, scale insects, tree hoppers, plant louses, true bugs, and mealy bugs. Although, the true bugs could be narrowed down to Suborder: Heteroptera, taxonomically shared other features categorize all the hemipterans as bugs. They have two pairs of membranous wings. Up to about a half of the forewing is thickened from the base. However, there are wingless bugs, and sometimes they have only forewings. They are equipped with piercing and sucking mouthparts, and the rostrum/proboscis is sharp. Their antennae have five segments. The tarsi of the legs is segmented to three parts. Their size could vary between 1 millimetre and 15 centimetres. Above all the features, the mouthparts and semi-hardened wings distinguish the hemipterans from all the other insects. Thus, they can be regarded as a unique group of insects.
Insects
They are the largest group of animals with an expected number of species between six to ten million. So far, there are about 1,000,000 described species of insects. Insects can sustain in almost all the ecosystems due to their extreme adaptability. This extremely higher number of insect species in the world lifts their importance. Some of the very common insects are butterflies, ants, bees, weevils, paddy bugs, crickets, grasshoppers, leaf insects, mosquitoes…etc. They have three specialized segments in the body known as tagma, consisting of the head, thorax, and abdomen. Basically, the head is designed for feeding and sensory functions, thorax mainly for locomotion, and the abdomen functions as mainly for reproduction. There are three pairs of legs originating from the thorax. The head has two compound eyes and two antennae for sensory functions. In the abdomen, anus opens the oviduct and rectum to the exterior (i.e. they have only one opening for defecation and reproduction). Somehow, this thriving group of animals are considered to be the most successful in the Kingdom: Animalia.
What’s the difference between Bug and Insects?
Bugs (Order: Hemiptera) being a group under Class: Insecta, both these two share some similar features. The presence of three pairs of legs, compound eyes, segmented antennae…etc are some of the common features of both bugs and insects. However, bugs become unique for the presence of their characteristic features. Sometimes, the membranous wings could be confused with other insect wings but, the semi-hardened nature divides them from all others. Although, bugs’ piercing and sucking mouthparts could be used to distinguish them from other insects, the mosquitoes also have the same kind of mouth parts. But, along with the characteristic body shape of bugs with their habitats and habits, they are distinct from other insects.