Most Americans, including many Army and Marine Corps officers, do not realize how important the adequate provision of excellent insect repellents and insecticides is to the health and morale of our soldiers — especially to those infantrymen who may have to fight in the humid tropics. Most of the lessons learned by our jungle infantrymen and medical specialists in World War II and Vietnam have been largely forgotten. Only a small minority of our present leaders know much about the advantages that can be attained by properly using permethrin insecticides/repellents and improved DEET insect repellent.

Because much can be learned from past successes and snafus that have befallen insect repellents and insecticides, in particular “612” and DDT, this chapter first summarizes their development and uses before and during World War II and in the Vietnam War. It also reviews recent progress involving permethrin and related irrational prohibitions decreed by the Environmental Protection Agency. Facts are given on the increasing danger from the new drug-resistant strain of malaria which has been spread by infected UN peacekeepers and refugees returning home from Cambodia. Anti- malaria drugs are becoming less and less effective. This increases the importance of providing excellent insect repellents and insecticides, especially permethrin and related compounds.


The first effective insect repellent I ever used was “612” (1-3, ethyl hexanediol), issued to me in 1940 when I joined a small party of other Standard Oil of Venezuela exploration geologists. We were working south of the Venezuelan Andes in jungle so insect and disease ridden that it had very few inhabitants. With “612” on my face, neck, and hands during my first day of geological mapping in the humid tropics, I did not realize how effective that repellent was for protection from a small swarm of what I thought were hovering black gnats. Those hard-shelled little pests could not bite through my untreated stout khaki shirt and trousers, but when a sudden onset of diarrhea forced me to quickly lower my trousers and squat I soon felt a stinging sensation all over unprotected bare skin that I could not see. Slapping at what my native porter belatedly warned me were “jejen,” I immediately pulled up my trousers, cursing myself, an experienced outdoorsman in other climes, for being a babe in the jungle. Americans in Venezuela called those little pests “bloodblister gnats”; actually they were one of several species of black flies, daytime flyers.

By the time I got back that evening to our mobile mule camp and my hammock with its zipper-closed sandfly net, I was walking straddle-legged. The three experienced exploration geologists in the party were especially amused at the condition of my swollen scrotum, decorated with blood-red spots surrounded by inflamed, bluish skin. One of them laughingly remarked that the U.S. Army could use a colored photo of it to warn soldiers to avoid diseased prostitutes.

When one of those vicious black flies bites a person who has not developed a partial immunity to its toxin, a bright red, small bloodblister results, surrounded by swollen skin. Natives of that pestiferous part of Venezuela and other persons who have been bitten many times by “jejen” (pronounced “hay-hen”) feel stung, but get only tiny, dark red spots and insignificant swelling.

As a boy both in Texas and in the Philippines I had used citronella, a sharp-smelling oily repellent made from a southern Asiatic grass, for protection against mosquitoes. Citronella had been the Army’s insect repellent for decades, and was used in many countries. However, it was not nearly as effective as “612” for greatly reducing the numbers of insect bites, including those of the mosquitoes that transmit malaria. So, after I had volunteered for active duty and eight months before Pearl Harbor was heading jungle equipment development and testing in Panama, I bought standard 2-oz. bottles of “612” for the volunteers in the first Jungle Platoon of the Panama Mobile Force. Later, shortly after the Japanese overran the Philippines, I was ordered to Washington to advocate the adoption of improved jungle items. By that time I had reports on jungle mosquito-bite tests. The reports were written by medical and infantry officers in the Panama Canal Zone and confirmed the superiority of “612” over the Army’s citronella.

Those bite-test figures did not impress Colonel Stone (I do not remember his full name), the medical officer in the Army’s Office of the Surgeon General responsible for measures to control malaria and other diseases transmitted by arthropods. When I started to explain the advantages of “612” insect repellent, he cut me off short by stating that “612” was toxic and caused severe skin irritation. I countered by saying that thousands of civilians had used “612” in the humid tropics without contracting skin troubles, and asked what toxicity tests he and the Army were relying on. Colonel Stone said the backs of several rabbits had been shaved and various amounts of “612” had been applied, with resulting injury to the rabbits’ skin. I replied — too undiplo-matically for the good of my advocacy — that a rabbit has a much more delicate skin than a man and does not sweat, so substances applied to its skin are not partially washed off. I went on to state that malaria is really toxic to men and would sicken or kill thousands of our soldiers fighting in the tropics, that Standard Oil and other civilian companies operating in malarial regions had excellent doctors who would not continue to recommend “612” if it were toxic, and that it was wrong for the Army to refuse to adopt “612” because it was toxic to shaved rabbits. None of this influenced Colonel Stone, who was much annoyed by my lack of respect for him and other established Army authorities.

For many years I had been a friend of Major General Raymond W. Bliss, who during all of World War II was the foresighted and forceful Surgeon General of the Army. His only son, Raymond, Jr., was my best friend at Texas Military Institute, had been wounded during the defense of Corregidor, had survived a death march, and was a Japanese prisoner for the duration. So the day after seeing Colonel Stone I was able to talk with General Bliss and give him the unofficial mosquito-bite test reports from Panama comparing citronella and “612.” He and other medical officers had realized for months that the Army needed a better insect repellent. They promptly evaluated the Panama field test information on “612” and reviewed its extensive use by civilians in several countries. Within a few weeks the Army began buying and issuing “612” in quantities that totalled millions of bottles before the end of World War II.