WHAT IS PYRETHRUM?
by Dr. Fred Preiss, Director of Research & Development at MGK®

Pyrethrum is a botanical insecticide produced primarily in the flowers of Tanacetum cinerariaefolium, a species of the chrysanthemum plant family. Pyrethrum plants have historically been grown in commercial quantities in Kenya, Tanzania, Rwanda and Papua New Guinea. Over the past decade, Tasmania and Uganda began producing pyrethrum. Today Kenya and Tasmania are the largest pyrethrum growing and producing countries.

In East Africa the mature pyrethrum flowers are picked by hand, sun dried to remove moisture, and sent to a processing plant for extraction of the active ingredient-pyrethrins, a mixture of six closely related esters. In Tasmania the flowers have been bred to synchronously flower so they can be mechanically harvested. As in Africa , the flowers are sun dried and processed to extract the insecticide pyrethrum.

Pyrethrum is an ancient insecticide. The insecticide properties of the flowers were documented in the early 1800’s but it is suspected that the flowers were used to kill insects a considerable time earlier. The first commercially available products were powders made from ground flowers and later crude oil extractions became popular. Today, the refining of crude pyrethrum extract to remove the plant material, waxes, etc. is a highly complex process resulting in a very high grade product.

Pyrethrum has been used effectively to control insects for decades and is non-persistent, decomposing rapidly in the environment. This rapid degradation of pyrethrum has resulted in little known cases of insect resistance making it an excellent choice for the control of agricultural pests.

PyGanic™ Crop Protection Products from MGK contain a new and unique form of pyrethrum and are listed by the Organic Materials Review Institute (OMRI) for use in organic production. Pyganic was the first pyrethrum-based product to be listed by the OMRI for use in organic farming. Through proprietary technological advances, MGK has successfully developed a product that is compliant with organic standards and maintains all the desirable attributes of pyrethrum flush, rapid knockdown, kill and rapid degradation.

PyGanic is effective in killing over 40 agricultural pests and is approved for use on over 200 crops and ornamentals. A few of the more important pests controlled by PyGanic include; glassy winged sharpshooter, Colorado potato beetle, stink bug, aphids, thrips and loopers.

Upon first hearing about the application of misting for mosquito control, the first question most people ask is, "Does it work?" The second question is inevitably, Is it safe? That is why before you get serious about whether or not to purchase a MistAway system, it is important that you understand what the insecticide is, what it is not and how to safely use it in your system.

DERIVED FROM FLOWERS, BUT NOT "NATURAL"
The active ingredient in the insecticide used in MistAway systems is comprised of a family of chemicals called pyrethrins, which are derived from the extract of chrysanthemum flowers (pyrethrum). Though its origin sounds natural, it is not correct to think of pyrethrin-based insecticides as either "natural" or "organic" because, in addition to being highly refined, they usually contain a man-made synergist. A synergist is an additive that enables the insecticide to be more effective than it would otherwise be. Pyrethrins act as contact poisons, affecting the nervous system of insects. So, they rid the property of mosquitoes and other annoying insects primarily by killing rather than repelling them. Pyrethrins are not species selective and their contact will also kill beneficial insects like bees and butterflies. Fortunately, these insects tend to be active during times when most mosquitoes are not. Pyrethrins are rapidly degraded by sunlight or by rain, leaving the yard free of residual active ingredients. Because some plants exhibit sensitivity to direct application of some pyrethrin-based insecticides, nozzles should be placed where they do not mist directly on those plants.

PYRETHRIN SAFETY
Pyrethrin-based formulations are considered by the EPA to be "general use" insecticides, meaning that homeowners can buy and use them without a license. They are one of the least poisonous insecticides to mammals. In fact, pyrethrins are important ingredients in products commonly found in many homes. Household aerosols and pet shampoos are good examples. But, they are poisons. While they are low in toxicity to people and pets because the body quickly breaks them down, it is not a good idea to come into close or frequent direct contact with the mist. Inhaling pyrethrins can cause respiratory problems (coughing, wheezing, etc.) and skin contact can cause a rash or itching. Pyrethrins are highly toxic to fish and tadpoles and should be especially carefully applied around water.

MAN-MADE BOTANICALS
The downside to pyrethrins’ natural origin is they can be expensive (requiring labor intensive chrysanthemum harvesting) and may be subject to shortages in supply caused by bad weather that can make them even more expensive. In response, scientists have developed synthetic forms of pyrethrins, called pyrethroids that work in the same way. Like pyrethrins, a synergist is added to them to make them more effective. Pyrethroids are less expensive than pyrethrins and are an important ingredient in the insecticide "cocktail" used by municipalities and counties to control mosquitoes. An important difference between pyrethroids and pyrethrins is that the man-made pyrethroids are not as readily degraded by sunlight and therefore leave a lasting residue. Another important difference is that mosquito populations are already showing signs of resistance to the man-made pyrethroids, but there is no evidence yet of resistance to pyrethrins.

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