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Photo#303548
Woolly Oak Gall? - Macrodiplosis niveipila

Woolly Oak Gall? - Macrodiplosis niveipila
Willow Grove, Montgomery County, Pennsylvania, USA
July 2, 2009
Size: 1 cm or more
Is this the wooly oak gall? On the underside of an oak leaf.
It is similar to this. There are some references on that page, such as Callirhytis sp.
The inside of the gall was empty, except for these tiny eggs. I doubt it that this is the gall-maker.

Images of this individual: tag all
Woolly Oak Gall? - Macrodiplosis niveipila Woolly Oak Gall? - Macrodiplosis niveipila Woolly Oak Gall? - Macrodiplosis niveipila Woolly Oak Gall? - Macrodiplosis niveipila

Moved
Moved from Gall Wasps.

Questions
The gall shown in this photo was thin-walled and was just one continuous chamber, correct? Also, was there a slitlike opening on the upper side of the leaf?

 
One chamber
Yes, there is only one chamber, although slightly strangled in the middle; the wall seemed thicker than the leaf itself and velvety inside. I don't see a slit on the upper side of the leaf. See the photos I just added.

 
Slit
The new photos do show the slit I'm talking about--these galls are basically greatly distorted folds along the veins, and this crease is visible along the full length of the lower gall in the third photo. I'll put more info on the guide page, coming soon...

teach me?
the wasp or other critter laid eggs on a leaf then the gall grew around them..or in the leaf and it grew around them? do the eggs secrete a substance that makes a gall grow?

 
A big subject
I am trying to learn myself. As far as I know galls are made by "genetic engineering". The gall maker induces the growth of the gall by hijacking the genetic machinery of the host and forcing it to grow a sort of tumor. It is not uncontrolled growth like cancer but it is well organized and it serves the gall maker's purpose, supplying food and housing to it or its brood. There are so many kinds of galls and gall makers that it is a huge subject.
Wikipedia has an article on galls and others on gall wasps, gall flies, etc. You may find some answers there.

 
thanks..i was watching them g
thanks..i was watching them grow on the wild roses..when they start they are bright pink, its actually very interesting..

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