Stored Product Insects
Appearance
Approximately 3 - 4mm in length, the adult confused flour beetles are a red-brown in colour and typically distinguished by antennas which broaden gradually at the tip. These insects possess the ability to fly but rarely do so. Their larvae are whitish to yellow-brown in colour and between 1 - 5mm in length.
Life Cycle
Surviving approximately 20 days at 35°C and 45 days at 25°C, adults may live for up to 6 months in favourable conditions.
Feeding Habits
Confused flour beetles have a preference for clean flour, feeding on and pupating in flour and cereal products.
Appearance
The red rust flour beetle has close set eyes, and the last three segments of their antennae form a club. Adults grow to approximately 3 - 4mm in length and they fly in warm climates.
Life Cycle
Surviving approximately 20 days at 32.5°C and 45 days at 27.5°C, adults may live for up to 6 months in favourable conditions.
Feeding Habits
Feeds on cereals, nuts, spices and dried fruit.
Appearance
Characterised by 6 saw-like projections on each side of the thorax. The saw toothed grain beetle has a long length of head behind the eyes. Adults grow to approximately 2.5 - 3mm in length and their larvae are yellow to brown in colour, with a brown head.
Life Cycle
Surviving approximately 20 days at 35°C and 3 - 4 months at 20°C, the saw tooth grained beetle is comparatively more tolerant to temperature extremes than other pest beetles.
Feeding Habits
Feeds on cereal and cereal products, dried fruit, nuts etc.
Appearance
The biscuit beetle has a humped thorax and a body covered in fine hairs. Their wing cases have ridges with indentations. Adults grow to an approximate 2 - 3mm in length and larvae are known to be active in the early stages of development.
Life Cycle
Surviving approximately 70 days at 28°C and 200 days at 17°C, adults may live between 13 - 65 days in favourable conditions.
Feeding Habits
Biscuit beetles possess the ability to bore into hard substances and are able to detoxify some poisonous substances. Adults do not feed.
Larder beetles are occasional pests of households where they feed on a wide variety of animal protein-based products. Common foods for these beetles include leather goods, hides, skins, dried fish, pet food, bacon, cheese and feathers.
The most common species are the hide and larder beetles and they are known scientifically as Dermestes maculatus and Dermestes lardarius. Both belong to the insect family called Dermestidae and are related to carpet beetles.
Life Cycle
Females require a continuous supply of water and food to achieve their maximum egg laying capacities. Female hide beetles provided with dried meat and water lay an average of 300 eggs. Eggs are laid one at a time or in small batches on the food source, and hatch within 4 to 6 days.
Control
Infestations are controlled by locating and destroying the source of the infestation and then keeping the area clean.
Appearance
Black with a whitish band across the fore-part of the wing case, larder beetles are brown in colour and hairy. Larvae are distinguished by their comet shape, and these quick moving insects are known to migrate to pupate in solid material.
Life Cycle
Dermestes beetles have a lifespan of approximately 2 - 3 months at 18 - 25°C.
Feeding Habits
Dermestes beetles feed on a wide variety of animal protein based products and are serious pests in silkworm production and in museums. Common food sources include leather goods, hides, skins, dried fish, pet food, bacon, cheese and feathers. Household infestations are sometimes attributed to the presence of bird or rodent carcasses, old bird nests, or accumulations of dead insects. Dermestes may occasionally feed on plant material of high protein content, but this is not a preferred food source. Mature Dermestes larvae also bore into hard substances such as wood, cork, tobacco & plaster.
Appearance
The size of booklice varies according to species, typically 1 - 2 mm long, they range from a pale yellow-brown to dark brown in colour. Nymphs are very small and often appear transparent.
Life Cycle
Booklice prefer high temperatures of 25 - 30°C but some species are known to breed at lower temperatures of 5 - 15°C.
Feeding Habits
Commonly found in homes and on pallets in factories.
Appearance
With oval indentations in the thorax, grain weevils are legless and a black-brown in colour. Adults grow up to an approximate 2 - 3mm in length.
Life Cycle
Grain weevils live for approximately 30 days at 30°C. They can live for up to 8 - 16 weeks in favourable conditions.
Feeding Habits
Feeds on grain, wheat, rye, cereal. Grain weevil larvae are usually hidden where they pupate, therefore newly emerged adults leave an identifiable emergence hole in the grain.
Appearance
Cigarette beetles have a humped thorax, smooth wing cases and adults grow to an approximate 2 - 3mm in length.
Life Cycle
Living for approximately 25 days at 30 - 35°C, cigarette beetles can live for 2 - 6 weeks in favourable conditions.
Feeding Habits
The Cigarette beetle is able to fly. It feeds on a wide range of stored products including tobacco, cereal, pulses, dried fruit and spices.
Appearance
With round indentations on the thorax and reddish spots on their wing cases, the legless rice weevil can grow up to an approximate 2 - 3mm in length.
Life Cycle
Surviving approximately 100 days at 18°C, rice weevils can live for several months to a year in favourable conditions. Larvae will not develop below 16°C.
Feeding Habits
Feeds on grain and seeds. Rice weevil larvae are usually hidden where they pupate, therefore newly emerged adults leave an identifiable emergence hole in the grain.
Appearance
With 6 saw-like projections on each side of the thorax and a short length of head behind the eyes, merchant grain beetles grow up to approximately 2.5 to 3mm in length. Their larvae are yellow to brown in colour, with a black head.
Life Cycle
Merchant grain beetles cannot tolerate low temperatures. They thrive in temperatures of 30 - 33°C.
Feeding Habits
Particularly fond of dried fruit and chocolate.
Appearance
With a flattened, light red to dark reddish brown body, the flat grain beetle is characterised by a very long antennae. Adults are an approximate 2.5mm in length, they have wings but rarely fly. Larvae are a yellow-white in colour, developing from 0.5mm to 4mm when mature.
Life Cycle
The flat grain beetle prefers warm, damp conditions, with a lifespan of 60 to 100 days at 21°C and 25 days at 38°C.
Feeding Habits
Feeds on cereal, dates, dried fruit and other produce.
Appearance
Male broadhorned beetles have two enlarged mandibles on the head, giving the appearance of horns hence the name. Females are very similar In appearance to the confused flour beetle.
They are approximately 3.5 to 4.5 mm in length
Life Cycle
Broadhorned flour beetles cannot complete their life cycle below 10°C. Their accepted temperature limits are 15 to 32°C.
Feeding Habits
Feeds on dough, semolina & flour etc but they may supplement their diet with moth eggs and larvae.
Appearance
Approximately 20mm long, yellow mealworm beetles are shiny, dark-brown or black. Larvae are a honey-yellow color with hard, highly polished worm-like body.
Life Cycle
They are highly resistant to cold temperatures.
Females lay about 275 - 600 white, bean-shaped eggs singly or in clusters during spring, which hatch into larvae in 4 to 14 days.
The pupal stage lasts 7 - 24 days, first white and then turning yellow (not enclosed in a cocoon) and finally emerging as adults with a lifespan of 2 to 3 months.
Feeding Habits
Adult yellow mealworm beetles are attracted to night-lights, they are strong fliers and are commonly found in dark areas.
Appearance
Covered in brown and golden hairs, the Australian spider beetle has a spider-like appearance and adults grow to approximately 2.4mm to 4mm in length.
Life Cycle
Australian spider beetles live for up to 4 months at optimum temperatures of 20 to 25°C.
Feeding Habits
Larvae are often found feeding on miscellaneous debris, this spider beetle is able to bore into various inedible materials prior to pupation. Active in dark, damp places and often associated with bird nests.
Appearance
Covered in golden-yellow hairs, the Golden spider beetle has an ovoid abdomen with a pinched waist. Adults grow to approximately 2mm to 4.5mm in length.
Life Cycle
Surviving up 6 - 7 months at 20°C, the Golden spider beetle can live up to 9 months in favourable conditions.
Feeding Habits
Commonly linked to the damage of textiles in the domestic home, adults appear in greater numbers from June to July and October to November.
Appearance
White or pale brown in colour, the slow moving flour mite can grow up to 0.5mm long. Larvae are white in colour and pass through two 8-legged nymphal stages.
Life Cycle
Flour mites have a lifespan of 9 to 11 days at 23°C and 90% relative humidity.
Feeding Habits
Under adverse conditions, flour mites may pass through a long, resting stage called a hypopus.
Appearance
Cheese mites have soft, hairy cream white bodies with 8 hairless legs. Adults grow up to an approximate 0.5mm in length.
Life Cycle
The cheese mite favours warm, moist conditions. Eggs mature in 10 days at room temperature. Females can lay up to 900 eggs in a lifetime at a rate of 20 to 30 a day. Adults can live for up to 70 days.
Feeding Habits
They prefer old cheese to young cheese but will also feed on nuts, dried eggs, fruit, flour and tobacco. Cheese mites are capable of contaminating foods which can then cause skin or gut irritation.
Appearance
An approximate 7 - 9mm in length, the wingspan of an Indian meal moth develops to 15 - 20mm; the first third of forewings are a pale buff colour and the remainder of the winds are a reddish-brown. Larvae are a yellowish-white, reddish or greenish (depending on diet) with a brown head.
Life Cycle
Surviving for 35 days at 35°C, the Indian meal moth lives for much longer at lower temperatures or when feeding on low nutrition foods.
Feeding Habits
Feeds on nuts, dried fruit and grain (maize)
Appearance
Characterised by a black zig zag pattern across grey wings, the mill moth is an approximate 7 - 9mm in length with a wing span of 15 - 20mm. Larvae lives within a silken tube and have a pinkish or greenish tinge (depending on diet) with a brown head.
Life Cycle
Surviving for 153 days at 17 and 42 days at 30°C, the prolific silk spinners can live for up to 2 weeks in favourable conditions.
Feeding Habits
A pest particular to flour, rarely feeds on other products.
Appearance
Grey-brown banded with lighter and darker colours, tropical warehouse moths are approximately 7 - 9mm in length with a wingspan of 15 - 20mm. Larvae are whitish, yellowish or reddish in colour (depending on diet) and tend to migrate to dark areas to pupate.
Life Cycle
Tropical warehouse moths have a lifespan of 31 days at an optimum temperature of 32°C.
Feeding Habits
Often associated with imported food cargoes, the tropical warehouse moth is primarily a pest of stored cereal, nuts, dried fruit, oil seeds and oil cakes. Rarely feeds on tobacco and animal products. Adults do not feed.
Appearance
An approximate 7 - 9mm in length with a wing span of 10 - 16mm, the warehouse moth is grey-brown banded with lighter and darker colours. Larvae are whitish, yellowish or reddish in colour (depending on diet) and tend to migrate to dark areas to pupate.
Life Cycle
Eggs hatch from 3 -6 days above 20°C and pupae matures from 10 - 20 days over a temperature range of 18 - 26°C.
Feeding Habits
A formidable pest of cocoa beans, chocolate confectionary, dried fruit and nuts.
Many of these insect species are so small that you may not notice a problem at first, but always look out for the following signs of stored product insects:
- Damage to raw materials and foodstuffs.
- Emerging adult weevils leave visible exit holes in grains.
- Infected grain is liable to become warmer which can lead to damp, mould and even grain germination.
- Insect tracks through floury dust created as adults move from one food source to the next.
- Webbing produced by the larvae of Warehouse and Mill moths as they feed and spread.
- Flour and grain beetles can cause discoloration of commodities and make them prone to moulding.
- These pests can also taint goods with their waste materials.
Once in your home, stored product insects are highly mobile and will spread quickly through your property in search of other foods such as dried fruit, rice and cereals.
Act quickly as the longer you leave it the more difficult it will be to find all the sources of the infestation.
You must remove the source materials of the infestation as well as cleaning up any spillages that might occur.
Store all food products including dry pet food in strong, tightly sealed containers so that insects can't get to them.
Most stored product insects will be found in infected foodstuffs in kitchens, larders or store rooms close to a food source.
The most common insects to infest food products in homes are flour beetles, the saw toothed grain beetle and the Indian meal moth.
Flour beetles will breed in milled grain such as flour, rice, oats and cereals. They leave a mouldy taint to any products they infest.
Saw toothed grain beetles will eat cereals, dried fruits, macaroni and crackers.
Indian meal moth larvae will eat the same cereals, dried fruits and nuts as other stored product pests, but will also infest dried herbs, spices, dry dog food, fish food, cake mixes and bird seed.
Stored product insects can chew through packaging to access the food inside to eat or lay eggs.
Any business that handles cereals, grains or dried food products is at risk from stored product insects. There are many different species of insect - mainly beetles and moths - that can damage raw food materials and contaminate finished products, making them unfit for consumption.
Not sure if you have an SPI problem? Find all the signs to look out for here.
We Use a Range of Pest Management Solutions to Treat SPIs:
- Fumigation options
- Highly targeted insecticide sprays
- Chemical-free heat treatment
With years of experience covering many different industries, we are able to offer highly tailored solutions. Specific information for food manufacturing and processing facilities can be found on our food processing pest management page
- Risk of Insects in Stored Foods
- Serious loss of valuable stock, foodstuffs and commodities
- Potential damage to your brand, reputation, custom and income
- Non-compliance with legislation could lead to fines or prosecution
Textile Pest Species
Textile pests are scavengers of natural fibres such as wools, silks, feathers, animal hair and fur. Damage is done by the larval stage of the beetle, while adults feed on flowers and shrubs.
Spiders
There are more than 35,000 species of spiders worldwide but less than a 1,000 of these are found in the UK. Although they are seen as beneficial to our environment, many people do have an inherent fear of spiders, known as Arachnophobia. This causes feelings of uneasiness at the mere sight of spiders, leading to excessive sweating, crying and panic attacks.
The majority of species of spiders found in the UK are not considered dangerous and they rarely bite. If you do get a spider bite, it often has little effect on most people, while a few species can cause an exceptional reaction due to their venom.
The majority of the spiders in this country produce webs and this is a key way to identify if spiders are present in your home or business.
In general, spiders can be found in dark, secluded areas, both in your home and garden.
Look for spider webs Tthe size and shape of spider webs vary by species. Some are orb-shaped while others are funnel-shaped.
Some spider species live in burrows rather than webs, while others are free ranging and take refuge in crevices.
Some species of spiders are attracted to moist environments so check your basements, walls, sheds and other damp locations.
Other species can be found in places such as attics, the junction of a wall and ceiling, cupboards and storage boxes.
Spiders feed on other insects and prey on ants, flies, woodlice and other spiders, so where there is a plentiful supply of other insects, spiders will wait to find their next meal.
As the temperature drops in Autumn, spiders become more active, looking for a mate they come out of their hiding places. Towards the end of Autumn many die off, but some hibernate until the following Spring.
Spider eggs are laid into a silken sac, on average about 100 eggs in each sac, which may be fixed to a surface, hidden in the web or carried by the female. Signs of the sacs fixed indoors indicate that soon there will be more spiders around.
Spiders rarely bite in the UK and none of the indigenous UK spiders are considered dangerous. Most spider bites will have little effect on people but some species can cause a reaction due to the venom injected.
Facts about the bites of a False Widow, Yellow Sack and a Brown Recluse spider.
Adult False Widow spiders are not naturally aggressive towards people. They only bite as a defensive measure if they feel threatened. Most defensive bites to people occur when the spider is unintentionally squeezed or pinched. Bites may result in localised pain, tingling and small swelling around the bite.
Occasionally more serious symptoms can occur but these are an exceptional reaction of the individual to the spider's venom.
Appearance
Brown bulbous abdomen with pale markings - females grow to 15mm.
Habits
Hangs upside down from 'tangle webs' in dark corners.
Closely resembles the black widow spider.
The web is typically a random scaffolding of threads.
Natural habits include low vegetation and undisturbed areas.
In urban environments they occur in unused sheds, outbuildings and indoors.
Bites are fairly rare and only occur when the spider is feeling threatened. Generally this will produce localised short-term pain and swelling.
Their bite is sharp and painful and will cause erythema (red marking of the skin like a rash) and swelling. A wheal may develop, producing a necrotic area, which can take eight weeks to heal. Pain or numbness at the site of the bite, may be followed by sweating and nausea lasting for up to 24 hours.
Adult Yellow Sac spiders can be seen from April through November. They emerge at night to look for food. They drop to the floor to seek cover when disturbed.
They are likely to enter homes during early Autumn when their outdoor food supply decreases.
Appearance
Pale in colour, abdomen can be yellow or beige with a faint dark stripe running lengthwise.
6mm to 9.5 mm long.
4 pairs of legs, the 1st pair longer than the 4th.
Eight similarly sized dark eyes arranged in two horizontal rows.
Life Cycle
A female produces around 5 egg sacs each with 30 to 48 eggs. The female may produce several egg masses during her lifetime.
Eggs are laid in autumn.
Young spiders emerge the following spring.
Approximately 30% of the adult males get eaten by females after mating.
Habits
Feeding is usually on small insects.
Location - They build a silken tube or sac (instead of a web) in a protected area, which is used as their daytime retreat.
Externally this can be within a leaf or under logs; Indoors this can be or at the junction of a wall and ceiling or behind pictures and shelves. They are normally outdoor spiders, but will set-up indoors if there are small insects available and are found on walls and in corners close to the ceiling, they drop from ceilings on silk threads.
They only bite when crushed, handled or disturbed. Both sexes are venomous. Reactions to bites will vary - some people are unaffected, some may feel a pinprick whilst others may feel a stinging sensation followed by intense pain.
Some people may not be aware of the bite for 2 to 8 hours.
Brown Recluse spiders are often called 'fiddleback' or 'violin' spiders because of the violin-shaped marking on the top surface which points from the head area toward the abdomen.
Appearance
6 mm to 19mm long.
Brown or deep yellow colour.
Long, thin, brown legs covered with fine hairs.
Six eyes that are arranged in pairs in a semicircle.
Life Cycle
Eggs are laid primarily from May to July.
The female lays about 50 eggs in an off-white silky sac approx. 2/3 inch diameter.
Young spiders emerge around 1 month later.
It takes on average one year to reach the adult stage.
Adults can live 1-2 years.
Habits
Locations - They prefer secluded, dark, undisturbed sites indoors or outdoors. Indoors, they may be found in attics, basements, cuilt in cupboards, and ductwork, in storage boxes, shoes or behind furniture. Externally they may be found in barns, storage sheds, garages and under logs, loose stones and stacks of lumber.
Feeding - They prefer dead insects.
They can survive about 6 months without food or water.
Visibility - The sac serves as the spider's daytime retreat. They tend to look for food at night.
Other Common Spider Species
There are thousands of species of spiders around the world, but here in the UK only a few are considered as common pests:
Wolf spiders hunt at night but spend the day hidden amongst moss and decaying matter.
Appearance
Adult female approximately 8 mm in length, males approximately 6 mm in length. They are generally brown to grey in colour.
Life Cycle
Wolf spider mothers carry their egg sacs around with them attached to spinnerets under the abdomen.
When the young spiders hatch, they climb onto their mother's back where they live for the first few weeks of life.
Habits
They live in a shallow burrow, with an open and unadorned entrance.
Harvestman spiders can be found in fields and forests.
Appearance
Adults are from 3.5 to 9mm in length. The upper body surface has light grey/brown pattern whilst the lower surface is typically cream.
Life Cycle
The females lay eggs in moist soil.
The eggs survive through winter and hatch in the spring.
Only one batch of eggs is laid each year.
Habits
They climb tree trunks or look for food on the ground.
They feed on many soft bodied arthropods, including aphids, caterpillars, beetle larvae, and small slugs.
Common House spiders can be found in your home or business.
Appearance
Adult body length excluding legs is 6 to 10mm. It has a yellow/brown body with faint markings. The abdomen is pale-grey-brown with short hairs.
Life Cycle
The egg sac produced by the female is spherical, covered with a layer of silk and placed within the web structure.
The male will mate several times with the female before dying.
Adults may live for several years.
Habits
Found in buildings, sheds and walls.
This spider produces a sheet web.
The cellar spider is sometimes known as the daddy longlegs spider. It gets its name due to being primarily found on ceilings of rooms or cellars.
Appearance
Adults are 2.5cm, four long pairs of legs and two body parts.
Very long, thin legs.
Will rapidly shake its body on the web when disturbed.
Habits
Diet primarily consists of insects which they catch and eat.
Breed at any time of the year not being affected by seasons.
Spiders are most likely to enter your home in the autumn in search of a warm place to spend the winter.
The best advice, in general, is to leave them alone. This can be difficult for the many people who have a real fear of spiders.
The majority of spider infestations are more of an annoyance - particularly their webs. However, on occasions, more serious situations can occur. One example of this is the False Widow spider (the common name for a group of species in the genus Steatoda), where there is potential for harm from their bites.
To control a small infestation, you could use DIY spider products however an established infestation may require professional treatment to ensure that it does not reoccur.
The most effective way to control spiders is to limit their food source. This includes clearing away dead flies, beetles and other crawling insects.
Vacuum regularly, both high and low and in particular sheltered spots such as the backs of cupboards, underneath work surfaces or under/behind large furniture.
Remove webs on a regular basis.
Fill in gaps - in walls, around pipework and under doors.
Remove sheltering sites such as firewood piles, garden bags, compost heaps and general clutter around the garden and near your property.
Deter all insects by using lighting in a way that deters other insects including flies and moths that spiders feed on.
Silverfish
More than just a nuisance in homes, Silverfish are known for their destructive feeding habits and can cause a serious problem in large numbers, causing damage to books, photographs, paintings, plaster and other household items containing starch or cellulose.
Silverfish survive in most environments, but thrive in conditions of high humidity and can often be found in dark, damp areas such as kitchens, bathrooms, basements and attics.
Appearance
Silvery-blue or grey in colour.
They have a tapered, tail like appearance.
They are wingless and have 2 slender antennae.
These teardrop-shaped insects measure up to 10mm to 12 mm in length.
Life Cycle
Silverfish reproduction habits vary by species - some species laying a few eggs a day and others laying clusters of 2 to 20 eggs on a daily basis.
Habits
Silverfish eggs are commonly hidden in tiny cracks or crevices, making them extremely difficult to locate.
They prefer warm, humid places such as bathrooms and kitchens and are especially attracted to paper and damp clothing.
They feed on carbohydrates, especially sugars and starches.
Silverfish are serpentine insects that require damp and humid conditions and thrive in kitchens, laundry rooms, bathrooms and other dark, isolated areas. Fixing leaks in pipework, improving ventilation and using dehumidifiers can help discourage silverfish.
Silverfish feed on: Starch, Cellulose and Sugar
They can be found in a variety of common items in households and businesses such as books, wallpaper, paintings, fabrics, carpets, coffee, sugar, pasta and other food debris.
Remove food sources by keeping dust and debris to a minimum and vacuum rarely disturbed areas. In the home, store food in containers with tightly sealed lids.
You can use DIY sprays to tackle isolated incidences of silver fish but large infestations will require the services of a professional pest control company like Peskill.