Sand Flies of the Caribbean

by Gary Carlson

At some point in any general conversation about Roatan and the other islands of the Caribbean the subject of our mutual aggravation, the Sand Fly, will come up.

Central America, including the island of Roatan, is an Etymologist’s dream. The tropical jungles, with endless warmth and humidity make it the perfect habitat for a multitude of insects.  There can be found in the jungles insects so tiny your magnifying glass will need bifocals, along with monstrous beetles, moths the size of your hand, tarantula spiders, centipedes, millipedes, billipedes, and zillipedes.  All this insectish-ness, so strange to those of us from the warming north, fade to minor curiosities once we come in contact with the invisible menace of the tropics.

The Ox Beetle of the Honduras mainland grows up to and inch and a half excluding the horns

Your flight arrives on Roatan in the afternoon. As you disembark the heat and humidity hits you like a hot towel, and even with the speed and efficiency of the Honduran equivalent of the TSA/Customs it seems like forever to get through immigration while your clothes start to stick, and cling. A twenty minute ride in a cramped taxi with questionable, if used, air-conditioning deposits you at your hotel’s incredibly “island time” check-in process. Finally getting to your room, you peel off those winter clothes, get in your shorts and flip flops, grab a beer and head to the beach for the sunset. With what seems to be the longest trip of your life over, you stand in the water’s edge, savoring the accomplishments of the day and the island views while the warm waves lap at your ankles. There is a small and almost unnoticed sting on your calf, and unconsciously you reach down and give it a bit of a scratch, perhaps thinking that your gentle unburned skin may be sensitive to the salt…..

Let me introduce you to the Sand Fly.

Actually a midge, the Sand Fly (sand gnat, sand flea, and no-see-um) is actually a member of the Black fly extended family which brags of having members from the equator to the arctic.  This flying, biting, blood-sucking dipterin (educated for ‘fly’) lives on and near the white sand beaches of Roatan where its eggs are laid in the damp coastal sand. Normally daytime feeders, they are especially voracious in the early hours of the morning and evening. Generally flying close to the ground, our legs from the knees down are the most vulnerable to their bites. Like the mosquito, although research may turn up other earthly organisms, only the female of the species will latch on to you, and steal your vital life forces.  It seems the protein in our blood as well as the blood of other mammals, reptiles and birds is necessary for the production of eggs, making the sandfly an autogenous reproducer.

The bite itself appears as a pink raised circle about the size in diameter of a pencil eraser with a blood red dot in the center, which is a reaction to the inflammatory markers injected during the blood sucking process. These inflammatory markers are the cause of the itching which soon follows. Then when you scratch it, it actually releases more inflammatory markers which make it itchier, and then you tend to scratch it even more so it becomes a bit of a vicious circle.

Some, a small percentage, of people must be very tasty to sand flies, and seem to attract them causing some pretty impressive bite patterns. Although no one seems immune our hearts go out to these rare victims. Hanging out with those who live on the island will make you feel like you are the only one donating to the sand fly’s breeding efforts, because nobody else has those tell-tale spots. In a strange tropical island rite of passage, after a couple of months on the island you no longer get the itch spots and bumps associated with the sand fly bite. You still get to enjoy the moment of puncture, and there is about ten minutes of itchiness, but we’ve paid our dues.

Do not despair fellow divers, and travelers! There are preventions and cures that knock this pest back to being a minor distraction.

Increasing populations on Roatan have taken over some of the Sand Fly’s habitat, and preventative measures like raking the beaches to expose and dessicate the eggs have also reduced the Sand Fly problem, but nothing is 100% effective.

Insect repellant products containing DEET like Off™ and Cutters™ are very effective in the avoidance of these pests. DEET (N,N-diethyl-meta-toluamide) was developed by the US Army in the forties and released for a grateful public’s use in the mid 50’s, it is still the most effective way to avoid interaction with these pests.  While the Sand Fly is attracted to the heat signature of our bodies, it is the CO2 given off by our skin and breathing that really attracts them. DEET works by masking this CO2 and our desirability as munchable. There are many “natural” products which exist that also offer protection, among them is the locally produced and available Aegis products, which we find to be quite effective.

I have lived here ten years, and I have to be reminded of the flies, however avoiding them has become such a habit that I don’t even think about it. In the morning before I leave the house I apply the repellant product of my choice on my legs from the knees down. If I am going out in the evening I do the same. That’s it, no problem. Lying out on the beach? I don’t do that, but if I were to give in to the urge, I would encompass a greater area, such as head to toe.

However if you do lapse in your vigilance there are no end of cures available. Suggested during the extensive research that accompanies every issue of THE BLOG as methods of alleviation are/ but not limited to; cold and cooling gels, heat with a blow dryer or hot pack, Vicks Vapor Rub, Calamine Lotion, Tea Tree Oil, Aegis repellent (also itch relief), Benadryl™ orally and as lotion, hydrocortisone cream, and the ever popular Rum which is often the inspiration of new cures.


The Sand Flies on Roatan, although troublesome at times are no worse than pests in other areas. I personally have experienced the incessant flies of Australia, the bomber sized mosquitoes of Alaska, the White Sox of the Yukon, the ticks of the Rocky Mountains and who knows whatnot smeared across the windshields of various journeys. It only goes to show you that no matter where you go, there will be something there, be it flying insect, crawling bug, or elected official, ready, willing, and able to suck the life’s blood from you.

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