QUICK COURSE: Pesticides and what you need to know about them

CHEMICALS are classified into two major groups. Organic and Inorganic

  • ORGANIC chemicals are any that contain the carbon molecule. The molecule can be of either natural or synthetic origin.
  • INORGANIC chemicals are any that lack the carbon molecule. Usually are of mineral origin.

THERE ARE different ways in which both of these chemicals work.

  • STOMACH POISONS are either swallowed by the insects feeding or grooming habits.
  • CONTACT POISONS enter insects either through outer membranes by piercing their surface, or by inhalation through the respiratory tubes (spiracles).

JUST LIKE insects themselves, insecticides have different lifespans.

  • NON-RESIDUAL insecticides carry toxic agents that break down to non-toxic byproducts almost immediately after application. These are usually used as contact kill or flushing agents.
  • RESIDUAL insecticides carry toxic agents that remain active for a relatively long period of time or depending on the actual chemical used, indefinitely.

MINERAL Inorganic in chemistry, and generally used as a stomach poison. Can have a very long residual life. Examples include Boric Acid, Zinc and Sodium Fluoride (Not used in most residential setting).

BOTANICAL Plant extracts; usually used as a contact poison. These have a very short residual life and are safer for the environment. CAUTION botanical insecticides can be very toxic to people and pets.
Examples include:

  • Pyrethrum (Chrysanthemum extract) – non-residual; quick knock down.
  • Rosemary, Thyme, Clove, Cinnamon, Cedar Oils
  • Piperonyl Butoxide (Sassafras extract)- added to insecticides to help conceal toxic effect of insecticide (making insecticides work better without increasing toxicity of chemical).Both examples have lower toxicity levels

SYNTHETIC ORGANIC Chlorinated hydrocarbons such as Chlordane and DDT where some of  the most common used pre 1980's

  • They are usually less toxic than organophosphates and carbimates.
  • Known for extremely long residual life (years not months)
  • Known to build up in body tissue and suspected as carcinogens
  • Most are banned in the United States and many other countries

ORGANO-PHOSPHATES Up until the year 2000, was the most widely used class of insecticide

  • Replaced Hydrocarbons
  • A derivative of WWII nerve agents
  • Ironically more toxic than Chlorinated Hydrocarbons
  • Chlorpyrifos (Dursban), Diazinon, Malathion were most common, voluntarily pulled off the market by manufactures.
  • Known for much shorter residual life and accumulates in body tissue for shorter periods of time, a suspected carcinogen. SPECTRUM PEST CONTROL has never used this class of insecticide.

CARBAMATES Similar to organophosphates in chemical activity

  • Lacks many of the serious side effects of organophosphates
  • Still used today for bee/wasp control
  • Sevin dust is an example.

PYRETHROIDS Synthetic versions of Pyrethrums

  • Some have a longer residual life
  • Most have a lower acute toxicity than table salt* (refer to our Pesticide Labels and what do they mean QC)

INSECT GROWTH REGULATORS-I.G.R. Insect hormones used to prevent insects ability to shed exoskeleton, metamorphosize or reproduce.

  • Can be of natural or synthetic origin
  • Usually non-toxic to mammals while still maintaining toxicity to targeted pest


ORGANIC METHODS are USDA certified for agricultural uses. No official government agency certifies structural pest control methods as organic.

  • Organic pesticides are usually of botanical origin due to their short residual life
  • They can also include Bio-Logical methods that rely on micro-organisms to control pest. (i.e.: bacterium, viruses, fungi, predator’s insects such as lady beetles and praying mantis etc.
  • Chemical methods can include inorganic substances such as Diatomaceous earth and sodium octoborate.

The common understanding of organic is any food or product that is processed or grown free of insecticides, fungicides, and herbicides. In the scientific definition, anything whether it is natural or synthetic that contains the carbon molecule is organic. Anything without the carbon molecule (such as minerals) is inorganic.

The pest control and agricultural industries use the term organic to refer to products, chemicals or methods that do not have a toxic residual life, harmful to people or animals. If you are eating organic food without bugs, an insecticide was used.

Many of the chemicals used today are extracts from Chrysanthemum flowers, Sassafras tree, Derris plant, Diatomaceous Earth from ground-up fossilized diatoms. There are many herbal remedies that include (but not limited to): Garlic, onion, peppers, citronella, citrus oils, lemongrass, cedar oils, cat-nip (not available yet, being tested as an alternative to DEET) etc. Most herbal products more likely act as a repellent than posses killing agents.


Both agriculture and pest control has been moving towards IPM for over thirty years. IPM is where you use a more holistic approach to pest control. IPM first relies on non-chemical, mechanical pest control methods.

  • Monitoring (glue boards, traps etc.) to determine suspected population levels and points of entry. Collected information on infestation levels leads to exclusion/control options.
  • Determine if infestation levels justify chemical options.
  • Exclusion methods include caulking cracks, sealing holes, repairing structural defects, removing debris i.e. environmental sanitation and changes in landscaping methods such as avoiding natural mulches near structures and keeping trees and shrubs away as well.

GREEN METHODS use many of the same approaches used in IPM. However, more emphasis is placed on overall risk to the environment. Green does not mean any chemicals. Green does not even mean only natural or organic chemicals. In many cases, synthetic chemicals can have a lower impact on the environment than their natural counterparts. Many natural products have a low toxicity but require multiple applications to accomplish the same effect as a low toxicity synthetic. Thus their hazard levels can be significantly higher than a synthetic.

CAUTION! Some people are seriously allergic to some natural products. We always screen for known allergies prior to applying any pesticide. Especially when used indoors. Many manufacturers will gladly confirm any risk there may be with their products. You are entitled to a copy of the product label and S.D.S. of any pesticide being used in or around your home or business.