Megarhyssa: the most peculiar looking insects
Sept 22, 2019 0:29:34 GMT
nomad, skandinavisk, and 1 more like this
Post by trehopr1 on Sept 22, 2019 0:29:34 GMT
Here, I have the only extant specimen of this species of Giant Ichneumon Wasp which I have ever encountered in my field work. This species is Megarhyssa atrata. It is largely a black insect with yellow head, antennae, and legs to boot ! Again, those "warning colors" are present. The body of this creature is only about 3" in length however, it's "drill" makes it a most impressive 11" in length !
These seldom seen or encountered insects are widely distributed throughout the Coniferous forest of North America. There are 4 recognized species to date. Of those, 3 of the species M. atrata, M. macrurus, and M. greenei exploit different niches, allowing them to coexist in the same locations and using the same host.
The female Megarhyssa are specialist predators of Horntail larvae. They are so to speak "one of the good guys" that help keep nature in check. You see, horntail females introduce wood-digesting fungi when ovipositing, which helps their grubs extract food value while feeding on the wood. Megarhyssa are able to detect the odor of these fungi through their very sensitive antennae. They will walk about the bark of an infected tree "tapping" the surface with their antennae to further pinpoint the location of the horntail grub within the wood.
Once a grub is located, the female Megarhyssa literally "bows" her greatly extended ovipositor over her back in such a way as to provide "optimum" leverage. She drills slowly into the soft wood and eventually deposits an egg on or near the horntail grub within its burrow. When the egg hatches it behaves as an ectoparasitic parasitoid halting the hosts development and eventually consuming the grub.
Absolutely fascinating stuff here folks...
These seldom seen or encountered insects are widely distributed throughout the Coniferous forest of North America. There are 4 recognized species to date. Of those, 3 of the species M. atrata, M. macrurus, and M. greenei exploit different niches, allowing them to coexist in the same locations and using the same host.
The female Megarhyssa are specialist predators of Horntail larvae. They are so to speak "one of the good guys" that help keep nature in check. You see, horntail females introduce wood-digesting fungi when ovipositing, which helps their grubs extract food value while feeding on the wood. Megarhyssa are able to detect the odor of these fungi through their very sensitive antennae. They will walk about the bark of an infected tree "tapping" the surface with their antennae to further pinpoint the location of the horntail grub within the wood.
Once a grub is located, the female Megarhyssa literally "bows" her greatly extended ovipositor over her back in such a way as to provide "optimum" leverage. She drills slowly into the soft wood and eventually deposits an egg on or near the horntail grub within its burrow. When the egg hatches it behaves as an ectoparasitic parasitoid halting the hosts development and eventually consuming the grub.
Absolutely fascinating stuff here folks...
