In many cases, removing the food, water, and shelter that pests need can reduce their numbers without using chemicals. This includes weeding regularly, properly placing and removing garbage, fixing leaky plumbing, and storing food in sealed containers.
Threshold-based decision-making focuses on prevention, suppression, and eradication. Prevention means keeping pests from becoming a problem; suppression means reducing their numbers to an acceptable level, and eradication means killing them all. Contact Facility Pest Control now!
Insects (or bugs) are the world’s most abundant group of organisms. They are found almost everywhere except in the seas and ice-covered areas. Insects have one or two pairs of wings and some have horns, antennae, eyes, or other organs that distinguish them from other animals. They undergo a complete metamorphosis, transforming through egg, larva, pupa, and adult stages.
Although insects can have negative impacts, they are important parts of ecosystems as pollinators and decomposers. Insects also act as disease vectors and have been domesticated for food, fiber, silk, and honey.
Some insects cause plant damage and are considered pests, such as aphids that defoliate crops, western flower thrips that transmit peach x disease, or cabbage worms that destroy greenhouse tomatoes. However, insects can also be beneficial in crop production. For example, ladybugs and green lacewings consume aphids, scale insects, mealybugs, and mites that destroy plants. Greenhouse growers rely on these insects to reduce their aphid populations and help them maintain healthy crops.
In addition, insects recycle organic matter and aerate soil. Some, such as ground beetles and dung beetles, break down animal waste and reduce methane emissions on livestock farms. Others, such as crickets and grasshoppers, aerate soil and disperse seeds. Some, such as wood ants and tarantula hawks, provide valuable crop protection services by preying on defoliator and other pest insect species.
The most serious diseases transmitted by insects are mosquito-borne, such as malaria and yellow fever; ticks and lice that transmit typhus and relapsing fever; and fleas that carry relapsing fever and typhus. Insects can also transmit bacterial diseases, including tuberculosis and cholera.
Many insecticides have been developed to kill unwanted insects. They are most effective when used according to the directions on the label. The labels on these insecticides provide detailed information about the use, safety precautions, and environmental concerns. The Experiment Station recommends that gardeners or farmers choose the most environmentally responsible products available for a specific situation.
Rodents
The rodents (genus Rodentia) are a large and diverse group of mammals. Rodents include species such as mice, rats, squirrels, voles, and lemmings. They are herbivores that munch on seeds, bark, leaves, and fruit. They can be active during the day or nocturnal. Some rodents, such as the beaver and muskrat, are semi-aquatic. They have membranes that stretch between their front and hind legs to help them glide.
Rats and mice are opportunistic and will enter homes, buildings, or structures for food, water, or shelter. Look for droppings and gnaw marks near entry points and corners. Look also for grease marks which are dark oily stains from rats chewing on surfaces along their travel ways and in wall voids.
Domestic and wild rodents can transmit diseases to humans. These diseases may be transmitted from their urine, saliva, or droppings, or from fleas or ticks that have bitten them. Rodents can also damage or destroy property and crops.
Native rodents are important for maintaining the health of grasslands and forests. They serve as prey for predators and scavengers, including cats, snakes, hawks, owls, foxes, and bobcats. They also spread seeds and spores and fertilize plants. However, pest rodents such as the Norway rat and the roof rat can cause major problems by infesting houses and damaging or spoiling foods. They can also injure or kill native animals and crops, and contaminate human food supplies.
There are many effective non-chemical methods for controlling rodents, such as trapping, baiting, blocking, and exclusion. Avoid attracting rodents to your home by keeping food stored in sealed containers, and making sure that trash is securely tied. Keep attics, crawl spaces, and cabinets free of paper, fabric, and other materials rodents can use to make nests. Seal entry points with caulk, steel wool, or 1/4” x 1/4” metal mesh. Check plumbing vents, foundation walls, and exterior doors for cracks and openings that rodents can use to gain access. Also, inspect your stove and refrigerator for signs of gnawing on the motor or sides of the appliances. Check paw pads for crusts, debris, or alopecia from excessive grooming that indicates illness/disease.
Pathogens
A pathogen is any microorganism, virus or substance that can cause disease in a host organism. The host may be plants, insects, animals or humans. Some pathogens, like bacteria and fungi, can produce toxins to kill their hosts; others can evade the host’s immune system by encapsulating themselves in a hard coat or secreting proteins that mimic healthy tissue, for example. Most diseases that affect humans are caused by pathogens, such as shigella dysentery from the bacteria Shigella sonnei or Shigella flexneri or typhoid fever from the bacteria Campylobacter coli or V. cholerae.
Pathogens are found in many places, including wastewater and soil. Wastewater contains a wide range of pathogens that can survive long periods of time. Soil may contain pathogens from sewage, animal waste, fertilizer or other sources.
Insects, like plants and other animals, can be infected with bacteria, fungi, protozoa, nematodes or viruses that reduce their rate of feeding, inhibit reproduction, or cause them to die. These naturally occurring diseases, known as pathogens, can be important natural controls of insect pest populations, especially under certain environmental conditions. For example, the bacterium Bacillus thuringiensis produces a toxin that disrupts the nervous system of some types of insects, causing them to feed less and reproduce slower. Formulations of this bacterium, which is also called Bt, are widely used by gardeners and commercial growers as a natural insecticide.
There are two kinds of pathogens: obligate and potentially pathogenic. Obligate pathogens are microorganisms that can only reproduce in a host. Viruses are also obligate pathogens because they cannot grow on their own and must infect other organisms to reproduce. Essentially, a bacterial or fungal pathogen must be obligate in order to be harmful and virulent in order to cause disease.
Biological control of pests aims to introduce beneficial organisms into the environment where they can suppress the population of a destructive species. This approach is usually referred to as biological pest control, a term that includes the use of parasitoids and predators. Inundative pathogens are another form of biological pest control that releases a biological agent into the field to kill off the target pest in a burst.
Natural Forces
The use of natural forces – predators, parasitoids and pathogens – to control pests is referred to as natural control. Any predator, parasite or pathogen that reduces a pest population below a level capable of causing economic damage is considered a natural control agent. Natural enemies are usually biotic (living) species, but can also be natural plant diseases or soil organisms such as the nematode Steinernema.
Most natural controls occur without direct human intervention. These natural predators, parasitoids and pathogens are continually working to help keep nature in balance. Unfortunately, they are often wiped out by broad-spectrum pesticides, and then become the primary cause of increased pest populations and damage.
Many natural enemy species hibernate during winter in non-crop habitats and may enter crops during early season field colonization. In a diversified landscape, these generalist predators and parasitoids are more likely to be found in the field and may significantly suppress pests.
The climate also affects pests directly and indirectly. Extreme weather events such as floods, frosts, or drought can decrease pest numbers and damage by killing or suppressing their hosts. In addition, normal weather patterns – especially temperature, day length and humidity – affect the rate of pest reproduction and development and can limit the growth of their host plants.
Other factors that influence pest control include landscape features such as mountains and lakes, which restrict the spread of many pests, and limiting factors such as overwintering sites or places to hide from predators. Also important are the quality and quantity of food available to the pest, competition among different species for the same resources, and environmental conditions such as sunlight, wind and soil moisture.
Biological control – the introduction of natural enemies that are normally found in the pest’s native habitat to reduce its population and damage – is an effective and economical way to control many pests. It can be accomplished by conservation of existing natural enemies, search and introduction of new natural enemies to the pest’s environment – either to establish a permanent presence in the area or by mass rearing and inundative release of a naturally occurring predator or parasitoid – and by periodic release of pathogens that kill or suppress the pests.