Several times during my career as an entomologist, that is someone who studies insects, I have been asked to identify “bugs” which “have been biting” or otherwise creating havoc for their human victim(s). In most cases, these “bugs” turn out to be just that – bed bugs, or occasionally head lice, and the like. In fact, there are many groups of insects and related organisms which are blood feeders that will dine on humans, including (in addition to those mentioned above) body lice, ticks, some mites (e.g., chiggers), mosquitoes, black flies, assassin bugs…and the list goes on. Most of these animals are readily visible with the naked eye, albeit some are quite small. However, they often go unnoticed as some are nocturnally active, and/or try to stay concealed while feeding. Are you itching yet?
There are even some mites which are permanent residents of our bodies; Demodex are small (<0.5mm) mites that are not uncommon, especially in elderly people, the proportion of people serving as homes to these mites typically increases with age. Demodex are found mainly on our face, particularly in hair follicles and are sometimes referred to as “eye-lash mites”. These mites are considered part of the normal body fauna associated with being a mammal, and our relationship is even considered an example of commensalism in most cases. How about now…do you want to scratch your face?
Needless to say, throughout our evolutionary history as a species, we have been the regular feeding trough for some interesting animals; in fact, some of these “companions” of ours have become so specialized on our species that they are now not found on any other. No matter who, or what you are, you are part of a food web…this is nature! Some of our common expressions evidence these ancient relationships; remember hearing “sleep tight, and don’t let the bed bugs bite”? Also common, but perhaps not commonly attributed to being on the menu are phrases like “I’m going over it with a fine-toothed comb” or “stop being such a nitpicker”. Of course, the original use of these phrases referred to the process of removing head lice, or nits, and this activity has been with our species longer than we know…even before we becameHomo sapiens! Our closest relatives, the great apes, make a ritual out of “nitpicking” for hygiene, to build strong family or social bonds, and perhaps for some nourishment.
At the present time, as was also true in the past, many of these unwelcome guests are easily spread from one person to the next, whether by sharing a hat or other article of clothing with a classmate, wearing unwashed used clothing, spending a night in an unfamiliar bed, or through intimate contact, it is easier to pick up these small hitch-hikers than you might think. This may be even truer at the present, as our “global village” practices allow us to travel great distances in a short time, and our bodies and luggage can come into contact with the stow-away(s) of previous travelers. This has been one of the primary reasons offered to explain the recent increase in bed bug infestations in major cities around the world.
As an interesting aside, I would like to use this blog to comment on a seemingly (though not necessarily) related phenomenon…a person exhibiting all the typical symptoms of being fed upon, without the body of the insect to verify the feeding activity. Usually when I get requests to identify insects, they are captured and/or photographed to confirm their involvement. But on a few instances I have received vials, or carefully wrapped “packages” apparently with “biting insects” inside, only to find small specks of dander, lint and other fibres, sand particles, etc. One unfortunate person even claimed that these “bugs” were flying around them. This has not happened that frequently to me, though apparently it is a rather common event for some entomologists, and even those in the health sciences. So, there is this pattern…receiving a package containing small particles attributable to “something” causing itchy, crawling sensations all over the body, red marks and/or sores, and on other occasions, tiny coloured fibres of “unknown” origin that seem to grow out of the skin…without any culprit causing it. Weird huh?
Well, these are not isolated phenomena. In fact, for at least a few of these cases, the victims share some of the symptoms of a condition now called Morgellons by many. In the 1600s, the term was used in France to describe a condition in which children grew coarse hairs out of their back; the recent (i.e., 2001) usage of the term is linked to the symptoms listed above, and the strange coloured fibres. However, the term is not really recognized within the medical profession and in fact, most of the symptoms (minus the strange coloured fibres) are very similar to those used in the diagnosis of “delusions of parasitosis”. Using the internet, one can quickly find many websites, and several articles (including scientific ones) on Morgellons; it may be this ease of self-diagnosis that has caused the increased reports of this condition, numbering in the tens of thousands in North America alone. In the United States, the government has even put some research dollars towards unveiling some of the mystery of this condition. Some in the medical profession believe that self-diagnosis is part of the problem, and others believe it may not be a medical condition at all, but a psychiatric one. One doctor even called it a “socially transmitted disease”, the carrier being the Internet! I will not go on at length on Morgellons as this falls outside of my range of expertise, but invite you to do some of your own research…it makes for an interesting read, and it is easy to sympathize with “its” sufferers.
However, I will add a few more comments on the actual animals that share our tissues. First, coming back to Demodex, it is clear that some people can become sensitive to the activity of these mites, especially if they have a suppressed immune system, though for most of us, they will go unnoticed. “Demodicosis” is the term used for the sensitive cases, and symptoms included itching, inflammation and other skin disorders, linked even to severe acne, and inflammation of the eyelids. The skin condition “rosacea” has also been linked to Demodex, particularly to the bacteria they carry in their bodies. In other mammals, for instance cats and dogs, Demodex are known to cause mange. Like for many things in our world, including much of what we eat, and/or what chemicals we are exposed to, our bodies have not evolved to handle the unnaturally high levels. Our sensitivities to many potential allergens are increasing, and probably will continue to do so. I will save discussion of insect transmitted diseases for another time perhaps, but will add that scratching insects bites can make them worse! If you are being visited by biting insects, scratching the bitten areas can introduce dirt, bacteria, and even some of the frass (insect poop) that was left by your friend, causing infections, red swollen areas, and perhaps worse in the long run. Keeping the area clean and using anti-itch medication should help!
As an entomologist, I do try to help people by identifying insects for them…thus, it is very important to capture them! In alcohol works best, and having individuals of different sizes (ages) helps a great deal. Squashed insects are very hard to identify accurately. Another approach that seems to work is the use of sticky, clear (transparent) tape. Simply touch the tape (delicately) to the bug, and then stick the tape to a clear surface, such as a clear plastic bag. As a curator at a museum, it is also nice to retain material in the collection for future use, so it is important to keep track of where, and when you collected it. Use precautions when you travel and learn to recognize the signs of the presence of bed bugs. Once you bring them home, they can be very difficult to get rid of. Learn to recognize areas where you may pick up ticks, and monitor and treat your pets for fleas and other pests. Lastly, be comfortable knowing that being bitten, and being the host of other animals is part of sharing this planet...it is entirely natural, even if it is a little creepy.