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.
The Clothes 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.
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.
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.
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.
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.
The Case Bearing Clothes Moth
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 Brown House 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.