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The Effects of Propoxur on American Cockroaches

American cockroaches are the largest species of roach that invade dwellings. The insect grows to about 2 inches long and has a dark reddish brown coloring. Most pest-control professionals will fight a cockroach infestation with a variety of tactics, but one of the most common is Baygon, which has an active ingredient called propoxur. This pesticide attacks the insect's nervous system and, in addition to being used against cockroaches, has largely replaced DDT for fighting mosquitoes.

  1. Application

    • Propoxur is generally applied in particle form to areas where cockroaches tend to inhabit or to any cracks and openings they may use to enter a building. The pesticide sticks to the cockroach's legs when it walks through the particles, and penetrates its exoskeleton. It is also sometimes used as an active ingredient in sprays, baits and traps.

    Effects

    • Propoxur kills cockroaches by shutting down the insect's nervous system. It is known as a "carbamate" that inhibits cholinesterase. When cholinesterase is not produced, synapses fire continuously, causing the organism to twitch and then lose all ability to conduct electronic impulses in its nervous system. The roach ceases to move, then dies. This happens quickly, one reason propoxur is a popular pesticide for fighting fast-moving pests such as the American cockroaches.

    Toxicity

    • Carbamates do not just inhibit cholinesterase in insects. The effect of shutting down the nervous system can happen in most animals, including humans. While licensed professionals do not apply the pesticide in sufficient amounts to poison the air, direct contact with propoxur is toxic and potentially deadly. The initial symptoms of exposure to propoxur in humans resemble the flu: nausea, dizziness, headache, sweating, vomiting, etc. Cramps and muscle tremors indicate a serious dosage. Propoxur should be kept away from small children and pets.

    Resistance

    • Resistance to propoxur is a known problem in German cockroaches, the smaller cousin of the American cockroach. In areas where the pesticide has been used extensively, its ability to penetrate a roach's exoskeleton and shut down the nervous system is more limited than it used to be. However, American cockroaches have a different life cycle and breeding pattern, and are not known to have built up immunity to propoxur like German cockroaches.

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