Ants belong to the group of insects that includes bees, wasps, sawflies and wood wasps. In Australia, about 3000 species of ants are known. Ants are social insects that live in more or less permanent nests. Colony sizes vary enormously and are mostly located in soil, wood and among rocks. In relation to their feeding habits, ants may be predators, perhaps with specific prey, or scavengers, which again may have a specific diet.
Being very common intruders in and around buildings, ants tend to be very familiar insects. They are commonly observed around foundations and in walls, roof voids, kitchens, lawns and gardens, the wood of decaying trees, and rockeries. As a group, ants are considered by many to be among the most successful of all insects. Typically, worker ants forage from the nest for food. Many do this by travelling in fairly well-defined trails, once a food source has been established. Methods employed in trail marking may include reference to landmarks, orientation with respect to light and, very commonly, the laying down of ‘scent trails’ in the form of trail-marking pheromone secretions. More generally, orientation and communication in ants may rely on smell, taste, hearing, touch or sight.
As well as generally ‘nuisance’ aspects, ants may present a health risk. There are known instances of ants mechanically carrying, on their bodies or in their digestive tract, disease organisms causing dysentery, smallpox and a variety of pathogenic bacteria, including Salmonella. In addition to the health threat posed and nuisance aspects, some ants may bite or sting humans.
Effective control of ants often relies on a knowledge of their foraging and nesting habits. Direct treatment of the nest, where possible, can provide the most effective, longer-term control. Alternatively, the use of chemical barriers that interfere between the nest and possible food sources is often effective.
Adults are generally medium to large in size, flattened and when viewed from above, mostly oval shaped, with the head shielded beneath the head. They have long and slender thread-like antennae, legs well suited to running, well developed compound eyes and chewing mouthparts. Cockroaches eat stored foods and other materials. They contaminate foods and food handling areas with droppings, cast skins, regurgitation marks and odours caused by abdominal secretions. Infestations of cockroaches are generally regarded as a threat to human health. Some people are allergic to cockroaches. extracts of cockroaches can bring about positive skin reactions in sensitive people, and may cause an asthma attach in asthmatics.
Fleas are small, very specialised parasitic insects. There are roughly 90 species known in Australia. Adult fleas are blood suckers, the majority feeding on mammals (eg. Dogs, cats, pigs) and some feeding on birds. Some flea species are very widespread and as a result of their biting habit, which may cause severe irritation, and their role in disease transmission, the group has justly earned a reputation of being extremely important in the medical and public health context.
Fleas prefer warm, humid conditions and hence are often a pest during summer. When climatic conditions are favourable, the development of larvae outdoors can be very widespread. More importantly, some fleas are carriers of serious diseases, such as bubonic plague, murine typhus and a number of tapeworm infections. Effective flea control often relies on the well-directed application of chemical insecticides and / or insect growth regulators, backed up by procedures that the individual undertakes to help make the environment less suitable for the development of fleas.
An important consideration regarding flies is the threat that flies pose to public health. The structure and habits of many flies are such that they can efficiently transmit diseases to humans. They have hairy bodies that can carry disease organisms, and sponging mouthparts that often involve vomiting in the eating process. They are very mobile and freely interchange between decaying excrement or wastes and human foods and utensils. Studies have shown correlations between a high incidence of enteric disease and the presence of a large fly population. The list of disease-causing organisms that flies may harbour on or in their bodies is enormous.
The control or exclusion of flies may employ non-chemical or chemical control procedures, or often a combination of both. In such an integrated approach, the use of insecticides must be judicious and efficient. The more prevalent pest species of fly breed very rapidly, and resistance to certain types of insecticides often develops.
Millipedes generally feed on organic matter, usually vegetable. They do not inflict a wound, but produce a fluid that stains and has repellent effect on other arachnids and insects.
Mosquitoes pose a significant threat to the health and comfort of humans and livestock. The term biting is widely applied to the piercing and sucking feeding action of adult female mosquitoes. This habit can be so annoying and irritating that it can reduce livestock yield. Humans, too, can suffer mild to severe irritation. Host-finding probably relies largely on the detection of warmth, moisture and carbon dioxide in the atmosphere.
The importance of the role that mosquitoes play in the transmission of diseases cannot be overstated. Millions of human lives have been lost to disease distributed and transmitted by mosquitoes. The more dangerous diseases transmitted by mosquitoes rely on biological transmission.
In Australia, mosquitoes have been responsible for the transmission of a range of diseases in humans: Malaria, Dengue, Ross River virus, Barmah Forest virus, Murray Valley encephalitis virus, Kunjin Virus, and Japanese encephalitis virus!
The disruption of breeding sites can do much to reduce a mosquito problem. Individuals can prevent localised breeding by preventing water accumulations as may occur in rubbish and blocked roof guttering. The use of insecticides can also be applied in killing larvae and or repelling mosquitoes.
Rats and mice are serious pests of humans and they can, in some cases, be difficult to control.
The rodents that are of great concern in the urban pest control text, not just in Australia but in many countries, are
Norway rat, Roof rat, House mouse
These animals are well adapted to living in very close association with humans, sharing their food and shelter. Throughout history, rats and mice have been responsible for enormous losses of food and, owing to their ability to transmit diseases to humans by a variety of means, enormous losses of human life. Any serious attempt to control rodents in buildings must, of necessity, begin with a thorough inspection of the premises. Operators seldom have the opportunity to inspect premises at night when the activity may be directly observed, so signs of activity observed during the day must be interpreted to yield as much information as possible about the types of rodents present, the extent of their activity, their routes of travel and the approximate size of the population, and any other information that will aid in the determination of proper and effective control procedures.
Silverfish have flattened bodies and most species are clothed in tiny scales. In Australia, about five species of silverfish have, with varying degrees of success, exploited built environments, feeding on, and often damaging, books, paper and clothing – in particular, the starchy glues and sizing on these articles. These are agile, fast-running, scale-covered insects that are primitively wingless.
These pests restrict their activities to relatively undisturbed areas (eg. Bookcases, storage rooms), where they may damage paper, fabrics and other materials. Within buildings, silverfish may be found almost anywhere. While frequently found in roof cavities, they may also occur in wall voids, subfloor areas and many places within the dwelling parts of premises. They feed on most types of human food. Inspection is an important prerequisite to treatment. Thorough inspection should involve moving stored articles to real disturbed silverfish.
Most spiders are nocturnal, during the day they are seldom seen, unless they are sought or disturbed in their natural environments. When the light fades, spiders become active. They leave the protection of their burrows or shelters and go out in search of food or, in the case of web-spinning spiders, construct their webs to snare prey. As day breaks, most spiders seek the safety of their shelters again.
The venom of spiders is not necessarily poisonous to warm-blooded animals. Some spiders are capable of causing death by introducing an extremely toxic substance into the bloodstream of warm-blooded animals, including humans, but most spider bites result in no more than localised swelling or irritation. Rarely, a spider that inflicts a deep wound may introduce bacteria into the bloodstream, causing septicaemia.
Within the broad range of urban pest control activities, the control of ground-dwelling spiders has involved serious misuse of pesticides. This has been largely manifested in the blanket-spraying treatment, using very stable, sometimes very toxic, organochlorine insecticides. However, these insecticides are no longer approved for spider control and their use has been banned in many countries of the world.
Things to consider to prevent a bite:
- Wear gloves when gardening and handling soil or rubbish
- Wear sensible footwear when walking outside, particularly at night
- Don’t leave toys, clothes and other such articles on the ground, particularly overnight.
- Be particularly alert for wandering male funnel webs during the warmer months, (January to March). It is their mating season, and they may wander into yards and buildings in search for a mate.
- Be alert for wandering ground-dwelling spiders after long periods of very wet weather.
- Be alert for wandering ground-dwelling spiders following the widespread application of insecticides.
If you are noticing a high activity of spiders in or around your home, it is best to have a professional inspect your area.
A survey of many hundreds of houses carried out in New South Wales in 1982-1983 showed that one house in every five had active termites or had a termite history. It is therefore essential that pest controllers engaged in the control of structural pests have a good working knowledge of termites. Identification of the species is important, as many species require no action, and expensive control measures against these destroy client confidence in the pest control industry generally.
Termites are mostly small and soft-bodied, with chewing mouthparts and beadlike antennae. They are mostly pale brown to white. Termites live in colonies and the size of the colony varies from a few hundred to hundreds of thousands or even millions. Considerable damage is caused to railway sleepers, poles, posts, bridges, all kinds of buildings, forest trees and even a variety of crops in the drier inland.
The cost of termite treatment and the renewal of damaged timbers have been major factors in the general acceptance for soil pre-treatment during the erection of a building. It is now a normal provision in many building specifications for a soil-barrier treatment to be carried out.
Ticks may cause the death of warm-blooded animals by introducing toxins into the bloodstream, or cause non-fatal infections. There are many species of ticks, and their identification is usually a task for the specialist.
The following symptoms start to appear about 3-7 days after the tick has attached itself to an animal:
- Loss of appetite, lassitude and depression occur
- Discharge from the eyes may be present
- Paralysis is first evident in the hind limbs, when the animal finds difficulty in walking and coordinating its movements
- Vomiting may be evident
- Paralysis extends to the forequarters
- Death may be caused by respiratory failure brought about by paralysis of the throat region, or heart failure may occur.