Currently viewing the category: "Gall Wasps"

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:  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: 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.

Subject: eggs on roses leaves
Location: Japan
June 4, 2016 6:08 pm
I found these on the leaves of one of my roses in Japan.
Tried to google it, but couldn’t find them on the net….
It would be great to know !
Thank you!
Signature: Dasha

Spiny Rose Leaf Gall

Spiny Rose Leaf Gall

Dear Dasha,
These are not really eggs.  The are Galls, growths on plants that are usually caused by insects.  According to the University of Minnesota:  “Galls are abnormal plant growths caused by various organisms (insects, mites, nematodes, fungi, bacteria, and viruses). This publication will deal with galls caused by the feeding or egg- laying activity of insects and mites. Because of their unusual forms and colors, galls often cause homeowners to become concerned. However, galls seldom threaten plant health and their numbers are highly variable from season to season. For those reasons, control is generally not suggested. How are galls formed?  Galls are formed by insect/mite feeding or egg-laying activity. Either mechanical damage or salivary secretions (introduced by insects and/or mites) initiate increased production of normal plant growth hormones. These plant hormones cause localized plant growth that can result in increases in cell size (hypertrophy) and/or cell number (hyperplasia). The outcome is an abnormal plant structure called a gall.
Gall formation generally occurs during the accelerated growth period (late spring) of new leaves, shoots, flowers, etc. Mature plant tissues are usually unaffected by gall-inducing organisms. The gall-making organism develops inside the gall and the gall continues to grow as the insect/mite feeds and matures. Once gall formation is initiated, many galls will continue to form even if the insect dies. In addition, most galls are usually not noticed until they are fully formed and remain on plants for extended periods of time (more than a season).”  We believe your Galls are Spiny Rose Leaf Calls that are caused by the Gall Wasp,
Diplolepis polita, thanks to a matching image on  We verified the identification on BugGuide.  We will be postdating your wonderful submission to go live during our absence from the office next week.

Spiny Rose Leaf Gall

Spiny Rose Leaf Gall

Thank you Daniel for your quick and thorough response!
Wish you a lovely Sunday!

Winter Critters
December 30, 2009
I took a walk in the woods this month in western New York and found many little critters on top of the snow. I would appreciate any help you might be able to give in identifying. The trails are on a 600-acre wetland preserve and most of the pictures were taken in mixed woods of pine, hemlock, cherry, maple, oak, etc. that surround a very slow-moving marshy pond.
All of the pictures can be found on my blog (which links to bigger versions on Flickr):
There were some spiders, too… Can you help with them?
Thanks in advance for your help!
Jennifer Schlick
Wetland preserve, western New York State on Dec 22, 2009

Gall Wasp

Gall Wasp

Hi Jennifer,
While the creatures in your photographs are all similar in that they were discovered in the snow, taxonomically (and that is how we try to organize on our website) they are unrelated.  We are going to split them up and post them independently of one another.  We are most curious about the first image, which is obviously a Hymenopteran, but not an ant.  We did a web search of “wingless wasp in snow” and were led to a BugGuide page on Gall Wasps.  Interestingly, there was an individual found in Massachusetts also walking on the snow in January 2008.  It was identified as being in the family Cynipidae, but the species was not identified.  Gall Wasps are most difficult to identify to the species level.  The posting contained this comment from Richard Vernier:  “More accurately a so-called ‘agamous’ female. Just like palaearctic Biorrhiza pallida, this winter generation contains only females, who lay eggs inside winter buds of oak-trees, after having grown-up at the roots of the same host plant.
” has a link to a UTube video of a Gall Wasp walking on the snow in Japan.  We also recommend the Snow Critters web page.

Wow.  You’re my hero.  thanks a billion.  Now I’m going to have to write a blog post about the wonderful folks over at What’s that Bug!!!

Here’s my blog post:
Thanks again!