Article - The River Blog

What’s flying tonight?

Author: Jane Skilling
Categories: Uncategorised

There are over 2500 different moths in Britain, roughly 800 macro [larger] and the remainder micro [smaller]. Of these about 1950 species have been recorded in Yorkshire.

People often ask the difference between a moth and a butterfly – the answer sadly is not exactly clear cut!!

Some pointers: –

  • Most moths fly at night, but some fly during the day; the reverse is true of butterflies.
  • Most moths rest with their wings folded, most butterflies with them open – to catch the warmth of the sun.
  • Butterflies have clubbed antennae – little bobbles on the end.
  • Male moths have feathered antennae – to ‘smell’ the pheromone [hormone] emitted by the female.
  • Some female moths do not have wings; once emerged from the pupa, they stay in the same place to attract a male.
  • Many moths do not feed after emerging as an adult and have no feeding apparatus.

There are many ways which people can observe or attract moths. The few day-flying species are relatively easy to observe in the correct habitat. More species start flying during the late evening period before it gets dark; they can be attracted by UV light or sugared ropes identified and then released. Just like butterflies they like buddleia, blossoms etc……

Lifecycle of a Moth

The length of time for each stage of the lifecycle depends on the species of moth. Some can complete more than one generation in a single season, but some may remain as larva for several years. Different moths spend the winter at different stages too. Many species have one generation per year and over-winter as the pupa. For these: the 52 weeks are apportioned approximately:

  4 weeks as an adult,

  1 week as an egg,

  3 weeks as a caterpillar, and

  44 weeks as a pupa.

Moth Eggs

Eggs come in an incredible variety of shapes, sizes and markings. Those that are going to hatch out within a week or two are often laid on a leaf, some on the upper side of the leaf and some on the underside; they may be laid singly, in pairs or in a large batch depending on the species. A few species drop their eggs onto grasses when in flight. Many species that overwinter as eggs lay them on the trunk, branch or twig of a tree and often close to a bud.

The Caterpillar or Larva

Most caterpillars have 3 pairs of true legs and with a few exceptions up to 5 pairs of prolegs or claspers. The true legs are segmented with joints and become the walking legs of the adult moth. As a caterpillar grows in size it becomes too large for its skin, which it sheds – typically 4 times, before it changes into a chrysalis [pupa]. The stages are called instars.

The Chrysalis or Pupa

When a caterpillar is fully grown it usually changes colour when about to change into a chrysalis or pupa. This stage marks one of the most dramatic changes in the development of an insect. The pupal case is developed under the caterpillar’s skin, which softens and splits to reveal the pupal case beneath. When they are ready to pupate, the caterpillar will look for a suitable place to complete this part of its lifecycle which may be on a plant or tree, under leaf and other litter on the ground or in may cases under the earth.

The Adult Moth [Imago]

Emergence from the pupa usually happens at night because while the wings are drying the moth cannot take evasive action from predators. The emergence may take a couple of hours – quicker on a warm night. The wings when the insect emerges are soft but are pumped with a fluid to become more rigid. They need no training to learn to fly!!

You can see a moth emerging here

and you can also see the magnificent feathered antennae.

Here are some websites with pictures of almost every moth found in Britain, as well as sites where you can find out what is on the wing ‘at the moment’.

To help identify a moth you have found go to:

 ‘Flying tonight’

To find out what is flying ‘at the moment’:

[has illustrations]

Written by a Holmfirth Moth-er




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