Currently viewing the category: "Galls"

Subject: Black Oak Visitors
Location: Maumee, OH
September 18, 2013 9:21 am
The black oak next door is hosting two creatures that I am asking you to identify. One is probably some kind of wasp gall. It is a small white ball with bright red spots. The other is most likely a moth. Both are nestled on the back side of the leaf. The attached photos were taken on Sept. 17, 2013.
Signature: Jerry

Oak Gall might be Loxaulus maculipennis

Oak Gall might be Loxaulus maculipennis

Hi Jerry,
The gall might be caused by a Cynipid Wasp and it looks like a smaller version of the
Loxaulus maculipennis we found pictured on both the Oklahoma Biological Survey and the Henderson State University Plant Gall page.


Subject: Strange eggs on dead leaves
Location: Kansas City, MO
December 1, 2012 6:25 pm
Been seeing these little egg sac things on dead leaves all over. I am in Kansas City, MO. Any idea?
Signature: Celina

Oak Leaf Galls

Dear Celina,
These are not eggs.  They are Galls and they are produced by a tiny Gall Wasp.  They are produced as a larva feeds, and eventually an adult Gall Wasp will emerge from the gall.  The Galls in your photo are somewhat unusual in that they are on the top surface of the oak leaf.  We tend to see more Galls form on the underside of the leaves.  We will try to determine a little more specifically the identity of your Oak Leaf Galls.  We do not want to totally discount that these Galls might be produced by some other creature, like a mite or a fly.  See BugGuide for more information on Gall Wasps.

Oak Leaf Gall

”in-line branch” bug pod – don’t know how to describe
Location: Lancaster, Pennsylvania
November 20, 2011 3:09 pm
Any idea what sort of insect grows inside these ”pods” on these shrub branches? When I cut them open there is a 1/4 inch ”grub” in the center.
They make great toy spinning tops.
Thank you for your time and your help!
Signature: cfunck

Goldenrod Galls

Dear cfunck,
This is a sight our editorial staff is quite familiar with having grown up in eastern Ohio.  Interestingly, this is the first submission we have received of Goldenrod Galls despite having this online column for more than 12 years.  These Galls
are formed by the Goldenrod Gall Fly, Eurosta solidaginis.  You may read more about this insect on BugGuidewhere it is stated:  “Larvae form round galls on the stem of certain goldenrods, Solidago. They feed there, then pupate in early spring. Adults emerge April-May and mate near goldenrod.”  Galls are growths on plants that are often caused by insects including flies, wasps and moths, and sometimes by mites.  Galls are abnormal growths that generally do not harm the plant, and though they are usually produced by insects and other arthropods, they can also be cause by other sources.

Goldenrod Gall

Thank you so much for this information!
Kind regards,
Chris Funck


oak apple gall
Location: Tampa, Florida
May 1, 2011 10:51 am
Hey, just thought you might think this was a cool pic I took…
Signature: Melody

Interior of Oak Apple Gall

Hi Melody,
Thanks so much for contributing your photo of the interior of an Oak Apple Gall, revealing the larval wasp in the genus
Amphibolips inside.  Gall Wasps in the family Cynipidae are a fascinatingly diverse group that was studied in depth by Alfred Kinsey.  The Gall itself is a growth on a plant that may be produced by a variety of sources.  Gall Wasps produce growths on leaves, stems and roots though each species forms a distinctive Gall.  The larva then feeds on the tissue produced in the Gall.  It is currently accepted that the Galls do not harm the plant.  You can see other photos of Oak Apple Galls on BugGuide.

Insect egg?
Location: Arkansas
March 19, 2011 9:01 pm
Bugman–we were hiking in west/central Arkansas in the Ouachita mountains and found this round orange ball with red spots on a leaf on the ground. It was about 3/4 of an inch in diameter. It was mid-March in a mixed deciduous/pine forest. What is it?
Signature: Joyce

Oak Leaf Gall

Dear Joyce,
This is theoretically not an insect egg, but it was produced because of the laying of an insect egg.  This is a Gall.  Galls are growths produced on plants, usually because of an insect or mite, though fungus and other causes may produce gall-like structures.  This is probably the result of a Gall Wasp in the family Cynipidae.  The Gall Wasp lays an egg, and when the egg hatches, the larva releases an enzyme that causes the Gall to grow.  The Gall Wasp Larva then feeds on the tissue in the Gall.  Galls do not harm the plants.  Here is a similar photo on BugGuide, and one on Wikimedia.

What is this?
Location: Gwynn Oak, MD
March 17, 2011 9:01 am
I have 3 or 4 of these things in my juniper bush. I am not sure what it is and want to know if they are safe to have on the bush and at my front door.
Signature: M. Kelly

Cedar Apple Rust Gall on Juniper

Dear M. Kelly,
Abnormal Growths on plants are known as galls, and many are caused by insects and mites, though there are other additional causes for plants to produce galls.  We did a search for Galls on Juniper and we immediately discovered the Cedar Cedar Rust Gall on the University of Michigan Integrated Pest Management for Home Apple Growers web page.  You need to scroll down the page to get the information, which includes:  “Gymnosporangium juniperi-virginianae  Cedar-apple rust is a fungal disease that spends half of its life cycle infecting apple or crab apple trees, and the other half infecting Eastern Red Cedar (Juniperus virginiana) or other species of juniper (Juniperus sp.). This disease can cause damage to leaves and fruit of very susceptible apple varieties, but is only a minor problem on resistant or partially resistant trees.”  There is also a nice photo of the gall on FlickR.

Thank you very much for the information!!!!
I will cut them off and dispose of them and follow up and read the web pages you included in your response. Not that I like it, I can deal with a fungus better than bag worms or other insects.
I appreciate your quick response. 🙂
M Kelly