Insect Pests: Beetles
Different varieties of beetles provide three problems when they enter your home:
- Pollution of foodstuff, particularly dried food such as cereals, flour, grain, rice and nuts
- Damage to natural fabrics such as wool, cotton and silk – synthetic materials such as nylon, polyester and rayon are not normally damaged by beetles
- Damage to wooden furniture and structures such as beams and joists – and even lead!
Some beetles and the larva will cause problems in two of the above areas.
Careful storage in airtight containers will protect foodstuff and the whole home can be further protected by covering airbricks with MouseMesh: the grill size (2mm) will prevent most beetles from entering. Where dry foods are stored and/or processed the use of MouseMesh to prevent beetles entering is strongly recommended.
Beetles and Foodstuff
Below are just a few of the beetles that eat, and pollute, dried foods stored in the home.
Typical weevil with a relatively long snout projecting forward from the front of the head and with distinctly elbowed antennae. Brown to almost black in colour, usually with two paler marks on each wing-case (body 2-3 mm long). Found in granaries, bakeries and other food stores where it will attack all kinds grain and cereal products (maize, rye, wheat, millet, etc.) as well as rice.
There are several species of reddish-brown beetles, all very similar in general appearance – their body is 2-4 mm long. All are fairly common pests found in stored grain, flour, bran and other cereal products.
Reddish-brown, with a distinctive large tooth on each mandible (jaw), which gives the beetle a ‘horned’ appearance. The body is 3-5 mm long. Like the flour beetles, it occurs in stored cereals and cereal products. It is also found outdoors living under the bark of old deciduous trees, particularly that of elms.
These large beetles are entirely dull black in colour, with a distinctive tail-like extension of the wing-cases. The body is 20-30 mm long. They live in dark places in and around houses and other buildings, typically in kitchens, cellars, sheds, stables and barns, but may also occur in roof spaces where birds have been nesting. The beetles feed on any spilled or waste animal and vegetable matter, including badly stored grain, bran and other cereal products. When disturbed, these beetles have the interesting habit of adopting a sort of ‘headstand’, by extending the hind-legs and pushing against the ground, so tilting the whole body with tail-end upwards. If the disturbance continues, they can squirt a smelly, yellowish-brown fluid from the raised tip of the abdomen, sometimes to a distance of several centimetres. This fluid contains quinones, which are powerful skin irritants and provide the beetles with an effective defence mechanism to repel would-be predators.
Beetles and Natural Fabrics
Usually it is not the adult beetle that causes damage to fabrics, rather it is the larva of the beetles that are the real pests.
Blackish-brown with two white spots on its back. The body is 4-6 mm long, and covered with fine hairs. The larval stages can do severe damage to skins, furs, carpets, old blankets and the like. Also found in corn mills and grain stores.
Brown or brownish-black, with relatively long legs and antennae. The body is 2-5mm long, and usually covered with fine hairs. They are found in homes and warehouses, often in large numbers. They feed and develop mainly on starchy materials such as grain and flour, but may attack all kinds of substances of both plant and animal origin. The larvae (often called woolly bears) often chew pupation-holes in wood and textiles and, likewise, may cause extensive damage to these materials. They can survive up to 10 months and will hibernate through winter.
Beetles and Wood
Again it is the larvae that do the damage – protect your home by fitting Mousemesh to prevent the adults entering through airbricks!
Sometimes known as the Larder or Bacon Beetle it is black, with a broad, wavy, yellowish-white or greyish band across the wing-cases broken by several black marks. The body is 7-10 mm long, and is covered with fine hairs. When the larvae are ready to pupate, they often chew pupation-holes in wood, cork, paper, textiles, mortar and even soft metals, especially lead, and may cause considerable damage to these materials.
The adults are 2-9 mm in length and are short lived and do not feed. Again it is the larval stage that does the damage.