
Description
Order: Lepidoptera ('scale wings')
Characteristics:
Two pairs of well developed membranous
wings, with few cross veins; clothed with
broad scales; generally suctorial mouthparts;
metamorphosis complete with egg, larval,
pupal and adult stages; larvae frequently
have eight pairs of limbs.
Superfamily: Pyraloidea
(family Pyralidae)
Superfamily: Tineoidea
(families Oecophoridae, Tineidae)
Species characteristics:
Family: Pyralidae
Warehouse Moth
(Cacao Moth, Tobacco Moth) (Ephestia
elutella)
12mm wingspan; upper forewing: well
defined, rather sinuate outer band on greybuff
background.
Tropical Warehouse Moth
(Dried Currant Moth) (Ephestia cautella)
12-18mm wingspan; upper forewing: dull
grey-brown; straight dark inner band has
broad pale band along inner edge; outer
band is obscure.
Mediterranean Flour Moth
(Mill Moth/Flour Moth) (Ephestia
kuehniella)
20-25mm wingspan; upper forewing:
oblique irregular inner band spotted or
streaked, lacking pale band along inner edge;
outer band is obscure.
Indian Meal Moth
(Dried Fruit Moth) (Plodia interpunctella)
10-15mm wingspan; upper forewing: inner
third, pale yellowish buff; remainder of wing
bronze-coloured.
Rice Moth (Corcyra cephalonica)
15-25mm wingspan; upper forewing:
uniform pale buff-brown; no distinctive
markings, although veins may be slightly
darkened.
Family: Oecophoridae
Brown House Moth
(Hofmannophila pseudospretella)
15-25mm wingspan; upper forewing: dark
buff-brown with black-brown spots.
White-Shouldered
House Moth (Endrosis sarcitrella)
15-25mm wingspan; upper forewing: buffcoloured
and speckled brown; resembles
Brown house moth, but distinguished by
white scales on head and thorax.
Family: Tineidae
Common Clothes Moth (Tineola
bisselliella)
10-15mm wingspan; upper forewing: pale
ochreous buff, unmarked.
Distribution
Moths can be found in a variety of stored
products. Some species are associated with
goods of vegetable origin, to which they
may be adapted with varying degrees of
specificity, whilst others are associated with
animal products - particularly textiles.
Warehouse Moth
Widely distributed throughout temperate
regions. It is rarely imported except on
products from other temperate areas.
Tropical Warehouse Moth
A tropical or subtropical species which is
frequently found on imported cargoes.
Mediterranean Flour Moth
Originated in Central America but now
cosmopolitan. It is a particular problem in
provender mills, bakeries and occasionally
even in catering premises. One generation is
usually produced, but in warm conditions
adults will be present throughout the year
when there may be 4-6 generations.
Indian Meal Moth
A cosmopolitan species which originated in
South America. It will survive all year round
in warm conditions.
Rice Moth
A tropical species often found in countries
of northern Europe in imported foodstuffs.
In these temperate areas it can survive all
year round in heated stores but usually
produces only one generation.
Brown House Moth/
White-Shouldered House Moth
Both species are cosmopolitan and
widespread on materials of animal or
vegetable origin.
Common Clothes Moth
Common on animal products.
Significance
Moth larvae can cause considerable damage
to stored goods by feeding or by
contamination with their own products, e.g.
webbing and frass. Adult insects are not
responsible for damage as they either feed
on liquid food and water or do not feed at
all. The larval by-products, webbing and
frass, are a particular problem. Webbing can
entirely coat commodities and may be
responsible for blocking machinery and
ducts. The problem is exacerbated when
webbing becomes mixed with frass, food
and general debris.
Warehouse Moth
A major pest of warehouses and, more
recently, retail premises. This species will
infest cereals, fruit, shelled nuts, cocoa
beans, fish, spices and tobacco. In the case
of tobacco, "sweet" varieties are preferred
and entire interveinal leaf areas may be
destroyed. Moth infestations are especially
serious where wheat and flour are stored in
bulk, although they seldom infest goods
which are stored in silos.
Tropical Warehouse Moth
A particular problem in dried fruit and nuts,
although this moth will attack cereals, oil
seeds and chocolate products.
Mediterranean Flour Moth
Larval webbing can cause serious blockages
in provender mills. The larvae eat holes in
sifting silks and may also reach the mill's
finished products.
Indian Meal Moth
Another species which is a particular
problem of the fruit-drying industry. It will
also attack cereals, oil seeds and shelled
nuts. Larval webbing may occasionally
reach problem proportions.
Rice-Moth
This moth will attack grain (especially rice),
oil seeds, cocoa beans, dried fruit, spices and
beverages.
Brown House Moth/
White-Shouldered House Moth
Both species attack a wide variety of
materials including cereals, cereal products,
textiles, leather and cork. The Brown house
moth tends to scavenge whilst the Whiteshouldered
house moth is generally found
infesting food.
Common Clothes Moth
Attacks animal products, for example wool,
fur, skins and leather. Fibres are bitten off
and the loose ends discarded, thus
destroying much more commodity than is
consumed.
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Life-Cycle
Larval development is greatly influenced by
the environmental conditions of temperature
and food supply. The larvae themselves are
unique and readily identifiable: welldeveloped
head; clearly segmented body;
three thoracic segments, each bearing a pair
of five jointed legs; ten abdominal segments:
numbers 3-6 bear false feet (prolegs), the
tips of which are equipped with crochets;
segment ten bears one pair of claspers.
Warehouse Moth
Within 4 days of emergence, the female
produces 100-150 eggs which are laid in
cracks and crevices. These hatch in 10-14
days to give larvae which are creamy white
with dark spots on their sides. They
penetrate food, covering it with webbing as
they feed. In temperate climates larvae pass
through 4-5 moults to attain full growth
when they are 12mm long, whereupon they
will leave the food and wander for 1-3 days,
searching for a dark place in which to spin a
silken cocoon. They may diapause in this
state throughout the winter before pupating
in April or May and emerging as adults in
late spring. Under temperate conditions
development takes from 82-206 days.

Tropical Warehouse Moth
Egg laying commences within 24 days of the
adult's emergence and up to 350 eggs are
laid during the first 4 days. These hatch 3-17
days later. The larvae are dirty white and
may be tinged brown or have purple spots.
At 25°C they will be fully grown in 25 days.
The larvae do not diapause. Pupae develop
in 12-17 days in the vicinity of food, and
breeding is continuous. Where temperatures
are low the moth overwinters as larvae.
Mediterranean Flour Moth
Mating takes place immediately after the
adults emerge. Up to 350 eggs are laid and
these may be stuck to various foods by a
sticky secretion. The eggs hatch in 4-28 days
to give white or pinkish larvae and spin
silken tubes in which they live. After 3-5
moults the larvae are full grown and
15-19mm long.
They then wander away from food and
pupate for 7-16 days in the dark corners of
buildings or machinery. In temperate
climates these moths overwinter as larvae
but, in contrast to other species, usually
remain in the foodstuff.
Indian Meal Moth
Females produce up to 500 greyish-white
eggs which hatch in 1-18 days depending
upon conditions. The larvae migrate over the
foodstuff, covering it with silk as they move.
Their colour depends upon the type of food:
they are generally dirty-white but may be
tinged pinkish-brown or green. After 4-7
moults the larvae are full grown and have
attained a length of 12mm.
In this species food and environmental
conditions have a dramatic influence on the
larval phase, so that development may take
13-288 days. When mature the larvae leave
the foodstuff and spin thick white cocoons,
in which the 7mm long pupae develop. After
a pupation period of 12-43 days, the adults
emerge. These moths may overwinter as
larvae which diapause in a silken cocoon.
Rice Moth
Up to 160 eggs are laid in or near the larval
food. The larvae are dull white in colour
with brown heads, and have long, fine hairs
covering the body. They persist for 15-20
days under favourable conditions. Rice moth
larvae produce large amounts of strong
webbing and frass, before spinning a dense
white cocoon in which to pupate. The pupal
stage lasts 7-10 days.
Brown House Moth/
White-Shouldered House Moth
These species have similar life-cycles and
mixed infestations frequently occur. The
Brown house moth lays up to 650 eggs,
preferring rough open surfaces, whilst those
of the White-shouldered house moth are
sticky and laid in crevices. Brown house
moth larvae are glossy white and reach a
length of 16mm. Larvae generally diapause
for varying lengths of time, depending upon
the conditions under which they have
developed. Those of the White-shouldered
house moth are dull white and rarely exceed
14mm in length. Both species burrow into
the food, forming a silk tunnel. Pupal
cocoons are rough and incorporate foodstuff
and debris.
Common Clothes Moth
Eggs are laid amongst fibres or scattered at
random. Each female lays up to 160 eggs
during a period of 2-3 weeks. During the
summer these hatch in 4-10 days to give an
active, white translucent larva. This grows
up to 10mm in length and the head becomes
darker in colour. Feeding tunnels may be
constructed from silk and there are at least 5
moults. Larvae construct a tough cocoon in
which they moult to produce a pupa up to
7mm long. The full cycle takes between 88-
254 days, depending upon conditions.
Control
The method and timing of control measures
against moths, depends upon the species
involved. The larvae are frequently difficult
to reach because they are concealed in
foodstuffs or the fabric of buildings and may
be obvious only when they migrate.
Assessment of infestations
Adhesive traps are used for trapping stored
product moths. Attractant capsules
containing a pheromone are attached to a
sticky surface on which the moths are caught
and which is partially protected from the
environment. The trap is then suspended ca
2-3 m above the floor. They perform best in
locations which are not dusty. Alternatively
funnel traps may be used. These are usually
constructed of plastic and incorporate a
funnel system leading to a retaining chamber
in which moths are trapped and killed using
a toxicant strip, water or detergent.
They incorporate a pheromone lure and are
particularly useful in dusty locations. The
simplest traps are a dish of water containing
a little detergent. Whatever system is
employed adequate records must be kept.
a) Hygiene/management
This is important in order to avoid
conditions suitable for the development of
moth infestations. Warehouses should be
constructed so as to ensure maintenance of
correct storage conditions and allow easy
cleaning. Cracks and crevices which might
serve as harbourages should be kept to a
minimum. Stacks of commodities should be
neatly arranged above the floor on pallets,
with a gap between stacks to allow for
ventilation, regular inspection, cleaning and
treatment with insecticides if necessary.
Good packaging is particularly important to
prevent entry of larvae.
Spillages should be removed promptly, and
infested goods dealt with immediately either
by fumigation or destruction.
Uncontaminated products should not be
stored in the vicinity of infested materials.
In the case of the house and clothes moths,
fabrics should be regularly inspected and
cleaned, and alternative breeding sites, for
example birds' nests, removed if possible. It
should be remembered that soiled fabrics
make a more acceptable diet to these insects
than clean ones.
b) Insecticidal control
In order to obtain the best results,
insecticidal control measures should be
integrated with good hygiene.

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