Currently viewing the category: "Galls"

Subject:  Unknown Moth Chrysalis?
Geographic location of the bug:  Northern VA
Date: 05/18/2019
Time: 03:06 PM EDT
Your letter to the bugman:  Hello, I was walking today (May 18) and found this unusual growth on a small tree sapling off of the neighborhood trail. I’ve searched but have only found one image even close and it was a silk moth chrysalis.
How you want your letter signed:  N. Celata

Oak Apple Gall

Dear N. Celata,
Your sapling appears to be a young Oak and this is a Gall, a growth that appears on plants and is often caused by an insect.  Oaks are hosts to many different Gall Wasps that produce Galls.  Based on images posted to Discover Life, we believe this is an Oak Apple Gall,
Amphibolips confluenta.

Subject:  Eggs on oak leaf
Geographic location of the bug:  Maine
Date: 12/07/2018
Time: 09:07 AM EDT
Your letter to the bugman:  I found this egg mass on an oak leaf in my backyard in September. There are just six eggs laid together on the leaf. I believe they are some kind of insect eggs but I do not know what!
How you want your letter signed:  Hannah

Oak Galls

Dear Hannah,
These are Galls, and they are theoretically not eggs.  Galls are growths on plants (leaves, stems, roots, etc.) that are caused by a variety of reasons, including insects.  Gall Wasps on oaks are quite common and quite diverse.  The Gall is a growth caused by the Wasp larva that then provides a food source for the growing larva.  So the larva does not eat the plant directly, but it does feed on the growth that its presence has caused.  We will attempt to provide you with a less general identification.

Subject:  Oak Gall
Geographic location of the bug:  Mount Washington, Los Angeles, California
Date: 11/25/2018
Time: 4:30 PM EDT
While we are waiting to clear up our technical difficulties receiving images, Daniel is spending some extra time in the yard.  He noticed this Oak Gall several days ago.  It is growing on a California Live Oak tree Daniel started from an acorn in 2000 that is now over 20 feet high and it has begun producing acorns.  We have always been intrigued that Alfred Kinsey began his career as an entomologist who studied Cynipid Gall Wasps, and that he collected well over a million specimens, and that he transferred that obsession to the data collecting methods that eventually produced the Kinsey studies on human sexuality.

Oak Gall


Subject:  What is this egg sack from?
Geographic location of the bug:  Decatur, IN
Date: 11/27/2017
Time: 06:32 AM EDT
My grandson and I found this at the bus stop this morning and would like to know what it is and what we should do with it.
How you want your letter signed:  Adventurous G-ma

Oak Leaf Gall

Dear Adventurous G-ma,
This is not an egg sack.  It is an Oak Apple Gall, and it was formed when a Gall Wasp lays an egg on an oak leaf, causing a growth that serves as food for the developing Gall Wasp larva.  Galls do not harm the tree.  Similar images can be found on Buckeye Yard & Garden Online and Missouri Botanical Garden.   Interestingly, Alfred Kinsey, the famous entomologist, studied Gall Wasps before he turned his scientific methods to humans which resulted in the famous (and infamous) Kinsey Reports.  Kinsey founded the Institute for Sex Research at Indiana University and his reports resulted in the publication of the groundbreaking “Sexual Behavior in the Human Male” in 1948 and “Sexual Behavior in the Human Female” in 1953.  They were best selling books that changed the way America and the world think about human sexual behavior.

So…are there wasp  larvae in it or is it empty?

We suspect it is empty.

Subject:  Is this an insect sac?
Geographic location of the bug:  Southeast MO
Date: 10/07/2017
Time: 08:10 PM EDT
Found Oct 7, 2017 bear Lampe, MO.
How you want your letter signed:  PJ

Oak Gall

Dear PJ,
This is a Oak Gall, probably caused by a Gall Wasp in the family Cynipidae.  According to Henderson State University:  “Galls are abnormal, vegetative growths that are usually formed as a response by plants to the action of fungus, mites, or insects such as wasps, aphids, and true bugs. Galls can be formed in the leaves, petioles (stem) of leaves, twigs, buds, or on the roots.”  More information on Galls can be found on Arborilogical.  Your Gall looks similar, but distinctly different than the Eastern Speckled Oak Gall pictured on ISA Texas.

Subject: Strange Egg Sac
Location: Effingham, IL
September 10, 2016 7:19 pm
I found this strange (what I believe is an) egg sac on a fallen leaf in Effingham, IL. I know you identify insects. Are you able to identify their eggs as well? Assuming this is an insect egg… Thanks!
Signature: Best, Jennifer

Spiny Oak Leaf Gall

Hedgehog Gall

Dear Jennifer,
This is a Gall, a growth appearing on a plant that might be caused by an insect, other arthropod or even an injury.  We found a very similar image on the Blue Jay Barrens blog, but the only information is:  “The oak leaves are developing some wonderful galls. I’m not sure how large these pea sized growths will eventually become.”  We found an image on Field Biology in Southeastern Ohio with the information:  “Spiny Hedgehog Galls. The yellow gum drop covered in red hairs makes this wasp
Acraspis erinacei. ”  Another similar image is on the Springfield Plateau blog and the name Hedgehog Gall is used.  Hedgehog Gall is also the name used on BugGuide and according to BugGuide:  “Forms galls on white oak (Quercus alba). The sexual generation forms galls on the buds, and the agamic generation forms the distinctive ‘hedgehog’ galls (ellipsoid, up to 13 mm in diameter, covered with red hairs, with 3-5 larval cells inside) on leaves. Females emerge from the leaf galls in the fall (October-December) and crawl to the buds to oviposit. The resulting gall is a thin-walled blister on the inner face of a bud scale, appearing as the buds start to open in the spring.”

Hi Daniel,
Thank you so much for sharing!  How incredibly interesting.  Nature is amazing.