This gorgeous insect is a Giant Ichneumon (Megarhyssa macrurus). They are found throughout most of the United States, as well as Southern Canada and Mexico. They are large relatives to wasps with a body length up to 2 inches. The females are much longer with their ovipositor factored in. The one pictured here is a female. They use that long extension (ovipositor) not for stinging, but for depositing eggs within decaying stumps. After mating, the female will seek the larvae of another insect called a pigeon horntail (tremex columba) which are found in rotting wood. She will then drill that ovipositor into a stump, log or other piece of wood and lay her eggs on the horntail larvae. Depending upon the depth of the larvae she is after it may take her up to an hour to reach her quarry and lay her eggs. I always wonder how the female "knows" that the horntail larvae are even present. Do they hear the vibrations of the larvae as it tunnel through the wood? Do they feel them as they move under their feet? Is there a subtle change in the density of the wood that they can feel with their antennae? However they do it, it sure is amazing.
Impressive and very beautiful critters...I watched one very carefully and deliberately investigate the surface of a tree before finally deciding that she'd found the right place to insert her ovipositor. She was still there an hour later when came back to check on her.
ReplyDeleteThis is the only one in the wild I have ever seen. When I first spotted it I had no idea what it was, as it would not land long enough to allow me to get a really good look at it. After about 2 hours of following it around, losing it, and then spotting it again it finally landed and I realized what it was. She was truly a beauty. I am certain she was after the horntail larvae in the stump in my yard, even though I did not see her oviposit.
ReplyDeleteNice shot, Shelly. It's always kind of amazed me that they can insert those long and relatively flimsy ovipositors into a log -- even a rotten log -- at all.
ReplyDeleteThanks Marvin, I know exactly what you mean. I've been curious about that as well. As I always say Mother Nature is amazing. I'm just glad they aren't prone to sticking it through us!
ReplyDeleteFast---I had to do a google translation of what you said.....here it is for those of who do not speak or read Chinese (Difficulty is not a new concept, but rather to avoid the old concept.) Thank you for stopping by, and your words, truly are words to live by. :o)
ReplyDeleteYou are right that a Ichneumon wasp isn't prone to inserting its ovipositor into us. Unlike many other wasps, its ovipositor isn't used as a defensive weapon. However, one evening I did some primary research by letting a female of one of the smaller species crawl around on my arm and discovered that they will insert the ovipositor into flesh and that some also inject venom along with her eggs. It was a mild sting, but I haven't been inclined to repeat the experiment.
ReplyDeleteOh Marvin you are so much braver than I would be. Experiments like that are not something I'm inclined to try, too big of a chicken.
ReplyDeletehaha Thanks for the post (I have only seen one Ichneumon before), and thanks for the "experiment," Marvin. I probably would have tried to pick one up next time I saw it (if possible), but will now avoid doing so!
ReplyDeleteYou welcome, just look at all the valuable info u get here....LOL.
ReplyDeleteNow you know to not pick up the cousins to these lovely bugs...:o)