RHoman's picture

Ant-like insect

Observed: 12th November 2009 By: RHomanRHoman’s reputation in InvertebratesRHoman’s reputation in InvertebratesRHoman’s reputation in InvertebratesRHoman’s reputation in InvertebratesRHoman’s reputation in Invertebrates
ant1
ant2
Description:

An ant-like insect found in a recess in the bark of an oak tree. Tree growing in a parkland setting. Insect approx 6mm in length

Identifications
Species interactions

No interactions present.

Species with which Oak Apple gall wasp (Biorhiza pallida) interacts

Comments

Syrphus's picture

This has been up for a couple

This has been up for a couple of days, and I still don't have a clue what it is! The absence of responses suggests I may not be alone. It is not difficult to eliminate a lot of things, but I seem to have eliminated *everything*. Does anyone have a starting point, just to save me more sleepless nights?

M.

TRY

recording wildlife with The Recorder's Year on www.hbrg.org.uk/TRY.html.

charlieb's picture

I'm pretty sure this is one

I'm pretty sure this is one of the wingless ichneumons- but which one...

Syrphus's picture

That is certainly a

That is certainly a possibility I thought about, but the antennae did not seem right. There seem only to be 14 segments, while my key to the Ichneumonoidea says >16. That is a group I tend to pass by on the other side, though - for very good reasons!

M.

TRY

recording wildlife with The Recorder's Year on www.hbrg.org.uk/TRY.html.

RHoman's picture

Possibly Biorrhiza pallida

Thanks to those of you who suggested an ichneumon. The brain clunked into action and I sent the pictures to a friend who had an undergraduate interest in that group and he has come up with the very plausible suggestion that the insect is a female Biorrhiza (Biorhiza) pallida, the oak apple gall wasp, although in this case the wingless female will have emerged early from the generation that feed on root galls. Added elsewhere is another picture that shows the very short ovipositor of the wasp, tucked away under the rear end.

Robert Homan

petershirley's picture

Mystery insect

This is definitely a wingless agamic female Biohiza pallida. Found in the bark because these insects have to walk from the roots to the buds in order to lay their eggs. Affected buds turn into the familiar 'oak apples' in the spring and early summer. The wingless generation is female only, each oak apple contains either winged males or winged females. When they mate in late summer the females go down to the roots to lay their eggs. This wasp has a two year life cycle, so if oak apples appear every year on the same tree there are two different populations present.

Peter Shirley

dejayM's picture

Historical

I love the History section in iSpot - what magic, what camaraderie, what wisdom - where has it all gone?
Do you think it might be worth a Section somewhere called History - where selected posts are displayed in a Carousel or a monthly slot. Or is it waiting for me to do a Project called History Posts?
Now see http://www.diptera.info/forum/viewthread.php?thread_id=10523 (if any of you come back!)
Gorgeous
ðerek