8 Different Types and Categories of Pesticides

Pesticides are used to control and kill pests such as insects, fungi, weeds, and other organisms that can damage crops. There are five main types of pesticides: insecticides, fungicides, herbicides, rodenticides, and antimicrobials.

An insecticide is a pesticide that kills or controls certain kinds of insects. Fungicide is a pesticide that kills or controls certain kinds of fungi.

Herbicide is a pesticide that destroys plants or inhibits their growth so they don’t interfere with the production of food by farmers either for human consumption or animal feedstock production.

Rodenticide is a substance used for killing rats, mice, etc., while antimicrobial refers to substances that prevent the growth and development of microorganisms including bacteria spores.

Types of Pesticides

The different types of pesticides include herbicides, insecticides, rodenticides, fungicides, bactericides, larvicides, and algicides, which have been discussed in detail here below.


Herbicides are pesticides designed for controlling unwanted plants. They are commonly used in the home garden or farm where there is a problem with weeds that compete with desirable crops.

Do herbicides have negative effects on humans or the environment? Yes, herbicides can have negative environmental effects depending on the type of plant they are targeting, how often it is applied, and where it is poured onto.

Herbicides can affect organisms when they are in liquid form by entering their system when they drink water. The liquid herbicide also competes with oxygen for use in photosynthesis with other aquatic lifeforms such as algae.

This further reacts to create toxins that eventually move up the food chain killing larger animals via biomagnification. Herbicides may be toxic to humans if ingested orally.


Insecticides are a family of chemicals designed to control insects. Most insecticides work by poisoning the nervous system or interfering with metabolic processes. Insects undergo chemical changes when they eat poison – this is how they die.

The affected organs in bees are their digestive tract and nervous system, so preventing feedings leads to death.

Some insecticides do not target vertebrates, but the general population would not be at risk because it’s too expensive for most people to buy these products off the shelf. Most pesticides affect only specific types of insects.

For example, plant crops may be sprayed with one type that is toxic against chewing insects, while an area around animal pastures may be sprayed with another type that sucks blood from the livestock.


Fungicides are used to control fungal plant diseases. They can be natural or synthetic compounds, but they all work by disrupting the cell membranes of fungi so that the organism cannot survive.

Fungicides are typically designed to kill or inhibit spores as well as intracellular organisms such as chytrids and zoospores.

It usually takes four applications over an extended period before significant protection is observed against a particular disease form or severity rating on a crop.


Rodenticides are toxic substances, often in the form of bait, for use in eradicating rodents. Rodents find these bait and often die from eating them or by pest-control agents laying traps that prevent rats from entering buildings.

Some rodenticides work using anticoagulants to disrupt blood clotting; this causes uncontrolled bleeding which can be fatal if untreated. These types of poisons include brodifacoum and coumadin (anticoagulant) such as warfarin (warfarin).

Other toxins kill by administering a high dose of histamine unexpectedly. The most common example is zinc phosphide tablets including devices such as gopher/vole sticks or fox jaws.

I know this is something that comes up often, but I would like to draw attention to the fact that poison, in general, can be extremely dangerous for wildlife.

The only time I would recommend using rat poison in your yard or buying it in stores is when you know you have a large population of rats and they are causing havoc (i.e.: forcing you out of your home).

It’s safer and more effective to find an animal control company or pest removal service with experience dealing with rodent problems.

These professionals will use traps, not poisons, and they will also take any carcasses away after catching their prey so as not to attract other rodents.


Germicides are a type of chemical used to kill unwelcome organisms such as bacteria, viruses, and fungi. The most common types of germicide agents include chlorine, nitrates, alcohols, and acids

Germicides can be classified into two types. They are biocides that destroy only living things or sanitizers that disinfect inanimate objects by destroying many other microorganisms although not necessarily all of them.

Germicidal means having the property to kill various forms of microorganisms including bacteria, fungi, and other single-cell organisms which cause disease in plants or animals – germ is another word for any form of microorganism. The word may also refer to antimicrobial substances.

What are the most common types of common household germicides? Germicidal soaps, gels, or cleansers. All these contain chemicals that cause infections to be killed, including antimicrobials like triclosan.

They often give off lots of fragrance and don’t leave any notable residue behind on things they touch. Germicidal hand sanitizer – With alcohol-based formulas these typically come in finger pump containers.

Though they can also come in spray bottles like you’d use for Lysol or Clorox wipes. They’re good for individual disinfecting but not much else.


Algicides are essential to kill the algae that cause all your hard work of cleaning up after the pool. Algae come in two forms – blue-green and thread-like. It’s easy for both types of algae to grow, especially in warm water over 75°F (24°C).

They can either come out of nowhere or be introduced by someone who used soaps, an earring, a toy, or some other device that contains chemical contaminants.

It doesn’t matter how many times you clean your pool with chlorine, bromine, or saltwater; unless you take care of the algae problem at its source somehow – during or soon after it starts developing – it will continue to slowly but inexorably grow in the pool.


A bactericide is a drug that kills bacteria or inhibits their growth, either by stopping plant cell walls from forming or blocking some essential process needed for the cells to reproduce.

Some common medicines and antibiotics fitted as bactericides: Hospital-grade antibiotics such as cefazolin and gentamicin; glycopeptides such as vancomycin; quaternary ammonium compounds like benzalkonium chloride, hexamethonium chloride, methenamine silver nitrate; alcohols including ethanol (usually in gaseous form) and octenidine acetate.

It’s important to note, however, that many of these substances are not true bactericides.


Larvicides are insecticides that are designed to kill larval mosquito species.

Mosquito larvae are the youngest, smallest stages in the development of these insects. They live in still water that cannot be walked through or dipped into, requiring chemical intervention for their extermination.

Mosquito species that exhibit this aquatic form of life tend to have long hairs called setae on their legs that trap air bubbles under them when they stand or rest on the surface of still water where they may feed off algae and other microbial organisms living there.

This allows them to breathe oxygen from the top layer of an otherwise stagnant body of standing water, even when it is very thin in depth. Glyphosate is one larvicide chemical often used to kill mosquito larvae.

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