Currently viewing the category: "Galls"

Galls on Artemesia tridentata
March 13, 2010
Here is a photo of some different galls then I sent before. These are more common and are less rounded and in multiples joined together. I’m not sure if its a fly, beetle or mite. One guy said those other galls might be cecidomyiid fly. Both are on Artemesia tridentata.
Ernie
Okanogan, Wash.

Galls on Artemesia

Hi again Ernie,
Thanks for sending in more photos of Galls.  Perhaps an expert in Galls will be able to do a conclusive identification.

Galls on Artemesia

SAGEBRUSH GALL
March 9, 2010
FOUND THIS INTERESTING GALL ON SAGEBRUSH (ARTEMESIA TRIDENTATA) IS THIS THE WOOL SOWER CALLIRHYTIS SEMINATOR OR RHOPALOMYIA?
ERNIE
OKANOGAN, WASH.

Unknown Gall on Sage

Hi Ernie,
Galls, unusual growths on plants, are often caused by insects, but there might be other reasons that the plant tissue becomes distorted and produces the odd growths.  There is a nice online piece on Gall Making Insects by John A. Byers that has good information.  This is neither a Wool Sower Gall and we are not certain if this growth on sage is caused by a Midge in the genus Rhopalomyia without doing additional research.  We did find a paper online that was published by the Journal of the Kansas Entomological Society that mentions, but doesn’t picture, a Fruit Fly, Eutreta diana, that is called a Sage Stem Galling Fly.  We found the fly pictured on the Diptera Site, but again, a photo of the actual Gall produced by the fly has eluded us.

Gall or nest?
August 3, 2009
Hi guys!
I absolutely love your site, and tell all my friends about it! I found a very alien object clinging to a creosote bush behind my house, in Tucson AZ. It is a leafy sphere, about the size of a quarter. The leaves (which don’t look anything like those the creosote leaves) are arranged in whirls, like a grassy daisy, and there is a tiny hole in the center of each. Coming out of each hole are discarded exoskeletons, like those of the grain moth larvae you find in boxes of rice and pancake mix. They are probably only 4 or 5mm long. There is also a bit of silk strewn around the whole thing, which gives it a dewy, sticky look, but I haven’t touched it because I don’t want to be impregnated by some alien insectoid race. What kind of bug could construct such a crazy looking (and beautiful) nest? Or is it a gall of some sort? I am so very curious…
Thanks for your help!
Emily Rush
Tucson, Arizona, USA

Creosote Gall

Creosote Gall

Creosote gall
August 3, 2009
Hi!
Me again. After writing to you, I decided to google “creosote gall”. Don’t know why I didn’t do that first, I guess I was just excited to send you a pic of something you might not have seen before. Apparently my mystery alien sphere IS a gall, caused by, wonder of wonders, a creosote gall midge! I couldn’t find a picture of one though. Any help in this area?
Thanks again!
Emily Rush
Tucson, Arizona, USA

Hi Emily,
Thanks for sending us your photo of a Creosote Gall and doing the subsequent research.  BugGuide has images of the Creosote Gall filed under the species Asphondylia auripila with the information:  “Larvae form galls in creosote bush (Larrea tridentata),”
but if you go to the genus Asphondylia and browse, you will see some images of related Midges that probably look very similar to the Creosote Gall Midge. The only species on BugGuide with images of adults is Asphondylia solidanginis. Species in the same genus often have visual similarities and an expert is required to differentiate one from another.  Unlike the Oak Gall we just posted which was formed by a small wasp, the Creosote Gall is formed by a Midge that is in the order Diptera and is classified with the flies.  The Creosote Gall is a deformation of the plant with the leaves and stems stunted to form the Gall.  If you follow the taxonomy on BugGuide back to the Family Cecidomyiidae, you start to get a bit more information, including:  “Minute, delicate flies with long legs and usually relatively long antennae, and with reduced wing venation” and “more than 1,200 species in 170 genera in North America.” There are images of many different species on the Cicidomyiidae page of the Forestry Images website.  Some of the members of the family include the Skeletonweed Gall Midge and the St. John’s Wart Midge.  Those should give you some idea of what the Creosote Gall Midge looks like.  Again, thanks for sending us your photo.

Thanks Daniel!
I hope I can catch a midge in action. By the way, the root borer you posted is a Palo Verde beetle (Derobrachus geminatus). We have lot’s of them in Tucson- they’re HUGE, and they’re really active right now, during the monsoon. I like their fancy spiked collars! Here’s another!
Emily

Insect egg ball
July 31, 2009
Hi,
I keep finding these egg balls under an oak tree in my yard. Can you tell me what comes out of these? (The second picture shows their exits.) The wall material is paper thin and very brittle. They are about the size of a golf ball, beige, and bumpy.
Thank you.
Todd Shinn
Salisbury, NC

Oak Gall

Oak Gall

Hi Todd,
This is the Gall or Oak Apple formed by some species of Gall Wasp, a tiny wasp in the family Cynipidae.  The larval Gall Wasp creates the Gall as part of its growth process and the Galls do not harm the trees.
There are numerous species and according to BugGuide: Many different cynipid wasps form large, spherical galls on oak leaves, some of which are called “oak apples.” As with most galls, ID requires knowing the species of oak. It is also critical to look at the internal structure:  Even then, there are some very similar ones, and it may be necessary to examine the adult wasp that emerges.”  A British Website has a photo that matches your Gall, and it is identified as Biorhiza pallida, but we believe your new world species is not the same. According to BugGuide there are  “Over 750 species in North America in 49 genera” and “Small to minute, usually black, with characteristic shape: the abdomen is oval and somewhat compressed and shiny, the second tergum covers a good part of the abdomen. Each species makes a characteristic gall on a specific part of the plant. Many make galls on oaks. Most have a complex life cycle with a parthenogenetic generation and a sexual one. Each generation makes galls of a different appearance and on different parts of the plant. The recognized expert in this family is Charles Kinsey who died about 50 years ago after achieving worldwide fame for his studies of male and female sexuality.

I found cocoon-like brown hard masses on the front side of a leaf.What are they???
Wed, Oct 8, 2008 at 6:13 PM
I was sweeping off the porch at the campground that I stayed at during the summer/fall.We had a big wind storm come thru and there were a bunch of leaves on the porch.On a lot of the leaves,I noticed these little hard brown cocoon-like circles on the front side of a leaf.I was thinking that cocoons were laid on the under part of the leaf,and that they were soft to touch,but these are hard and round.So I decided to cut one open and inside are these tiny red-orange color worm-like things inside.They moved a little bit,so I just thought that they were a worm of some kind.I’ve looked all over the internet and came up with nothing.Finally I posted my question and someone told me to contact you.I have pictures of the “cocoons” and the “worms” inside.The worms are very small and hard to see on the picture.Please help me identify w hat I’ve found!
Curious Nature Lover
Shreve,Ohio

Oak Leaf Galls

Oak Leaf Galls

Dear Curious,
Galls are growths on plants that may be caused by insects, mites, bacteria or fungus.  The Galls may occur on the leaves, stems, roots or flowers of the plants.  Most often, the Galls are plant specific.  We located a drawing in a very old copy of a text by Frank E. Lutz that we own.  The drawing is of a Oak Leaf Gall known as Dryophanta polita.  Since the text is a field guide, there was no additional information beyond the identification.  When we tried a web search of that name, be were led to several online texts that we could not access entirely.  One such text is Insects Affecting Park and Woodland Trees and the google teaser is “Oak leaf bullet gall Dryophanta polita Bass. A small, globular gall occurs in
numbers in August … ”  Another reference led to the common name Polished Oak Gall.  At this point, we can only speculate that Dryophanta polita is a Gall Wasp in the family Cynipidae, but curiously, it is not listed in BugGuide’s taxonomy for the family.  Another interesting side note is that Alfred Kinsey, most widely known for his studies of human sexuality and his best selling books in the 1950s, was first and foremost an entomologist who specialized in Gall Wasps.

Dissected Oak Leaf Galls

Dissected Oak Leaf Galls

???eggs on bur oak leaf?????
HI,
I just took a photo of these bug eggs???? on the leaves of our bur oak tree today (Sept 22, 2008) . The eggs are hard (so my husband say’s I couldn’t get up the nerve to touch them). So it’s the beginning of fall here in Iowa. I was wondering if you could identify the egg for us. Our son who’s 4 spotted them on the tree. There are only a few leaves with the clusters. After trying to identify these in a few books and the help of your web site our 4 year old said why don’t you ask that cool web site we go to….so here I am asking for help.
Thanks so much for your time.
The Sims Family
Des Moines, Iowa

Oak Leaf Gall

Oak Leaf Gall

Dear Sims Family,
Though they might look like eggs, they are actually Galls.  Galls are growths on plants caused by insects, mites or other creatures.  We believe your Galls are Amphibolips coelebs and they are caused by a tiny Gall Wasp.  We identified them thanks to a wonderful old research book written by Frank E. Lutz, but we couldn’t find an image online.  Galls don’t generally cause the plants any harm.  In the case of the Gall Wasps, the growth creates a food source for the developing larva.