Insecticides are usually very strong substances in their pure form. To make them easier and safer to use, manufacturers turn them into different types of formulations, which can still be very strong, containing up to 80% active ingredients. The main goal of using insecticides in pest control is to make sure they come into contact with the pests, but this should be done without risking harm to people or pets. Sometimes, as little as 5 or 10 grams (or even less than 1 gram) of active ingredients need to be spread out in a building the size of an average home. Choosing the right application equipment and using it correctly helps ensure the insecticide is distributed effectively and controls the pests.
How insecticide is applied is a crucial aspect of safely and effectively controlling insects with chemicals. It’s important to have a good understanding of the habits and biology of the pests involved.
Types of Insecticide Application
The are several ways to apply insecticides to ensure that they reach the target pests and effectively control them. In general, most pest control methods in urban areas can be classified into four types, depending on the type of pests and their behaviours:
- Using baits to treat pests;
- Spraying arrears with insecticide to control flying insect pests;
- Applying insecticide to surfaces to control crawling insects;
- Fumigatiing to control insects inside materials.
Baiting Treatments
Baiting is becoming more popular in urban pest control, particularly for dealing with cockroaches, ants, and termites. Common types include paste and gel baits that come in ready-to-use syringe-like cartridges, making them easy to load into applicators.
These systems often come with various accessories, such as different dispensing lips (like crack and crevice extension tips), and in some cases, they include an attachable torch and holster for easier use. There’s no need to mix chemicals on-site, and bait products are getting more attractive and effective for the pests they target.
Space-spray treatments for control of flying insects
Flies, mosquitoes, certain moths, beetles, and other flying insect pests can be controlled well using different types of spray treatments. These treatments involve breaking down a liquid insecticide into small droplets that stay in the air for a while. The insecticides often used in space-sprays are typically quick at knocking down insects but do not leave a lasting effect. They are broken into small droplets using different methods: thermal foggers use heat, cold foggers physically break up the liquid, and aerosols use compressed gas energy from low-pressure or high-pressure systems.
Space-sprays are typically used in big areas like homes or warehouses, where the spray droplets must come into direct contact with insects. Some sprays, like dichlorvos, can easily turn
into vapour to kill insects by inhalation. To make sure the insecticide works well, the area treated with space sprays is usually closed p to prevent the spray from running off of windows or other openings. These treatments need the building to be empty while they are being done, and they should be aired out before people go back in. Some people who suffer from asthma or hay fever might be extra sensitive to these sprays, so it is good to consider ways to control pests.
Using too much or using dichlorvos incorrectly as a space spray can lead to significant issues such as:
- Health risks for people inside the building. When misused, dichlorvos can get absorbed by materials like plastics and then release harmful vapours over time, which can affect the people in the building.
- Damage to items like plastics because dichlorvos has strong solvent properties.
Use dichlorvos as a space spray only when suitable, like in warehouses, and only by trained operators who understand the risks involved.
Formulations with high levels of oil-based solvents, like kerosene used in some fogging equipment, may:
- Need precautions due to the flammable atmosphere they create, such as turning off pilot lights.
- Cause surface contamination and staining in the treated area.
Space sprays can help control crawling insect pests in two ways:
- Some insecticides can get into the hiding spots where these insects live.
- Certain types of space spray equipment have long nozzles designed to reach cracks, crevices, and other hiding spots where these pests hide.
In simpler terms, space sprays work by releasing a small amount of liquid insecticide into the air as tiny droplets. These droplets mainly target flying insects. However, they can also reach the juvenile stages of flying insects, which do not fly, as well as flying insects at rest. This helps control them even though they are not crawling insect pests.
Surface treatments for control of crawling insects
To deal with crawling pests like cockroaches, silverfish, ants, bed bugs etc., surface spray treatments are used. These involve applying liquid or solid insecticide directly onto surfaces where pests are likely to crawl. The insecticides used are usually long-lasting and can remain effective for days, weeks, or even months, depending on the type of insecticide and pest situation.
There are three methods of application:
Dusting Treatment
Dust is applied using different equipment, from small hand puffers for treating tiny spaces behind cupboards to pressurized devices for treating entire roof spaces. It is used in hard-to-reach areas where pests like cockroaches hide, such ass cracks, crevices, wall voids, and roof cavities. Fine insecticidal dust spreads well, ensuring thorough treatment in hidden spots.
Surface-spray Treatment
Liquid insecticide is sprayed onto surfaces in a coarse, wet mist, typically until the surface is just about covered. Once any diluents like water or solvents evaporate, the insecticide remains behind as a deposit. This method targets surfaces where pests are likely to rest, feed, or move around, such as cracks and crevices. Space-spray treatments can be applied using various equipment, from handheld pumps to larger power sprayers connected to tanks. Different nozzle setups offer different spray patterns. When choosing an insecticide, we also consider its potential to stain surfaces, for example, when treating materials like carpets for fleas.
Higher-volume, surface-spray treatment
A liquid insecticide is applied onto the soil in a coarse, wet spray to soak the soil. This helps deal with insects that live in the soil, such as subterranean termites. By saturating the soil with a stable insecticide, it creates a barrier or ‘toxic zone’ that remains effective for months or even years keeping pests at bay.
Fumigation treatment for control of insect pests inside materials
Insects that eat through wood or grain can be tough to control with regular surface treatments. Instead, we use fumigation, which means using special gases to get rid of them. These gases go deep into the materials and kill the bugs by getting into their breathing system.
To make sure fumigation works well, we need to have a high concentration of the gas. We achieve this by either using a special chamber (like for bugs in furniture) or by sealing up buildings or containers tightly (like when we wrap buildings in plastic to kill termites).
The gases used for fumigation are very strong and dangerous. That is why only trained and licensed pest technicians should do fumigation work. They know how to handle these chemicals safely.