Permethrin, Fertility, and Bees

Pyrethrins are natural insecticide/insect repellent produced by chrysanthemums. Permethrin, a synthetic pyrethrin is becoming a popular retail product. In addition to Genetically Modified Corn producing its own "Round Up" there have also been GM varieties that produce their own pyrethrin insecticides like chrysanthemums. However, studies suggest that at non-lethal doses, pyrethrin and permethrin may in fact stimulate insect fertility.

The stimulation of insect fertility may be responsible for the Colony Collapse Disorder of the Honeybee. It turns out that Colony Collapse Disorder most likely is a result of infestation of hives with several types of mites including Verroa and Acarine (tracheal) mites that parasitize the bees and also are vectors for several viral and fungal infections. The Permethrin-producing GM Corn may be actually stimulating the fertility of these mites which then parasitize the bees.

Of interest is a natural cure for honeybee mites. You simply mix Crisco with sugar. When the mites eat the Crisco shortening, the trans-fatty acids kill the mite and cure the bee. This information comes from a display at the Science Museum, Fort Discovery in Augusta, GA. By the way, this display on bee mites was next to another display explaining the military use of PSYOPS.

This treatment could also work for scabies and may be an important alternative to the traditional permethrin. There have been a few case reports of permethrin causing scabies to become invasive. The resultant "super scabies" also called Morgellons can be very debilitating. Also, like in the case of bees, mites can be the vector for fungus ( Pseudococcidae, Microsporidia) which can be the vector for viruses (Hudson River Virus).

If this wasn't enough. Permethrin soaked bed nets do a terrible job keeping mosquitoes away and preventing malaria. Just ask my brother-in-law who just contracted malaria last month while in Ghana. DDT always did a much better job controlling mosquitoes. However, DDT was ban for a while because it was found to inhibit estrogen and progesterone. Together with permethrin which turns out to inhibit testosterone, sperm counts and overall fertility rates are plummeting in developing nations.

Endocrinology, doi:10.1210/en.2006-1497, April 26, 2007. Permethrin May Disrupt Testosterone Biosynthesis via Mitochondrial Membrane Damage of Leydig Cells in Adult Male Mouse

Our results suggest that insecticide permethrin may cause the mitochondrial membrane impairment in Leydig cells and disrupt testosterone biosynthesis by diminishing the delivery of cholesterol into the mitochondria and decreasing the conversion of cholesterol to pregnenolone in the cells, thus reducing subsequent testosterone production.


Braz. J. Biol. vol.65 no.2 São Carlos May 2005. Effect of sub-lethal concentrations of permethrin on ovary activation in the predator Supputius cincticeps (Heteroptera: Pentatomidae)

the lower number of oocytes per female from nymphs exposed to other concentrations of permethrin suggests that this insecticide may affect the reproductive capacity of this predator.

Journal of Economic Entomology 102(1):170-176. 2009. Stimulatory Sublethal Response of a Generalist Predator to Permethrin: Hormesis, Hormoligosis, or Homeostatic Regulation?

Although the sublethal responses to such compounds are sometimes neglected, stimulatory effects associated with low doses of compounds toxic at higher doses, such as pesticides, have been widely reported in recent years and recognized as a general toxicological phenomenon. Evidence of such stimulatory response has also been reported among mites and a few insect pest-species exposed to pesticides and recognized as a one of the potential causes underlying pest resurgence and secondary pest outbreaks... Here, we reported the stimulatory effect of sublethal doses (ranging from 0.02 to 172.00 ppb in addition to the control) of the pyrethroid permethrin topically applied to third instar nymphs of the spined soldier bug, Podisus distinctus (Stål) (Heteroptera: Pentatomidae).

Biol Res 38: 31-39, 2005. Fertility and life expectancy of the predator Supputius cincticeps (Heteroptera: Pentatomidae) exposed to sublethal doses of permethrin

This indicates a higher rate of population increase of this predator when exposed to this permethrin dose.