Backswimmers are common aquatic insects found in various water environments. Known for their unique swimming style, these insects can cause concern due to reports of painful encounters. This article clarifies backswimmer “bites” and offers practical information for identification, treatment, and prevention.
Identifying Backswimmers
Backswimmers are slender, oval-shaped aquatic insects, typically less than half an inch long, with a streamlined body. Their most distinguishing feature is their swimming posture: they propel themselves through water upside down, using long, oar-like hind legs fringed with fine hairs. The back of the insect is often keeled, similar to a boat’s bottom, and is usually light in color, ranging from green to brown or yellowish.
These insects are found in still or slow-moving freshwater environments like ponds, lakes, and marshes, where aquatic vegetation provides something to cling to. Backswimmers also appear in swimming pools, often after night flights, as they are attracted to artificial lights. They are predators, preying on other aquatic insects, small fish, and tadpoles.
The Backswimmer’s “Bite”
While often called a “bite,” a backswimmer’s interaction with humans is more accurately a stab or pierce. They use sharp, tubular mouthparts, known as a proboscis or beak, to penetrate the skin. This action is primarily a defensive mechanism when they feel threatened or mishandled, not an act of aggression or an attempt to feed on humans.
Upon piercing, the backswimmer injects digestive enzymes or toxic saliva. This substance helps them subdue prey by dissolving internal tissues, which they then consume. For humans, the sensation is compared to a bee or wasp sting, causing immediate, sharp, burning pain at the site of contact. The reaction includes localized pain, swelling, and redness, which subsides within a few hours. While the injected substance is not poisonous or life-threatening to humans, it can be quite uncomfortable.
What to Do After a Backswimmer Encounter
Should you experience a backswimmer’s pierce, prompt first aid can alleviate discomfort and prevent complications. Begin by thoroughly cleaning the affected area with soap and water to minimize infection risk.
Applying a cold compress or ice pack can reduce pain and swelling. Over-the-counter pain relievers, such as ibuprofen, may be considered if pain persists or is significant. For more pronounced reactions, an antihistamine could provide relief from itching or swelling. While most reactions are mild, seek medical attention if symptoms worsen, if there are signs of a severe allergic reaction like difficulty breathing or widespread rash, or if signs of infection like increased redness, warmth, or pus develop at the site.
Avoiding Future Encounters
Preventing encounters with backswimmers involves managing their preferred habitats and food sources. In natural water bodies, exercising caution in areas with stagnant water or dense aquatic vegetation can reduce interaction likelihood. These environments are where backswimmers are most active.
For swimming pools, regular maintenance is effective. Backswimmers are attracted to pools with algae, which serves as food for other insects like water boatmen, their prey. Maintaining proper chemical balance, including appropriate chlorine levels, and regularly cleaning pool walls and floor prevents algae growth and deters backswimmers. Skimming the pool regularly to remove insects and debris also eliminates potential food sources and habitats. Turning off pool lights at night can further reduce their attraction, as they are drawn to artificial illumination.