Are Deltamethrin Insecticide Sprays dangerous? What do they kill?

The first line of defense against pests within and outside of homes is typically insecticide. It is easy to use, is generally safe towards humans if not directly breathed in or ingested, and offers a quick kill to any insect imaginable. Deltamethrin belongs to the most popular class of insecticides–pyrethroids, which are some of the most widely used insecticides in the world due to their generally low toxicity to humans and mammals.

What are Deltamethrin insecticide sprays?

Deltamethrin insecticides belong to the pyrethroid group of chemical pesticides, which are synthetic chemicals derived from chrysanthemum flowers. With low-toxicity to humans, these insecticides are safe alternatives and kill a variety of insects.

Deltamethrin spray works by targeting the central nervous system of insects where it causes disruptive imbalances that stun, paralyze, and kill them. Although some insect species have begun the process of developing resistance to pyrethroids, the sheer popularity and safety of this product cannot be matched in the pesticide industry. With a formulation in many common insecticide brands, this product has a multi-purpose and multi-species efficacy in treating infestations or spot treating annoying invaders.

Is Deltamethrin Harmful to Humans?

What makes this product so popular is not only its effectiveness but also its general safety to humans and pets. Pyrethroids are synthesized from chrysanthemum flowers, which are beneficial to humans and animals as an alternative form of medicine; however, side effects can be present and the same rule applies to pyrethroids such as this product. Most of the time when administering this product and others like it, we avoid heavily breathing in the chemical or ingesting it, but in some cases, irritation and reactions can occur if these situations arise.

If this product is ingested or breathed in, reactions such as nausea, dizziness, and headaches are common. If the symptoms consistently persist, a call to poison control or even a visit to an emergency room would be advisable since heavy ingestion or inhalation of the product can be mildly toxic.

When exposed to skin, Deltamethrin can cause itchiness, redness, and even allergic reactions, therefore it is always advisable to administer this product with gloves, a respirator mask for pesticides, and be sure to wash your hands when finished.

Is Deltamethrin a Carcinogen?

It certainly merits caution when wondering if insecticides are carcinogenic due to the chemical formulations. Thankfully, deltamethrin is not carcinogenic to humans. The basis for this product is rooted in natural substances which are then synthesized for maximum effectiveness, which is what likely attributes this product as non-carcinogenic.

What Insects Does Deltamethrin Kill?

Deltamethrin kills a large variety of insects both indoors and out. Since the mechanism of death is targeted at an insects central nervous system, the versatility of this product is evenly spread over numerous varieties of pests. Although many flying insects can be killed by direct contact, it will likely be essential to buy formulations of the product that can be administered as long-lasting residuals, such as powders and dust.

Some of the most common insects susceptible to Deltamethrin include:


  • Ants
  • Bed bugs
  • Cockroaches
  • Mites
  • Fleas
  • Flies (all varieties)
  • Gnats
  • Scorpions
  • Millipedes
  • Moths
  • Ticks
  • Carpet beetles
  • Spiders
  • Termites


  • Wasps
  • Bees
  • Worms
  • Centipedes
  • Crickets
  • Earwigs
  • Beetles
  • Fire ants
  • Mosquitoes
  • Yellowjackets
  • Sowbugs

How to Administer Deltamethrin

When administering the Deltamethrin, it is important to know the behavior of the insect in question. For flying bugs, the product is best used as a contact spray, especially for clusters of flying insects.

For pests within the home, the product should be applied to all areas where bugs harborage which can vary depending on the insect.

Residual powders, sprays, and dust can be most beneficial as the bugs will crawl through the product over time. Always apply the product to problem areas and be sure to apply to areas that insects may crawl through as well.

Can Deltamethrin Kill Bed Bugs?

When using deltamethrin for bed bugs, it is somewhat a roll of the dice regarding the product’s effectiveness. Bed bugs continuously evolve their DNA to become resistant to commonly used insecticides, of which the pyrethroid-based deltamethrin is one of the chemicals they have developed resistance to. Not all strains of bed bugs have developed this resistance, so this product will certainly work against killing those particular bed bugs.

Since there is no clear way of knowing if a particular strain of bed bugs have developed resistance, deltamethrin for bed bugs should be monitored over time to judge the product’s effectiveness.

Does Deltamethrin Kill Termites?

Deltamethrin has been proven to kill termites, however, the method of application is crucial in utilizing the product’s effectiveness in termite colonies. The best method for killing termites with this product is to administer it as a dusting agent.

Delta Dust is a version of this chemical in a residual, powder form and is a powerful weapon in the arsenal of termite elimination.

Because termites primarily dwell inside of wooden structures, it becomes difficult to treat them with deltamethrin spray; however, a residual dust formulation will ensure that over time the termites will crawl through the chemical and die shortly after.

What Is Deltamethrin Dust?

Deltamethrin is commonly used as a spray, however, when formulated as dust, the mechanism of action changes to address insects that are hard to find. When insecticides are formulated as dust and powders, the residual effects are enhanced by allowing the chemical to lay undisturbed for long periods. Deltamethrin when administered as dust is also odorless, which makes it a virtually invisible weapon against unsuspecting bugs who happen to crawl through it.

Related Questions

Deltamethrin vs Permethrin? Are They The Same?

Deltamethrin and permethrin are virtually identical as both chemicals are synthetic derivatives of pyrethroids. Few differences exist between the two formulations, and both chemicals target the central nervous system of insects. Permethrin has a better efficiency at killing lice in comparison to deltamethrin, but you will likely notice no inherent differences between deltamethrin vs permethrin.

Are Deltamethrins Not killing Your Pests?

As previously mentioned, pyrethroid insecticides are becoming ineffective to some strains of certain types of insects due to resistance development. With bed bugs and termites, easy solutions are never guaranteed when trying to win the battle against these elusive, destructive, and incredibly versatile creatures.

Insects generally do not have many natural defense mechanisms to work with, and perhaps their only true mechanism to survive is their ability to produce antibodies to commonly used chemicals that have been used to eradicate them.

If this product is not working, it may be essential to try and monitor the product's effectiveness on your own by isolating an insect and directly applying the chemical to the bug in a closed contraption. After directly applying the chemical, if a bug is simply stunned, but not killed, this is a clear indicator that this pyrethroid-based pesticide no longer can kill this particular strain of insect.

Is Deltamethrin Harmful to Bees?

When it comes to pests, it is generally not correct to classify bees in this category. Bees serve highly beneficial purposes to our environment and despite occasionally stepping on them or getting stung due to disturbing them–bees generally will not cause much stress in our lives. 

Although this product will mostly only work in repelling bees, there are some bee species that this product is particularly lethal against. Deltamethrin is highly toxic to honey bees, even more so in comparison to other targeted insects.

Does Deltamethrin Harm Fish and Aquatic Wildlife?

Deltamethrin is incredibly harmful to fish and any organism that lives in water. Although it is difficult to avoid the environmental run-off effects that come from using this product, you can take measures to ensure the product does not come into contact with fish both in your home as pets, as well as outside the home in ditches and storm drains. Since fish have erratic nervous systems, the central nervous system antagonist effects of this product will produce similar results as those seen in insects.

Where to Buy Deltamethrin

Deltamethrin is available under many different brands and can be found online and in virtually every retail outlet that sells insecticides. D-Fense SC which is available at Amazon is a pure formulation of this chemical and can be administered through a dilution of water in a sprayer.

Delta Dust is one of the best formulations of the product in dust form on the market and can be purchased from many online retailers.

In Summary

Deltamethrin is one of the most popular and widely utilized insecticides on the market, with a highly effective mechanism that kills insects by targeting their central nervous system.

Once ingested or applied to insects, the chemical disrupts the normal flow in their central nervous system which produces paralyzes and eventual death.

Available as a spray or dust formulation, this product is versatile and highly toxic to insects. Proper application of the product is essential when addressing a certain species of insect, so always base your application in particular specifics to the insect in question.

Deltamethrin is generally safe to both humans and pets and has a low-toxicity in any organism apart from insects and fish.

Multiple varieties of insects are susceptible to this chemical and due to its non-carcinogenic properties, it can be safely administered within the home.

Although Deltamethrin is versatile in killing many insect species, some bugs are developing resistance to pyrethroid-based insecticides, so monitoring the product's effectiveness is critical in determining its usefulness.

As a powerful and inexpensive insecticide with low-toxicity, Deltamethrin will produce results and alleviate your pesticide worries due to its safety.

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