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Mosquitos
Depending on the species mosquitos can grow to 4 to 6 mm long. Only the females bite and suck blood, which they need to produce the eggs. The males do not bite.
Usually the mosquito larvae grow in stagnant (dirty) and shallow water. Moisture and heat speed up the developing cycle of the larvae.
Mosquitos are mostly active in the time between dusk and dawn - on warm humid days in the afternoon as well. In the daytime they usually hide in moist shady places such as hedges and woodland, or in houses. They are responsible for transmitting the commonest infectious diseases throughout the world.
Tropical and sub-tropical mosquito species such as Aedes, Anopheles and Culex are carriers of dangerous diseases such as yellow or dengue fever (Aedes), malaria, virus encephalitis, filariasis (Anopheles), meningitis and filaria (threadworm) diseases (Culex).
Preventive measures and control
. Avoid stagnant water in and around your house
. Use a mosquito net during the night, and mosquito or fly gauze in windows and doors
. Use insecticides (Flying Insect Spray, Insect Strip, electric vaporiser, mosquito coils)
. Use mosquito repellents on your skin
. What helps after the bite? - Autan After-Insect-Bites
Cockroaches
Cockroaches, which hide in small cracks or crevices during the daytime, can reach lengths of 18 to 60 mm depending on species. They feed omnivorously on various organic substances, including tissue, leather and paper.
The German cockroach (Blatella germanica) is very common, and usually encountered in houses. It is relatively small and has a short life cycle of three to eight months, depending on temperature.
The German cockroach females carry their packages of about thirty eggs with them for about three weeks, and then lay the eggs randomly shortly before hatching. The larvae shed their skins several times, and gradually resemble adult cockroaches more and more closely, only they are smaller and have no wings.
Cockroaches can be carriers of a high number of bacterial and viral diseases such as diarrhoea, leprosy, catarrhal colitis, infectious hepatitis, anthrax, salmonellosis, tuberculosis and fungus diseases (aspergillus flarus).
The cockroach's excrement, skin and vomit are responsible for allergies. House dust mites and cockroaches are the commonest cause of insect allergies. In the USA 10 % to 12 % of the population reacts allergically to cockroaches.
Cockroaches like e.g. the Oriental Cockroach (Blatta orientalis) and American Cockroach (Periplaneta americana) occur throughout the world, especially in tropical regions where the environment is humid and warm. However they are also imported into Europe throughout the year, and are found in bakeries, factories, households, commercial kitchens etc.
Preventive measures and control
• Avoid accumulating rubbish and rotting substances
• Do not leave food or meals uncovered
• Keep kitchens and cooking utensils clean
• Use insecticides (sticky traps, Bait Station, Crawling Insect Spray)
Flies
Flies feed on various organic substances including excrement, and sweet and other foods.
They can reach a length of 7 to 14 mm, and reproduce in dry areas, with breeding promoted by warm temperatures.
Flies lay up to 2,000 eggs, mostly in manure, faeces, compost heaps and rubbish tips (the Musca domestica species), but also on protein-rich substances such as meat (the Calliphora vicina species). The eggs develop into white maggots, which can grow up to 12 mm long.
Their movement between bad meat, excrement and foods is not only unappetising, it also makes flies the transmitters of germs and a source of food contamination.
As a result they can transfer pathogens for infectious diseases such as cholera, dysentry, typhoid fever, salmonellosis, hepatitis and poliomyelitis.
Flies which do not bite are:
. the common housefly (Musca domestica)
. the bluebottle (Calliphora vicina)
. the meat fly (Sarcophaga carnaria)
. the blowfly (Lucilia sericata)
. the fruit fly (Drosophila melanogaster)
Flies which bite are:
. the tsetse fly, the carrier of sleeping sickness (trypanosomiasis) - only in tropical Africa
. the stable fly (Stomoxys calcitrans)
. the horsefly (Tabanidae)
Preventive measures and control
. Avoid accumulating rubbish and rotting substances
. Do not leave food or meals uncovered
. Keep kitchens and cooking utensils clean
. Use insecticides (Fly Trap, Insect Strip, Flying Insect Spray)
. Insect repellents provide effective protection against biting flies (e. g. horseflies)
Ants
Depending on the species, thousands of ants can live with one or several queens in colonies. More than 6000 ant species are known. From a human viewpoint the queen is no more than a machine for laying eggs. She has an entourage of special workers and soldiers, who look after the larvae and protect the colony.
Common ant species in Germany are the meadow or lawn ant (Teramorium caespitum) and the black garden ant (Lasius niger).
They feed on protein-rich and sugar-containing substances.
While the meadow ant workers can grow to 2 to 3.5 mm in length, the black garden ant workers are slightly bigger at 4 mm.
The meadow and black garden ants cause damage to patios or terraces and in the garden (for instance by undermining paving and damaging plants).
The pharaoh ant (Monomorium pharaonis) is found very often in tropical countries - and in Europe too. They live in the walls of houses and find their way into the house through small cracks and joints. Since they like warmth, colonies only occur in warm places (e.g. next to water pipes in the wall).
The pharaoh ant workers grow up to 2 to 2.5 mm in length. They eat both sweet and protein-rich foods and organic waste as well. In hospitals particularly there is the danger of the pharaoh ants spreading germs of all kinds, since they also have an appetite for used bandages. They are also a hazard in commercial kitchens, bakeries and indoor swimming pools.
Preventive measures and controls
. Seal up all cracks and holes in walls
. Get rid of the targets of the ant routes (for example food and waste)
. Pour boiling water over the nests
. Use insecticides (Ant Bait Station, Ant Powder, Crawling Insect Spray)
Ticks
Ticks are a problem as carriers of diseases throughout the world. They do not belong the insect species but are arachnids. In our latitudes there are about two dozen species, of which eight are of medical importance. Primarily the common castor-bean tick (Ixodes ricinus) is responsible for transmitting diseases to humans.
During each stage of their development ticks have to consume blood. To find a donor they settle on grass, fern or the underside of other leaves and bushes, and often wait for several months. If they detect a host, they drop on to it and find a suitable place to suck blood. On humans they prefer moist and warm areas such as the armpits or genital area. Their barbed proboscis unfolds after biting like an umbrella, to anchor the tick to the skin. If undisturbed feeding can continue for up to nine days. When full of blood the tick is several times larger.
The bite itself is usually unnoticeable, since pain-killing secretions are released. Often the site of the bite is only slightly red. Germs can be transmitted by the tick's saliva, and frequently also by its excrement.
Ticks are carriers of tick borne encephalitis (a viral disease), which only occurs endemically in certain areas, and of the about 100 times more common borreliosis (a bacterial disease) in all regions with temperate climates. If a circular rash appears round the tick bite and keeps increasing in size, it is imperative to consult a doctor.
Preventive measures and control
. Covering clothing will protect from tick bites.
. Apply suitable repellents to uncovered areas of the body (lotion, spray, pump spray, stick).
. The danger is less on pathways than when you go through undergrowth.
. After you have been in open countryside, examine your body for ticks.
. To remove a tick proceed as follows:
. grip the tick just above your skin
. do not twist or squash it
. do not put oil or alcohol on the tick
. pull it out straight upwards
. Prophylaxis is available through the so-called tick vaccination. However this only protects you against the more rare tick borne encephalitis, not against the much more common borreliosis! Even vaccinated persons must avoid tick bites, to avoid catching borreliosis!
Moths
The clothes moth (Tineola bisselliella) is one of the most feared material pests. Its yellow-white larvae cause the actual damage to fabrics, furs and carpets. Above all clothing which has not been worn for some time is affected.
The clothes moth grows to about 4 to 9 mm long, and can easily be recognised from its shiny golden yellow front wings.
Another type of pest, the storage pest, are the food moths, e.g. the Indian meal moth (Plodia interpunctella), which attacks stocks of food. Their larvae eat round holes in grains of wheat, rice and maize. The larvae of the lead-grey flour moth (Ephestria kuehniella) also feed on flour products. Besides this they soil and spin webs on large quantities of food. A single female flour moth can lay 200 eggs up to four times per year.
The infested food is covered in cobwebs, tastes bitter, and may harm the health of humans and animals.
Preventive measures and control
Clothes moths
. Never leave clothing damp and/or uncleaned for a lengthy period in a cupboard.
. Regularly vacuum-clean, brush or beat clothes.
. Regularly vacuum-clean infested wardrobes and bed box frames, and as a preventive measure vacuum-clean thoroughly at least twice a year.
. Lavender, cedar wood and ethereal oils are only of limited help. They may repel some of the moths, but they have no affect on the greedy larvae.
. Use insecticides (Moth Paper, Moth Bag)
Food moths
. Never store flour, grain, dough and pastry in damp conditions
. Thoroughly vacuum-clean infested cupboards, including the shelves, and remove any lining paper
. Keep food which still looks edible in a deep freezer for three days
The basic rule is:
. Contaminated foodstuffs, which are usually inedible for hygienic reasons, often have to be thrown away completely.
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