Weekly Puzzler Answer #151

If you’re easily grossed out by insects with gruesome life cycles, this post might not be for you. The insect pictured in last week’s puzzler was a kind of Ichneumon Wasp, a parasitoid insect. In the world there are more than 24,000 species of ichneumon wasps(some sources cite more than 60,000); In North America, there are 5,000 species.

That VERY long “tail” at the end of the insect’s body is actually an ovipositor, or egg laying instrument. Females have dramatically long ovipositotm2-rs that are often much longer than the insect’s entire body.

The most amazing thing about this wasp in my opinion is its remarkable ability to locate a good spot to lay her eggs. To have success she must lay an egg INSIDE the body of another insect–be that the larva of a beetle, caterpillar, bug or other invertebrate.  She first lands on the outside of a tree, dead or alive, and uses her long antennae to feel the tree and listen to what’s under all of that thick bark. Amazingly she listens for vibrations to detect where a fat grub of a beetle is feeding deep beneath the bark. She then turns around and maneuvers her body into a position that allows her to drill into the bark and lay her eggs INSIDE the body of the grub. When the larvae hatch out, they feed on the grub, eating it alive from the inside out!

Yikes. I told you it was gruesome! Some kinds of ichneumon wasps select specific prey and some are more generalists. It can take a female over a half an hour to drill more than 4 inches into the solid wood of trees!

The wasp larvae will continue to feed on the grub or other insect larva until it is time to transform into an adult, at which time the host insect is dead or close to dying.


A different species of ichneumon wasp laying eggs


A giant ichneumon wasp laying eggs

Check out a video of this amazing wasp, laying eggs deep inside the bark of a giant tree, into the larva of a wood wasp:

Here is the next puzzler–another insect, but thankfully, without such a gruesome lifeclycle. See if you recognize it.

…and have a fabulous weekend! See you again soon.

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