Currently viewing the category: "Galls"

Hi – I wondered if you could identify the above images? The first one was on an elm tree – the whole tree was coveredin them. The second one (Oak ‘eggs’) was on the leaf until it dropped off in the autumn – what happened then I don’t know. They started out bright red but by autumn were a very pale pink. Many thanks!
Jo

Hi Jo,
Both of your photos illustrate Galls, growths that occur on various parts of plants that are usually caused by an insect or mite. Wasps, Moths, Aphids and Flies can all produce Galls. According to the University of Kentucky College of Agriculture website: “Galls are irregular plant growths which are stimulated by the reaction between plant hormones and powerful growth regulating chemicals produced by some insects or mites. Galls may occur on leaves, bark, flowers, buds, acorns, or roots. Leaf and twig galls are most noticeable. The inhabitant gains its nutrients from the inner gall tissue. Galls also provide some protection from natural enemies and insecticide sprays. Important details of the life cycles of many gall-makers are not known so specific recommendations to time control measures most effectively are not available.” Galls are not harmful to the plant. Regarding your images, we are not entirely conviced that the tree you indicate is an elm is really an elm. Also of interest with the color change in the Oak Galls is this citation from Lutz’ Field Book of Insects: “Of the Galls caused by insects, Oak Galls have been used in dyeing, tanning, and the manufacture of ink.”

Hi Daniel – thank you very much for your reply. I thought they may be galls but wasn’t sure. The tree was identified by a wildlife trust (I work for them so quite a few people saw the leaves and said they were elm). However no one was sure what the ‘lumps’ were. Have a good Christmas Best wishes
Jo

Lovely red stranger on oak leaves
Can you identify these red beauties attached to the base of some of the oak leaves in our backyard in Pleasant Hill, California? I included a picture of the oak leaves to assist you in identifying the type of oak – I’m not sure what type it is. Thank you!
Mabel Neys
Pleasant Hill, California

Hi Mabel,
We have been scouring the web for about an hour trying to properly identify your Oak Gall, probably to the chagrin of our other readers with questions sitting in our “in box”. Sadly, we will have to leave this identification at Unknown Oak Gall, probably one of the Gall Wasps in the family Cynipidae, and possibly in the genus Andricus based on the closest image we could find on BugGuide, Andricus fullawayi. We decided to give it one more try and located Andricus crystallinus, the Crystalline Gall Wasp. Looks like a perfect match. Galls do not harm the oak trees.

What is it?
Mr. Bug Man,
Very cool website. Hope you can help. We have some Sumac trees in our backyard and some of them have these ‘sacks’ on them. They are attached to a leaf and seem to be feeding off of it. They are seemingly air tight, when you squeeze gently they are like a miniature air pillow. When taken apart there is a small cotton ball inside that is very air born and there are what look like seeds or eggs, yellowish in color, many of them. The sacks are various sizes and some are turning red like an apple would. Sure would appreciate your thoughts. Thank you,
Doug Cornelius
Deansboro, NY

Hi Doug,
These are Sumac Galls. According to BugGuide, the galls contain Aphid Colonies.

Eggs or Gall?
Thank you very much for taking the time to create a site like What’s That Bug. My wife and I check it each day to see what new creatures have been identified. My question for you is, are the red objects in this picture insect eggs or just gall of some kind? The picture was taken in June at Burdette Park in Evansville, IN. I appreciate any help you can offer since I know you are very busy. Thank you again for all your time. Sincerly,
Sean and Emily Kemp

Hi Sean and Emily
Our old edition of Lutz’s Field Book Of Insects identifies these green or red galls on grape as Cecidomyia viticola. The insect that produces the gall is a midge. Outdoor Decor has some images.

Egg?
I looked through your egg photos and saw nothing that looked like my discovery. I know you are swamped so I’ll be patient. I found this "egg" on an oak (possibly Chestnut) leaf in East Central Indiana on July 25, 2007. The colors are beautiful and staturated with the little spikes surrounding the sphere. Hoping for a finding. Thank you,
Christie Coffey

Hi Christie,
This is not an egg but rather some type of Gall. We do not know enough about botany to be able to identify what tree your Gall is on, but that would be a great assistance. It is not the usual oak leaf we can identify, but there are many different species of oaks. Just assuming it is an oak, our Field Book of Insects written by Lutz and revised in 1948 states: “Oak. — More than three hundred different galls have been listed.” The University of Kentucky department of Entomology website states on its Common Oak Galls page: “Galls are irregular plant growths which are stimulated by the reaction between plant hormones and powerful growth regulating chemicals produced by some insects or mites. Galls may occur on leaves, bark, flowers, buds, acorns, or roots. Leaf and twig galls are most noticeable. The inhabitant gains its nutrients from the inner gall tissue. Galls also provide some protection from natural enemies and insecticide sprays. Important details of the life cycles of many gall-makers are not known so specific recommendations to time control measures most effectively are not available. ” Interestingly, The Kinsey Institute for Research in Sex, Gender and Reproduction, which is celebrating its 60th Anniversary this year, is in Indiana. The Institute is named for Alfred Kinsey, who shocked the world when his best seller, Sexual Behavior in the Human Male was published in 1948. Kinsey’s attention to detail regarding research can be traced to his earlier, though far less provocative, studies on Gall Wasps. We would like to believe that your gall has been produced by one of the Gall Wasps in the family Cynipidae that so fascinated Alfred Kinsey. We cannot find an exact match to your Gall on BugGuide.

big fuzzy ball
Is this a cocoon? It is growing all over the oak trees in my yard, and the trees are dying. Help! Thanks,
Lynn

Hi Lynn,
Today we vowed not to do any work that needed to get done until we posted two interesting letters. Your letter officially fulfills our vow. This is a Wool Sower Gall which is produced by a tiny wasp, Callirhytis seminator. Galls are growths on various parts of plants, usually caused by a Gall Wasp or a type of mite. There are many species of Gall Wasps, and each has a specific host plant.The Wool Sower Gall uses the oak as a host. If your trees are dying, it is not because of the Wool Sower Gall as they have no negative impact on the trees.