Beware of Giant Toe-biting Water Bugs, Rangers Warn

The National Park Service has warned hikers to beware of a members of the Belostomatidae family of insects who can bite. Santa Monica Mountains National Recreation Area/Facebook

The National Park Service has warned members of the public to watch out for a giant water bug that bites humans.

On its Facebook page, the Santa Monica Mountains National Recreation Area shared a photo of a male abedus herberti carrying eggs on its back.

So-called toe-biters, formally known as abedus herberti, are the biggest member of the hemiptera family of freshwater insects. They can grow up to four inches long.

Most commonly found in North and South America, northern Australia, and East Asia, they inhabit streams and ponds. In some parts of Southeast Asia, the insects are considered a delicacy.

These insects live in the streams of the Santa Monica mountains and can deliver "very painful" bites, ranger Ana Beatriz wrote in the Facebook post. Although their nip is not dangerous, it is believed to be the most painful of all insect bites. The resulting sting can last for several hours.

When frightened, the creatures can play dead and release a smelly fluid from their anus, before reawakening to attack.

Belostomatidae are predators who stalk their prey. Their diet ranges from aquatic invertebrates to snails, crustaceans, fish amphibians and—in rare cases—baby turtles and water snakes.

To catch their prey, the insects lurk motionless in water. When their meal walks past, they strike: piercing and injecting their food with a saliva. After a few minutes, they suck out and eat the remains.

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In 2011, a photograph of a water bug devouring a baby turtle made headlines. Dr. Shin-ya Ohba, of Nagasaki University, snapped the photo in western Hyogo, central Japan.

He told BBC News at the time: "Everyone thinks that Lethocerinae bugs live on fishes and frogs. Although eating a turtle and snake are rare in the natural condition, [this evidence] surprises naturalists [by showing] voracious feeding habits."

Unusually, the male Belostomatids carry the eggs until full term, keeping them moist and protecting them from other predators. After depositing the eggs, the female sets off to find more mates.