Description
There are many species of moths that attack a variety of
textiles. This page will cover: the Common Clothes Moth, the Case Bearing Clothes Moth and the Brown House Moth.
A small insect 4-7mm in size with pale straw coloured forewings
with no pattern, is an indoor insect common throughout Britain and
most of the world, with the exception of the tropics.
Reasonably cold-hardy and associated with many natural products of
animal origin, especially woven fibres, fur and feather products
and fertilisers. Despite these food preferences, this species
is not a frequent inhabitant of birds’ nests.
Biology and Habitat
The mated, adult female moth tries deliberately to lay her eggs
amongst fibres of a suitable food material for the larvae. The
larvae will emerge at temperatures above 10◦C and almost
immediately start to spin silk from glands situated below the
head. Sometimes the silk forms a mat or tent but more usually
each larvae constructs a smooth lined tunnel by weaving the silk in
amongst excreta (frass) and particles of substrate. The
resultant camouflaged case with periodic enlargement serves as a
home throughout the larval development period, the caterpillar
emerging at night to feed and returning to the safety of its tunnel
during the day. A normal number of 5 moults occur prior to
pupation but poor quality food materials and low temperatures can
extend the number of moultings up to as many as 40. The pupa
is formed inside the final larval case and remains concealed until
shortly before the emergence of the adult moth. Then the fully
formed adult within the pupal case wriggles free of the silk tunnel
and emerges.
The female moth is quite sedentary but the males do fly on
occasions. If is the male that exhibits most excitement in the
pre-mating action but in most other circumstances both sexes move
by running or occasionally jumping. It is characteristic of
this species for the adults to be seen “scuttling” in and amongst
the larval food material. The adults are unable to feed,
having greatly reduced mouth parts and without the soiled sucking
proboscis of the larger Lepidoptera.
The breeding temperature range is from around 10◦C to 33◦C and
around 70% humidity seems ideal for this species. Mainly
depending on temperature, periods of development can range from 1
to 5 weeks for the eggs, 2 to 7 months for the larvae and 1.5 to 7
weeks for the pupal stage. The quality of food material has an
effect on development period and the size of the resultant adult
moths.
Importance
Clothes Moths neither carry germs nor do they spread disease
hence their presence does not constitute a risk to
health. However, the activities of the larvae will cause
damage and indeed ruin carpets, animal furs and leathers.
Control
These moths are often indicative of poor hygiene
conditions. The area should be thoroughly cleaned and vacuumed
to remove any eggs, larvae and pupae. Residual sprays may be
applied to the infested areas. Care should be taken when using
any insecticide spray, the advice and directions for use should be
carefully followed.
Safety
Not all insecticides are safe for use indoors, particularly
where food is present or on certain materials/surfaces. To
protect yourself and others and to minimise damage to the
environment ALWAYS READ AND FOLLOW THE APPLICATION AND USE
INSTRUCTIONS PRINTED ON THE CONTAINER.
This species is similar in appearance to the common clothes
moth, with the larvae feeding on particles of woollen clothing,
furniture fillings, furs and carpets. The larvae spin a silken
case around themselves, this case is carried around when the larvae
move (hence the name) and the damage is solely caused by the larvae
feeding. The case is off white in colour and is approximately 5mm
long. Control is similar to that of the clothes moth.
The adult moth can grow to a maximum of 8mm and is uniformly
shiny gold flecked with dark brown. It is common in the UK
and feeds on dry animal protein, including feathers, hair and wool.
The adult lays eggs singly, scattered very near to a food source on
which the larvae will feed 2-4 weeks later (depending on the
temperature) the larvae hatch and can take between 2-5 months to
develop through to the pupal stage. The pupal stage is formed
inside a tough silken cocoon and 2-8 weeks later the adult moth
emerges. The adults live between 1-4 weeks. Control is similar
to that of the clothes moth.
