I clearly don’t spend enough time in the woods. Otherwise, my first encounter with a stump stabber would not have taken place inside my home. This western giant ichneumon wasp (Megarhyssa nortoni) was looking for some grubs deep inside decaying wood so it could parasitize them. Unfortunately for it, my home offered slim pickings.
The female stump stabber has an amazingly long ovipositor which is used to insert eggs into wood-boring grubs deep inside a tree. The hatched egg will then devour the living grub, leaving the vital organs for dessert.
The stump stabber searches for grubs deep in the wood by drumming its antenna on the surface. This windowsill proved a disappointment—no grubs here.
Such beauty and delicate structure and design we find in nature.
Does the female retain the ability to defend herself with a stinger?
Dave, nope. While the stinger has evolved from the ovipositor (so only female wasps and bees sting), this wasp is only capable of using the ovipositor for depositing eggs.
While following up on this topic, I found the following factoid on the Missouri Dept. of Conservation site.
“A great deal of mystery surrounds the method used by the megarhyssa to penetrate wood with its ovipositor. Many scientists believe ichneumon wasps force their long ovipositors into a tree by following cracks and crevices in the wood.
A group of researchers have found some evidence that the tips of the ovipositors may be hardened with ionized manganese or zinc, like metal drill bits. Their studies are not yet complete, but their work suggests that the wasps could be using metal “tools” to drill into wood.”
Dave, wow, I am impressed.
I’ve seen these often but never in the woods, more open spaces like old farm buildings and decaying woodpiles. They are beautiful..ok.. I may be a bit odd. lol