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Predaceous Diving Beetles Seeking Prey

There is a family of water beetles, Dytiscidae, known as Predaceous Diving Beetles.  As their name implies, these beetles are predatory.  They don’t hesitate to attack prey larger than themselves, delivering a sharp bite with their jaws to small fish, tadpoles and frogs.  They then immediately inject enzymes that digest the prey so that the juices can be ingested.

Predaceous Diving Beetle larvae, called “water tigers,” are also predators, grabbing prey with their pincer-like jaws. The larvae are elongated, flattened and can be 2 inches long. They hunt by holding still, waiting with jaws wide open, and then strike suddenly, clutching the prey tightly with their jaws. As with the adults, the pincers are hollow, enabling them to begin sucking the juices of their prey while grasping it. They are often seen when they come to the surface of the water to draw air into spiracles located at the hind end of the body.

Adult Predaceous Diving Beetles are collected by young girls in East Africa. It is believed that inducing the beetles to bite their nipples will stimulate breast growth. Having recently had my toe bitten by a Predaceous Diving Beetle, I can testify that this is not a practice that most females (or males) would enjoy. (Photo: Predaceous Diving Beetle with remains of prey)

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7 responses

  1. Penny

    Yikes! Toes are bad enough!

    July 26, 2019 at 9:01 am

  2. Alice

    🤭😮 interesting info! How ‘big’ are those beetles? Hope your toe is better.

    July 26, 2019 at 9:02 am

  3. Jody Crosby

    Only you could make this bug interesting to me AND make me laugh out loud at the end!

    Sent from my iPhone

    July 26, 2019 at 9:40 am

  4. Omg! Nature (including humans) is endlessly fascinating.

    July 26, 2019 at 11:26 am

  5. Ruth Gross

    Sent from my iPad


    July 26, 2019 at 1:44 pm

  6. Maine naturalist

    I’ve had a toe bitten by a similar species, and under no circumstances would I put it on my nipple. The pain in my toe was enough that the sleeping bag nylon touching it woke me up, and the swelling was great enough that I could barely put my hiking boot on the next morning.

    July 26, 2019 at 3:19 pm

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