Manzanita Leaf Gall Aphid

Fold Gall Aphid

Aphididae

Tamalia

Arctostaphylos canescens

California

Oregon

Arctostaphylos glandulosa

Arctostaphylos insularis

Arctostaphylos manzanita

Arctostaphylos patula

Arizona

Colorado

Montana

Nevada

New Mexico

Utah

Washington

Arctostaphylos pumila

Arctostaphylos pungens

Texas

Arctostaphylos uva-ursi

Alaska

Connecticut

Delaware

Idaho

Illinois

Indiana

Iowa

Maine

Maryland

Massachusetts

Michigan

Minnesota

New Hampshire

New Jersey

New York

North Dakota

Ohio

Pennsylvania

Rhode Island

South Dakota

Vermont

Virginia

West Virginia

Wisconsin

Wyoming

Alberta

British Columbia

Manitoba

New Brunswick

Newfoundland and Labrador

Northwest Territories

Nova Scotia

Nunavut

Ontario

Prince Edward Island

Quebec

Saskatchewan

Yukon Territory

Saint Pierre and Miquelon

Arctostaphylos viridissima

Arctostaphylos viscida

Tamalia coweni

Fold-Gall Aphid (Tamalia coweni)

This aphid induces two kinds of galls: one, a common and widespread fold gall along the margins or midribs of leaves, occurring on many species of glabrous-leaved manzanitas; and the second, an uncommon convoluted swelling or baglike structure on the inflorescences of manzanitas. 

[UPDATE: Please read Gallformers ID Notes above for a 2023 taxon split that narrows the host list for this gall.]





Plant Galls of the Western United States

CAUTION: Taxon split. [A 2023 paper by Miller et al.](https://www.researchgate.net/publication/369567785_Three_new_species_of_Tamalia_Hemiptera_Aphididae_Tamaliinae_associated_with_leaf_galls_on_Arbutus_Arctostaphylos_and_Comarostaphylis_in_North_America) says T. glaucensis is "the only Tamalia aphid known to induce galls on A. glauca." See https://www.gallformers.org/gall/4937. In addition, galls on A. pringlei can be caused by either of two Tamalia species, so best ID is "Tamalia."  

Separately, here are some tips for distinguishing Tamalia aphid galls and Exobasidium fungus galls on manzanita leaves. The two galls are surprisingly similar in appearance. Generally, however: 
. Tamalia galls, like most insect galls, create enclosures.
. Tamalia galls usually occur on the leaf edge or along the leaf midrib.
. Tamalia galls are usually elongated.  
. Exobasidium galls on manzanita leaves (EGAML) are often convex/concave blisters [E. arctostaphyli]; there is also an undescribed Exobasidium that turns the entire shoot tip red. Photographing both sides of the leaf will often show a smoothly concave area on one side. 
. The red of EGAML is sometimes shiny, and the color often occurs on parts of the leaf that are not distorted.

Finally, additional information and a list of known hosts for Tamalia coweni can be found on [InfluentialPoints](https://influentialpoints.com/Gallery/Tamalia_coweni_manzanita_leafgall_aphid.htm).

Gallformers ID Notes