Tree of the Year, 2016 - Megarhyssa atrata

HomeGuideID RequestRecentFrassForumsDonateHelp

Clickable Guide

Calendar

Upcoming Events

Registration is open for the 2024 BugGuide gathering in Idaho July 24-27

Moth submissions from National Moth Week 2023

Photos of insects and people from the 2022 BugGuide gathering in New Mexico, July 20-24

Photos of insects and people from the Spring 2021 gathering in Louisiana, April 28-May 2

Photos of insects and people from the 2019 gathering in Louisiana, July 25-27

Photos of insects and people from the 2018 gathering in Virginia, July 27-29

Previous events

TaxonomyBrowseInfoImagesLinksBooksData

Home » Guide » Arthropods (Arthropoda) » Hexapods (Hexapoda) » Insects (Insecta) » Ants, Bees, Wasps and Sawflies (Hymenoptera) » "Parasitica" - Parasitoid Wasps » Braconid and Ichneumonid Wasps (Ichneumonoidea) » Ichneumonid Wasps (Ichneumonidae) » Rhyssinae » Giant Ichneumonid Wasps (Megarhyssa) » Black Giant Ichneumonid Wasp (Megarhyssa atrata)

Photo#1327686

Copyright © 2017 MJ Hatfield

Tree of the Year, 2016 - Megarhyssa atrata

100 Acre Wood, Winneshiek County, Iowa, USA
August 22, 2016

First, something about the tree. This is a live Maple tree that Pileated Woodpeckers took a liking to Winter 2015/2016. As of Fall 2016 it still had some live branches.
It has been a source of entertainment, delight and learning since May 30, 2016. It continues to delight. We've dubbed this the Tree of the Year, 2016.
In fact visitors (including the mail man), whether they were interested or not, were walked to the tree to see the life.

May 30, 2016: the first encounter with Megarhyssa (although I have no idea how many days they were around previous to this date).
I guessed (obviously wrong) they would be around for a couple of weeks.
Same day, M. macrurus and M. greenei:

A few highlights:
May 31, 2016: first Ibalia anceps sighting

June 1, 2016: Megarhyssa macrusus

June 6, 2016: click link for movie Megarhyssa atrata ovipositing & finishing up

June 7, 2016: a male M. atrata

June 8, 2016: counted 19 wasps at one time (but couldn't see to the top of the tree)

June 13, 2016: of interest (OK, there was a lot 'of interest') was that the wasps seemed to really like the Pileated holes in the tree for ovipositing.
In fact, some of the smaller holes were shared by more than one wasp at a time

June 18, 2016: Opiliones breakfast

which gave me the idea to check out just how mobile the female adults were while ovipositing

August 10, 2016: last Ibalia anceps sighting, first Tremex columba sighting, emerging from the tree

September 9, 2016: what is left of a Tremex columba. After the husk of the body fell off the tree, the ovipostior remained in the tree.

September 14, 2016: click experiment with Tremex columba

September 15, 2016: one of the several stuck-in-tree ovipositors

September 19, 2016: last Tremex columba sighting
October 3, 2016: last Megarhyssa sighting

should have read these first
Megarhyssa atrata
Ecology of 3 Megarhyssa Species
Thank you Ross Hill. Looks like in 2017 there will be more activity, and if I'm lucky, I'll catch an emergence or two

This is the most complicated series of connected posts I have ever done (and it's not yet finished).
But I finally learned how to spell Megarhyssa!

Update, the next year.
June 4, 2017: a congregation of males, M. atrata

Images of this individual: tag all

Giant Ichneumons - Megarhyssa atrata - female

Giant Ichneumon - Megarhyssa atrata - female

tag · login or register to post comments

Contributed by MJ Hatfield on 2 January, 2017 - 8:22am
Last updated 13 February, 2020 - 7:48pm

Fascinating

that the Megarhyssas were around from May-Oct (!!) and that there was an apparent peak in activity in June. I wonder if this is the usual pattern and if they will return for more ovipositing next year. If they do return it would be interesting to know when they first begin ovipositing in 2017 (i.e., will it be earlier than May 30?).

… John van der Linden, 2 January, 2017 - 9:55am

I'm curious

if earlier they were emerging from this tree.
It's a new year and I will check (but not today).

… MJ Hatfield, 2 January, 2017 - 10:39am

Love it love it love it

!!!!!
This is so great.
Do I see 3 ovipositors in 1 woodpecker hole in that third photo?!?!
MY FAVE: Opiliones breakfast
I've watched such trees briefly before (never over the course of a season), never seen Ibalia.
Did I mention I love it?

… John van der Linden, 2 January, 2017 - 9:48am

Thanks.

I looked at that 3 somethings into the tree hole but couldn't figure out if they were 3 ovipositors. One might be a sheath? I really don't know.

… MJ Hatfield, 2 January, 2017 - 10:37am

Very cool!!!

With only 2 wasps, would 3 ovipositors be possible?

… Marci Hess, 3 January, 2017 - 11:22am

Looking at the photo

I couldn't quite imagine the contortions necessary for the 3rd wasp to have it's ovipositor in the hole.

… MJ Hatfield, 3 January, 2017 - 1:13pm

3 wasps

Hard to see, but note abdomen of 3rd wasp in upper left hand corner of image ;-)

… John van der Linden, 3 January, 2017 - 11:25am

Disclaimer: Dedicated naturalists volunteer their time and resources here to provide this service. We strive to provide accurate information, but we are mostly just amateurs attempting to make sense of a diverse natural world. If you need expert professional advice, contact your local extension office.

Contributors own the copyright to and are solely responsible for contributed content.
Click the contributor's name for licensing and usage information.
Everything else copyright © 2003-2024 Iowa State University, unless otherwise noted.

Bugguide is hosted by:

Printer Friendly Version