Experience in Preventing and Treating Biting from the Three-Spot Ant

Residents in many regions across the country have been very alarmed due to the increasing presence of Paederus insects, which can cause painful stings. Therefore, it is essential for everyone to know how to prevent these encounters.

Learn about Paederus insects

Paederus insects, scientifically known as Paederus fuscipes Curtis, belong to the Staphylinidae family (rove beetles) within the order Coleoptera. This species has a slender, elongated body resembling a grain of rice (about 1-1.2 cm long and 2-3 mm wide), and comes in various colors, resembling ants.

According to Dr. Nguyen Xuan Quang, head of the Entomology Department at the Quy Nhon Institute of Malaria-Parasitology-Insects, Paederus insects contain a toxin known as Pederin (C₂₄H₄₃O₉N), which is 12-15 times more toxic than cobra venom. However, due to the small amount of toxin present and its contact being only on the skin, it is not lethal like snake venom. Pederin can remain in the insect’s body for years; even after drying out and being stored for up to eight years, the toxicity persists.

Paederus insect.

Dr. Nguyen Van Huynh from Can Tho University explains that the Pederin toxin is produced in specialized glands at the end of their abdomen, which protect their eggs from predation. Thus, if the insect is crushed or roughly handled, the toxin can be released and come into contact with human skin, causing a burning sensation and pain.

Where do Paederus insects typically live?

Paederus insects are considered dangerous. The toxin in these insects is 12-15 times more potent than cobra venom, and if not treated promptly after exposure, it can lead to severe complications.

Paederus insects (also known in some regions as: striped ants, golden ants, or rice ants) are characterized by alternating black and orange-yellow bands, with a slender, elongated body resembling a grain of rice, measuring 1-1.2 cm long and 2-3 mm wide. They possess three pairs of legs and two pairs of wings, one pair of which is long and thin, folded neatly under a shorter, hard pair. They are quick in both flight and movement.

These insects typically inhabit rice fields, decomposing grass, orchards, garbage sites, and construction sites. They are most prevalent at the start of the rainy season and are attracted to nighttime light. After heavy rains, when their habitats are flooded, they often fly into homes seeking light and can settle on clothing, towels, bedding, and curtains. Paederus insects secrete a fluid that can damage human skin upon contact.

This species appears at the beginning of the rainy season when humidity levels are high, particularly following heavy early-season rainfall. They often inhabit rice fields, feeding on brown planthoppers, and are drawn to light, frequently swarming around light sources in areas surrounded by rice fields.

The toxin from Paederus insects can cause skin burns, dermatitis, and a burning sensation similar to acid burns. Many people inadvertently use their hands to kill the insects and then touch other areas of their skin, causing damage even in areas where they were not stung.

Injuries caused by Paederus insects typically present as red rashes, blisters, or pustules, resembling sores known as “kissing lesions”, which are characteristic of contact dermatitis caused by insects.

Symptoms of a Paederus sting

• The primary injury appears as red, burning patches, sometimes in clusters or streaks, with a slightly raised surface, small blisters or pustules in the middle, and a yellow-brown depressed area that is circular or oval.
• Dermatitis usually occurs on exposed areas of the body, such as the face, neck, chest, back, shoulders, and arms.
• Injuries may continue to appear even in the absence of Paederus insects if the affected person scratches or rubs healthy skin areas, especially in folds of the skin.
• The affected individual may experience a burning sensation at the site, and if the injuries are extensive, they may have a mild fever and swollen nearby lymph nodes.

Progression of symptoms after a Paederus sting

• After being stung by a Paederus insect, the victim may feel a tingling sensation.
• 6-8 hours later, red patches may appear.
• 12-24 hours after the sting, typical injuries manifest.
• After 3 days, the burning sensation begins to subside, and peeling may occur.
• After 5-7 days, the peeling will be complete, but discoloration may remain for a long time.

Contact dermatitis caused by Paederus insect toxins. (Illustrative image).

Home treatment for Paederus stings

• If you come into contact with the toxin of a Paederus insect, the affected skin may develop redness and itching. Immediately wash the area gently with saline solution to remove the toxin.
• After that, apply a cooling paste to the affected skin to soothe it and prevent blistering.
• If blisters develop, continue using the cooling paste to clean and soothe the skin.
• If the wound shows pus, apply a methylene blue solution to disinfect and prevent infection.
• Once the wound has dried and is no longer oozing, use topical antibiotic ointments with mild to moderate corticosteroids (e.g., fucidin-H, fucicort) to promote healing.
• If the damage is severe, a doctor may prescribe oral medication in addition to topical treatments to prevent severe allergic reactions or secondary infections.

Dermatitis caused by Paederus insects usually resolves quickly within a week if treated properly. However, patients should only gently wash the affected area with saline (0.9%) immediately after contact to neutralize or reduce allergic and irritant factors, and then seek medical attention promptly. Self-treatment should be avoided to prevent more severe complications.

What to do if you come in contact with a Paederus insect?

• Do not crush or rub the insect when you see it on your body to avoid releasing toxins.
• If exposed to the toxin, avoid scratching or rubbing the affected skin. Do not touch healthy skin areas with hands that have come into contact with the toxin.
• Thoroughly wash the contaminated area (especially around the eyes) as quickly as possible if exposed to the toxin, apply medication, and follow your doctor’s instructions.
• If you accidentally crush a Paederus insect with your hand, wash your hands thoroughly with soap as soon as possible to avoid toxin transfer.
• If the skin is red and spreading, seek medical attention; do not self-medicate, as topical medications may contain corticosteroids or detoxifying agents that require a doctor’s prescription.

Ways to prevent Paederus stings

Instead of exterminating them, find ways to repel them from your living environment.

Paederus insects do not actively sting humans and are not disease carriers; thus, they are not as detestable as commonly perceived.

Moreover, Paederus insects are considered beneficial insects and are regarded as allies for farmers. Therefore, it is better to find ways to repel them from your living environment rather than attempting to exterminate them.

Preventive measures against Paederus stings include:

• Keep doors closed to prevent them from entering your home.
• Close curtains to block light that attracts Paederus insects.
• Install insect screens in windows and ventilation openings.
• Avoid using neon lights at night and sitting close to light sources like bulbs.
• If possible, turn on balcony lights to attract Paederus insects outside, preventing them from entering your home.
• When handling Paederus insects, wear gloves or use a soft paper towel; avoid direct contact.

Simple treatment for wounds caused by Paederus without needing a hospital