Females, which are considerably larger than males, have a stout spine projecting from the hind end. They will not sting. This is the ovipositor, used to insert eggs under bark. Mine had a body about 10 cm (2") long, including the various extremities she was huge. They can be 85mm (3 ½" long), including their ovipositor. It is quite a spectacle. They are able to detect pigeon horntail larva through the bark of the dead or dying tree. Update: April 8, 2014 We are frequently asked if Giant Ichneumons can sting, and we always reply that they cannot. There are thousands of them. She was looking for holes bored by her rival, a pigeon horntail wasp. Each oviposition event can last more than 40 minutes making the female wasp vulnerable to many threats during that long period of time. Then I went inside to look up what it was. Ovipositor is inserted fully and retracted about halfway back a number of times. When the female finds one, she drills into the wood to reach the larva. The ones shown here are probably the species Megarhyssa macrurus. The other is the most common natural enemy of this insect, the giant ichneumon wasp (Megarhyssa macrurus). Oviposition must be energetically very exhausting. Females have a very long (up to 3 inches long) thread-like egg-laying structure (ovipositor) on the end of their abdomens. Petfinder, meet bugfinder.Specifically, a bug so big, so creepy, so like-the-alien-in-Alien-looking, that when I saw it crawl out of a fist-sized hole in a tree near Britannia Beach, it made me ski… Do not panic; they will not harm you. During our trip we came across an egg-laying female of Megarhyssa macrurus. The female’s ovipositor is therefore not a stinger, but an organ used to inject eggs into the larva’s host. Megarhyssa macrurus macrurus (Linnaeus) is similar in size to M. m. lunator, but the body and wings are dark brown. Giant Ichneumon Wasp: Long-tailed (Megarhyssa macrurus) Detailing the physical features, ... tube-like ovipositor is not a stinger and cannot sting. Many males may gather at the site where a female is about to emerge. We just found a fascinating article. They travel up and down a tree stump, looking for grubs, then deposit eggs in the grubs, and the wasps larvae live off of the host grubs, eating the grub, leaving vital organs for last. Two large and bizarre looking insects are commonly associated with dying branches and trunks of several commonly grown hardwood trees. Press J to jump to the feed. Talk:Megarhyssa macrurus. They are parasitoids: their larvae develop as parasites living inside the body of other insects. This is a male Giant Ichneumon in the genus Megarhyssa. The long flexible ovipositor is used to drill deep into dead or dying trees to deposit an egg into the body of a wood wasp or horntail larva. After laying her egg next to the larvae of the pigeon horntail, she will sting the larva, paralyzing it. Megarhyssa macrurus) Detailing the physical features, habits, territorial reach and other identifying qualities of the Giant Ichneumon Wasp: Long-tailed.