Aceria malherbae
bindweed gall mite
mite: (Acari: Eriophyidae)

Aceria malherbae
This photo is used purely for educational purposes. Click on the photo for their use policy. Photo from

Origin: Greece, France, and Italy, its native distributions include Central and Southern Europe and Northern Africa. (4)
Description: The adult Aceria malherbae mite is very small (microscopic).  They are a yellowish color and would remind one of a worm.  They are gall mites.  They are about .2 millimeters in length. (2)  The mites are slow moving therefore in order for good field bindweed control, they need human help to disperse. (1)
Life cycle:
over wintering state(s): During adult and nymph stages.  These mites live on the root buds under the soil in the winter. (3-5)
egg stage: The eggs are spherical and transparent.  They are deposited in the galls.  The galls are the swelling of the stems of the field bindweed that are produced when attacked by Aceria malherbae.  (3-5)
larval stage: Aceria malherbae has no larval stage because it is a mite and not an insect. (3)
pupil stage: Aceria malherbae mite has no pupil stage. (3)
nymph stage: There are two nymphal stages.  The nymphs are just like adults but only smaller versions and they lack external genitalia. (3)
adult stage: The adults are a mite that is yellow-white in color and their bodies are soft with no exoskeleton. The adults are active from May to November.  They are small and worm like.  They have a circular body with two pairs of legs found on the joined head and thorax (cephalothorax). (4-5)
Type of damage to host: The mite causes galls in the plant.  In a heavily damaged plant, the shoots are stunted in growth and they are misshapen.  They attack along the mid-vein of the plant and produces a "fuzzy" texture (2)  and galls also occur on the leaves, petioles, and stems. (4) The stages that they do the most damage is the adult and nymph stage.  The plant species that they attack is field bindweed (Convolvulus arvensi) and Calystegia ssp. (4-5)
Host impact (method/focus): Out in the wild, we are uncertain about the impact caused by Aceria malherbae.  In laboratory testing, the mite causes stunted growth and the plant doesn't produce flowers. (4)
Favorable/Unfavorable release habitats: Not known at this time.
How and where to collect, transport, and release: Collect the galls with the mites in them.  Stages that mites are able to be transferred are both adults and nymphs which are found in the galls.  Mites in galls will live as long as the galls are kept damp and cool. (4-5) To release the mite Aceria malherbae all you do is put the galls containing the mites on the ground right next to the field bindweed, so that they are touching. (3)
How to redistribute once established: To redistribute, take the galls from a well established site and follow the same procedure as releasing the mite from above. (3)
Where and how to purchase:  The availability of the Aceria malherbae is limited from the establishments in Texas. (5)
Remarks: The Aceria malherbae was first identified by the name A. convolvuli.  Mites produce galls on actively growing leaves and stem buds.  Leaf galls are noticed by the leaves that are distorted in figure and along the mid-vein where the mites eat.  The underside of the gall is roughened and will feel "fuzzy".  When the stem buds are attacked by the mites, they fail to grow properly and therefore grow in a close bunch of distorted and short leaves. (4)


(1) Michels, Dr. Jerry 9/16/97.  "Panhandle" Entomology [online - link no longer active]. 
(2) McClay, Alec 9-8-99.  Aceria malherbae Nuzzaci (Acari: Eriophyidae) [online - link no longer active].          

(3) Breitenfeldt, Todd, Personal interview, biology teacher, Whitehall Schools, Box 1109, Whitehall, MT 59759 (406) 287-3862. Sept. 1, 1999.

(4) Reese Norman, et., al., Ed., Biological Control of Rangeland Weeds in the Northwest United States, Manuscript/ Rough Draft.  1996 (5) Reese, Norman, et. al., Ed., Biological Control of Weeds in the West, Western Society of Weed Science, in cooperation with USDA, ARS, MT Dept. of Agriculture, and MT State University, Color World Printers, Bozeman, MT, Feb. 1996.

By: Tressa Carey      Published by: Tressa Carey    Updated By: Hans Jones, 02/05/2008.