Pest Control: What Are Pests and Pathogens?

Pests can damage food and building materials, transmit disease, and cause fires by chewing through electrical wires.

Regular pest control protects home and business values, preserves occupants’ health and safety, and keeps homes and businesses clean. Be sure to ask about a company’s license, insurance, and copies of the pesticide labels used. Contact Coquitlam Pest Control now!

Pests are organisms that cause undesirable effects on humans, animals, plants, or the environment. An insect pest, for example, can devastate crops such as soybeans. Insects also damage trees and shrubs by eating the leaves, which reduces their ability to capture energy from sunlight (photosynthesis). A pathogen that causes a disease in a plant is considered a plant pest. Pests, such as head lice and ringworm, may harm people by spreading diseases that affect health or well-being.

In some cases, cultural practices can control the number or the type of pest that attacks cultivated plants. These practices usually involve altering the environment or the condition of the host plant in a way that disrupts the normal relationship between the pest and the host, making it less likely for the pest to survive, grow, or reproduce. Common cultural practices include rotating crops, cultivating the soil, varying time or planting or harvesting, planting trap crops, adjusting row width, pruning, and thinning or fertilizing cultivated plants.

Some pest situations can be handled mainly by monitoring and scouting or by using mechanical or biological controls. Monitoring usually involves counting or seeing the pests, and often includes checking environmental conditions, such as temperature and moisture levels.

Biological and mechanical control methods are physical controls, such as traps, or the use of predators or parasites that kill or prevent pests. In agriculture, such methods include tilling and plowing the soil, tillage of crop fields, and the use of insects, birds, or mammals to control rodents, weeds, and other insects.

Chemical control methods use poisons to kill or prevent pests. They are often effective in controlling some types of pests, but others develop resistance. To avoid the buildup of resistant populations, new control techniques are continually being developed.

It is important to identify a pest before using any control method. This allows you to determine whether the pest is a continuous threat or a sporadic nuisance and what steps might be needed to keep it from returning. Moreover, the identification process highlights what the pest needs in order to survive and reproduce, which can help guide prevention and control efforts.

Rodents

Rodents (Ordered Rodentia) include a very wide variety of species, from the pygmy mouse and squirrel to capybaras. Their unifying feature is a pair of unremittingly growing incisors in their upper and lower jaws. Rodents are highly adaptable and can live in almost any habitat, from forests and grasslands to urban settings. They have high reproductive rates, short gestation periods, and can produce multiple litters each year.

Rodents can cause a variety of problems in our human communities, including fires caused by gnawing on electrical wires, destruction of crops and gardens, and contamination of food and water supplies. They also can transmit pathogens that can make people sick. Rodents are opportunistic feeders and will consume whatever is available. For this reason, it is important to store all foods in sealed containers and to clean up crumbs, spills, and discarded items promptly.

The most common rodent pests are mice and rats. They enter structures through gaps and cracks, openings around pipes and vents, and under and behind furniture and appliances. They are active at night and can be spotted in lit areas by their droppings, footprints, gnaw marks, rub marks (grease from rats rubbing against surfaces), and sebum marks (dark oil deposits that accumulate on paths used by rodents).

It is essential to use an integrated approach to managing rodents. This includes sanitation, exclusion, trapping, and lethal control. Traps should be placed in areas where rodents are seen, including inside and under the eaves of buildings. They should be emptied frequently and back-up traps set in case of bait or trap failure. A combination of a low-toxicity bait and traps is best for reducing populations.

Because of their ability to chew through almost anything, rodents can damage structures and equipment. They can also damage landscape and garden plants by nibbling on roots or destroying seeds and bulbs. Rodents can also contaminate food and water by chewing through plastic or metal packaging. Moreover, they can transmit diseases such as salmonella and hantavirus. In addition, they are known to contribute to global malnutrition by destroying or consuming crop yields.

Insects

Insects are one of the most diverse groups of organisms in nature with over six million described species. They are hexapod (three-part) invertebrates with a chitinous exoskeleton, a head, thorax and abdomen and three pairs of jointed legs. Insects have compound eyes and a pair of antennae, which help them detect sounds, movements and chemicals. Insect mouthparts vary from sucking to chewing, and some insects use a long proboscis to drink nectar.

Many organisms are considered pests in a particular area because they damage crops and other natural resources, and may interfere with sustainable agriculture. Often the organisms rise to pest status when they escape normal control by natural regulating agents, such as predators, parasitoids and pathogens. The organisms can then grow at a rate that exceeds that of their natural enemies, and cause significant crop loss.

Natural enemies are organisms that can naturally reduce populations of pests, making them less damaging. These are often called natural enemies, predators, and parasitoids. Examples include birds, bats and fish, and nematodes and other fungi that infect insect pests. These organisms can also be used as biocontrol agents, inundating the soil with bacteria that will kill the pests when they burrow into the plant roots.

Chemicals can be very effective against some pests, but they are toxic to other organisms as well and can persist in the environment, affecting water supply, soil productivity, air quality, and biomagnification up the food chain. The toxicity of chemical pesticides can make them a major problem in wine and other agricultural industries, and they must be applied carefully to minimize non-target impacts.

Physical and mechanical controls can be very effective against some pests, including hand picking, diligent banging of tree limbs to dislodge fruit-eating or leaf-eating insects, a good shake of plants, and trapping or swatting. Bacillus thuringiensis, a bacterium that has been genetically engineered to have insecticidal activity, can be applied to the foliage or fruits of plants to kill pests without damaging the plant. Integrated Pest Management plans consider all these methods and apply them in a balanced fashion, using chemical control only as a last resort.

Pathogens

Pathogens are microorganisms — bacteria, viruses, fungi and protozoa, for example — that cause diseases. Infections by these organisms result in symptoms such as fever, swelling, bleeding or infection. These organisms can invade the body from contaminated soil, water or food, or through sexual contact and bites from insects infected with a pathogen.

They can evade the human body’s natural defense systems and multiply, often causing disease in humans and other mammals. The severity of these infections varies from mild to life-threatening. Bacterial pathogens often produce toxins, which attack and kill cells or interfere with the function of those cells. Examples include tetanus, anthrax and botulinum toxin.

Plant-eating pests may be killed or suppressed by weather conditions, such as freezing temperatures or drought. Many birds, reptiles, amphibians and fish feed on pests and help control their populations.

Fungi can cause diseases in plants by producing chemicals that attack or inhibit a plant’s growth. Fungi also produce polysaccharides, pectic enzymes and hormones that alter the plant’s physiology.

Viruses, which are smaller than bacteria and fungi, can cause diseases in both animals and plants. These viruses generally attack the lipids, proteins, and nucleic acids in cells. They can also cause cell death, which can kill the entire plant or part of it.

Viral infections often cause a variety of symptoms including fever, rash and inflammation. Some viruses can also interfere with the immune system, resulting in autoimmune diseases like lupus or the common cold.

Many viral infections spread through direct skin-to-skin contact, sneezing or coughing, which sends microorganisms into the air, or by touching something contaminated with germs, such as a needle used for injections. Some of these microorganisms can travel directly into the bloodstream, causing infections such as HIV or Ebola.

Some pathogens, such as the fungal disease Batrachochytrium dendrobatidis (Bd), have extirpated whole species of frogs and other amphibians. This disease, however, shows little sign of decreasing in virulence as it continues to infect new host species. The fungus Bd has a wide range of hosts, and some species — such as the widespread African clawed frog, Xenopus laevis, or the American bullfrog, Rana catesbeiana — carry the disease asymptomatically.