Stinging and Biting Bugs of Summer

Stinging and biting insects, including mosquitos, black flies, and wasps, are an inevitable part of summer in the Santa Monica Mountains, especially following a wet winter. 

There are a bewildering number of mosquito species, ranging from the evocatively named “foul water” and “treehole” mosquitos, to the ominously titled Southern California malaria mosquito. Most feed on human blood and several are potential vectors for disease, including West Nile virus. 

According to Los Angeles County Vector Control, three new invasive mosquitos may pose greater health threats than existing species. The Asian tiger mosquito (Aedes albopictus), yellow fever mosquito (Aedes aegypti) and Australian backyard mosquito (Aedes notoscriptus)—species with the potential to transmit a number of serious illnesses, including Zika virus, dengue fever, yellow fever, and chikungunya— have begun to spread into Los Angeles County.

So far, none of these species have been documented in the Santa Monica Mountains, but Vector Control is asking residents to help keep the threat from spreading by checking to make sure there are no sources of stagnant water around the house. 

Regularly cleaning birdbaths, maintaining pools, and making sure openings to septic systems are securely covered can help eliminate mosquito breeding areas. Mosquito fish can be used to keep ornamental pools free of mosquito larvae, but only if the pond isn’t connected to a natural stream or creek.

Canyon and mountain residents also have to put up with another class of blood-thirsty pest, biting flies. Unlike mosquitos, which use a syringe-like mouth to suck blood, biting flies are equipped with slashing, scissors-like mouthparts. Bites are instantly painful. 

There are three common biting flies in the Santa Monica Mountains; two belong to the black fly family, the buffalo gnat (Simulium virgatum), which gets its name from its hunched shape, and the infamous punkie (Culiccoides occidentalis) better known as the “no-see-em.” 

Etymologist Charles Hogue, author of “Insects of the Los Angeles Basin,” describes the bite of the miniscule punkie as “far out of proportion to the size of the biter.” Victims may experience, in Hogue’s words, “a short-lived inflammatory swelling followed by intense itching, which may continue for a week or longer. In some cases, the bites may cause a water-filled blister to form.”

Buffalo flies and punkies are most active on warm, overcast days, and tend to congregate in still air in the shade. Scheduling walks or outdoor activities for late afternoon when the sea breeze comes up can help avoid encounters. Although many humans and pets are sensitive to biting black flies, neither species is known to carry disease. 

Anyone who has ever owned horses or other livestock is familiar with the other local biting fly, Tabanus punctifer, the Western horsefly. The bite of this voracious insect is extremely painful and can make life miserable for horse and rider. 

Bait traps are widely regarded as the best way to eliminate biting flies without harming the environment. Topical deterrents range from the effective but also potentially toxic DEET, which masks the smell of the wearer, to preparations made from lemon eucalyptus oil—also effective but not as long lasting.  

Because black flies are weak fliers, an electric fan can help prevent them from being active in outdoor living spaces. According to the American Mosquito Control Association, fans may be helpful in preventing mosquito bites as well.

Horseflies are more robust and less likely to be affected by a fan, but they are large enough to spot and swat. A spray bottle full of vinegar and water and a squirt of dish soap is a popular non-toxic horsefly pesticide for household use.

While honeybee populations are declining at an alarming rate, bee stings are common during the summer, and there is no shortage of other stinging insects in the Santa Monica Mountains, including numerous bee and wasp species.

Bees often congregate on the wet sand at the beach. Wearing water shoes can help prevent one of the most common local bee-sting scenarios. The sting area should be examined, because the sting is barbed and can remain in the wound where it can continue to pump venom.

The Western yellow jacket wasp, sometimes mistaken for a bee because of its size and coloring, is by far the most common and most aggressive stinging insect in the area. Underground colonies of this wasp can number in the thousands and, unlike bees, which can only sting once, yellow jackets can sting over and over again. 

Traps can be used as a non-toxic control for yellow jackets. Keeping food and drink covered when eating outside and making sure open beverage containers haven’t attracted an unseen wasp, can help reduce unpleasant encounters. 

Using care when mowing, digging or weeding in the garden is also advisable. Huge numbers of angry yellow jackets can emerge from a nest in the ground that has been disturbed. 

Although there are numerous native wasp and bee species equipped to sting, including mud daubers, paper wasps, carpenter bees, ichneumon wasps and even the red and furry velvet ant (really a flightless wasp), most are non-aggressive if left alone. Even the tarantula hawk, which has the distinction of having one of the most painful stings in the wasp family, rarely stings unless it accidentally comes into direct contact with a human.

Wearing loose, long-sleeved, light colored clothing can reportedly help prevent bites and stings from a wide range of insects. Avoiding perfume and scented personal care products may also help reduce insect encounters.

Sting-related fatalities are relatively rare—the Centers for Disease Control reports that out of the many thousands of people stung by insects each year, only an estimated 90–100 in the United States die as a result of allergic reactions. However, immediate medical attention is essential if the sting victim begins to experience hives, swelling of the tongue and throat, difficulty breathing, rapid pulse, nausea, diarrhea or dizziness. 

Many biting and stinging insects are essential pollinators and a key part of the local ecology. Being aware of them and taking safety precautions can help prevent unwelcome encounters, but won’t stop all bites or stings from occurring.

An EpiPen is essential equipment on all outings for anyone allergic to bee or wasp stings, but even without an allergic reaction a sting can cause serious irritation and pain.

Ice is considered the most effective home treatment for the pain and itching of bites and stings. Other traditional home remedies include baking soda paste and even toothpaste. 

Hydrocortisone cream and calamine lotion are popular commercial remedies. A topical analgesic like lidocaine may also help. Stocking a fresh supply of sting-related first aid supplies in the car, daypack or beach bag can help make summer vacation less painful and more fun.

Suzanne Guldimann

Suzanne Guldimann is an author, artist, and musician who lives in Malibu and loves the Santa Monica Mountains. She has worked as a journalist reporting on local news and issues for more than a decade, and is the author of nine books of music for the harp. Suzanne's newest book, "Life in Malibu", explores local history and nature. She can be reached at suzanne@messengermountainnews.com