There are a staggering 27,000 types of insect in the UK. Some can be tricky to tell apart, even for the experts. Here we look at some of our most commonly encountered insect groups and the clues we need to look for to help narrow them down.

What is an insect?

Broadly speaking, invertebrates are animals without a backbone and include multi-legged, hard-bodied minibeasts, known as arthropods, as well as corals, slugs and snails, worms and soft-bodied sea creatures. Arthropods can then be separated into groups including crustaceans (such as crabs and woodlice), spiders and insects.

Happily, insects share a number of characteristics to help you separate them from the crowd:

  • Six legs
  • Three body sections (head, thorax and abdomen)
  • Pair of antennae
  • Exoskeleton
  • Compound eyes
  • Most have wings
  • Three or four stage life cycle (egg, larva or nymphs, pupa and adult)

Insects come in a number of groups, or 'orders', not all of which have representatives here in the UK. Let's explore nine of the more frequently encountered minibeast types and some of their more well-known members.  

Coleoptera - beetles

Key features

biting or chewing mouthparts

hardened wing cases, with wings folded beneath

life cycle: egg -> larva -> pupa -> adult

Not to be confused with bugs (Hemiptera), some of which also have hardened wing cases

Spotlight species: 7-spot ladybird

  • active from early spring to autumn, hibernating through winter, sometimes indoors
  • widespread across the UK in gardens, woodland and grassland habitats feeding on aphids
  • when threatened, extrudes a nasty-tasting yellow substance from its leg joints to put off predators

Diptera - flies

Key features

one set of wings

sucking or piercing mouthparts

life cycle: egg -> larva (maggots) -> pupa -> adult

Not to be confused with sawflies which belong to the same order as bees and wasps (Hymenoptera)

Spotlight species: Daddy longlegs

  • long and ungainly legs and erratic flight pattern
  • emerge as adults from lawns and grassland in late summer and mostly active at night
  • contrary to popular belief, craneflies are not poisonous and cannot bite or sting

Hemiptera - bugs

Key features

piercing and sucking mouthparts

not always with wings

most feed on sap or nectar, but some suck blood

life cycle: egg -> nymphs -> adult

Not to be confused with beetles (Coleoptera) which fold wings beneath a hardened outer set

Spotlight species: Hawthorn shieldbug

  • speckled green and red wing cases with a distinctive green ‘shield’ shape in the centre
  • adults are most active in late summer 
  • feed on the ripening berries of hawthorn, rowan and cotoneaster and often found in gardens

Lepidoptera - butterflies and moths

Key features

large, powdery wings (although some female moths go without)

long 'proboscis' or feeding tube

feed on nectar, juices or animal dung (although many adult moths do not feed at all)

life cycle: egg -> larva (caterpillar) -> pupa -> adult

Not to be confused with other large flying insects - some moths cleverly mimic hornets and wasps

Spotlight species: small white butterfly

  • faded black wing tips and one or two small spots
  • known as 'cabbage whites' after their favourite caterpillar food plants

Dermaptera - earwigs

Key features

rear-end pincers, used for defence or to capture prey but harmless to humans

flat, elongated bodies for working into crevices

chestnut brown colouring

life cycle: egg -> nymphs -> adult

Spotlight species: common earwig

  • most active at night, but can be found beneath decaying wood, in leaf litter or on flowering plants
  • pincers curved in males and almost straight in females
  • mothers care for their eggs and young

Orthoptera - grasshoppers and crickets

Key features

long, folded hind legs

create sounds by rubbing wings (crickets) or legs (grasshoppers) together

life cycle: egg -> nymphs -> adult

Crickets and grasshoppers are often confused, but crickets generally have antennae longer than their bodies

Spotlight species: meadow grasshopper

  • feeds on long grasses through the summer
  • males have longer wings than females
  • appears in a variety of colours, including green, brown and bright pink

Hymenoptera - bees, wasps and ants

Key features

two sets of wings, the front longer than the back

some species live in colonies

females of some species can sting

life cycle: egg -> larva -> adult

Not to be confused with some flies, such as hoverflies and bee-flies, which disguise themselves as stinging insects

Spotlight species: common carder bee

  • ginger-coloured bumblebee common in gardens
  • workers become active in spring, but only queens overwinter to form new colonies 
  • builds nests in grassy tussocks

Odonata - dragonflies and damselflies

Key features

large eyes for hunting down prey

elongated bodies

two sets of long, translucent wings

Not to be confused with mayflies which are much shorter lived and are not voracious hunters

Spotlight species: common blue damselfly

  • active throughout spring and summer, usually near a source of water, but often seen in gardens
  • males are bright blue and black, females a paler grey
  • unlike dragonflies, damsels rest with wings alongside their bodies

Ephemeroptera - mayflies

Key features

three long, trailing tail filaments

mostly two sets of translucent wings, the front larger than the back

always found near water and famously short lived

Not to be confused with damselflies or dragonflies as mayflies don't feed as adults

Spotlight species: common mayfly

  • dark spots on the wings and triangular markings along the body
  • breeds in ponds and slow moving water in England
  • contrary to popular belief, this particular species of mayfly can appear at any time over the summer

Insects are incredibly important. They recycle decaying material. They pollinate plants. They feed a huge variety of birds, mammals and other animals. Without them we would be unable to grow food, and much of the other wildlife we treasure would be lost forever.

A single mature oak tree is home to as many as 350 species of insect alone, and mixed, native woodlands support even more. With healthy woodlands come abundant insects and thriving people and wildlife.

Identify minibeasts 

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Discover more about UK insects and their relationships with trees