As we enter the month of May a season dreaded by all backcountry enthusiasts in the Adirondacks quickly approaches. Only the heartiest (or craziest) hikers and backpackers venture far into the backcountry during the height of the bug season in May and June. And with the recent abundant rainfall overflowing the lakes, ponds and streams there should be a bumper crop of biting and blood-sucking insect pests to torment anyone unwearyingly stepping out into the outdoors without the proper preparation and protection.
A menagerie of four different types of flies form the core of the biting or blood sucking community within the Adirondacks. These four blood-sucking flies of the Adirondacalypse are black flies, mosquitoes, no-see-ums (or biting midges) and deer flies.
These four pests have much in common. They are all flies with biting or piercing mouth parts used to satisfy a thirst for something humans have in large supply: blood. Typically, only the female flies feed on our blood (sorry ladies!), which they need to produce their eggs. Most of the time males and females feed on nectar. Water plays an important role in the life cycle of these biting insects, which probably accounts for their abundance in the Adirondacks. In addition, these menaces of the north woods may be vectors for wide range of diseases but this does not seem to be a big issue in the Adirondacks (at this time).
The bane of all backcountry explorers in the Adirondacks during the spring are black flies. These voracious little flies prefer areas near running water where they lay their eggs. They are active only during the day but are less so on windy days. These little devils have cutting mouth parts used quite effectively to obtain the required blood meal necessary for reproduction.
The cutting mouth parts leave a little red mark on the skin that can swell and itch intensely. Scratching the area can intensify the itching and lead to infection in some cases. Some people seem to be more susceptible to the effects of the black fly bites probably due to an allergic reaction to the fly saliva.
Hordes of black flies are active from May through July depending on location and elevation. They exist in such large numbers that the term “Adirondack wave” has entered the vernacular to describe the act of swatting these hordes away from the face. Although treatments of streams with Bti (Bacillus thuringiensis israelensis) has brought a measure of relief near some settlements, in the backcountry no such control of black fly population exists.
The buzzing of mosquitoes is a common sound heard throughout the backcountry anytime from spring to fall. Although these flying fiends tend to be crepuscular they can be active at anytime during periods of high humidity. Mosquitoes have piercing mouthparts and therefore tend to leave the least impact from their feedings. Although mosquitoes lay their eggs in standing water they can often be found far from any water.
Mosquitoes use carbon dioxide and other organic substances to locate hosts although humidity and optical recognition play important roles. They can be vectors for many different diseases most not present within the Adirondacks with the possible exception of West Nile Fever.
If you feel a burning pain about the face but cannot see anything biting then you may have just become a blood meal for no-see-ums (or biting midges). These minute cousins of black flies typically are only 1-4 mm in length but what they lack in size they more than make up in ferocity. Their bites can cause small intensely itching red welts that may persist for days.
No-see-ums typically are crepuscular even more so than their mosquito cousins. They seem to be especially active during warm and humid periods such as after heavy dew or following a light rainfall.
Deer flies are present near open areas and seem to prefer warmer temperatures and sunnier conditions than their other blood-feeding compatriots. The females use their knife-like mandibles to cut through human flesh leaving a cross-shaped incision. The bite of these flies is quite painful but luckily they typically occur in smaller numbers and require more time to prepare before slicing and dicing our flesh. Pain, itching and swelling are common reactions to their saliva but more significant allegoric reactions are possible.
Deer flies tend to alight at or near the highest point on their prey and therefore they can buzz around one’s head for what seems like hours. From my experience they prefer royal blue and this color should be avoided when selecting outdoor gear. Birders need to be especially careful with these critters as they often strike the hands when raised to use binoculars.
There are two types of defense against the onslaught these flies wage on the human race in the backcountry. Physical defenses can be used in the form of certain clothing, bug nets and gloves. Chemical defenses require saturating one’s skin with any assortment of concoctions ranging from those based on natural ingredients to those of highly toxic solvents.
Physical defenses require using a barrier to physically block access to your body from these pests. The most commonly used physical barrier is the head net. These nets are placed over the head to keep the biting flies at bay. They should be used with a hat to keep the mesh of the net away from the face. The head net mesh should be black in color to cut down on the glare of sunshine produced with other colors. Also the mesh MUST be fine enough to prevent no-see-ums from penetrating.
Long pants and a long sleeved shirt are a good defense during the height of bug season. Gaiters are a must when black flies and no-see-ums are active since they often find their way up the pant legs. Gloves can be useful but are often too hot during much of bug season. Some people resort to duct taping gloves to their shirt to avoid any penetration by the most persistent of these pests. Since deer flies tend to land near the highest point on their prey a hat with a brim all the way around will help keep them from biting your head.
Outdoor manufactures do not appear to take biting flies into account when they design their products given the propensity of unnecessary mesh-lined pockets, inappropriate colors and ineffective fabrics. Clothing fabric requires a very tight weave in order to prevent mosquitoes from penetrating. Also, normally impenetrable material can become vulnerable when it is pulled taught against the skin.
Chemicals can be a quite effective defense against the horde of biting insects especially during hot days when covering one’s self with clothing can be uncomfortable. Insect repellants are either based on synthetic chemicals or natural ingredients. Typically, the synthetic chemicals require fewer applications than their natural ingredient counterparts.
The most common synthetic chemical repellant is DEET (N,N-Diethyl-meta-toluamide). It is a commonly used repellant and is very effective in repelling most of the biting insects of the Adirondacks. But be warned, DEET is a strong solvent and can dissolve some synthetic fabrics so be careful when applying it.
Picaridin, IR3535 (an active ingredient in Avon’s Skin So Soft) and Permethrin are also effective repellents. Unlike DEET, Picaridin does not dissolve plastics and therefore may be a better choice for any backcountry explorer decked out in synthetic attire. Although Permethrin has low human toxicity (but it is highly toxic to cats and fish) and is not readily absorbed into the skin, it is usually applied to clothing where it remains effective for up to six weeks.
There are several natural repellant ingredients with varying levels of effectiveness. Citronella oil, oil of lemon eucalyptus and cedar oil are all natural-based insect repellents effective against the insect pests found in the Adirondack. In my experience these natural insect repellents need to be reapplied more often than their synthetic counterparts.
A promising new natural insect repellent is nootkatone, an extract found in the Alaskan yellow cedar trees and citrus fruit. This chemical has the benefit of being completely nontoxic; in fact, it is often used as a natural flavoring in many foods. It is currently years away from being produced into a commercially available product.
Although swarms of vampiric flies can cause much misery during bug season they should not be used as an excuse for avoiding the backcountry. With the proper preparation and protection bug season can be enjoyed or at the very least tolerated. These bugs and their accompanying bites should be thought of as the price of admission for venturing into the backcountry.
Photos: Mosquito by Center of Disease Control (CDC).
Dan Crane blogs about his bushwhacking adventures at Bushwhacking Fool.