Eriophyes chondrillae
Skeleton Gall Mite

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Origin: Italy (1,2)

Description: Eriophyes chondrillae is a skeleton weed gall mite.  These mites go through about 3 stages of their life.  (1-3)

Egg: They lay eggs, about 0.04 millimeters in size that are most colorless with a little orange, and are laid in the gall.  They can lay a total of 60 to 100 eggs.  The plant known as rushskelton weed is attacked.  (1,2)

Nymphal: Nymphal development can be completed in 10 days during the summer on the leaves. (1,2)

Nymphal Stage 1:They look a pale yellow-orange.  They are about 0.08 to 0.1 millimeters long in this stage. (1,2)

Nymphal Stage 2: In this stage they start to look humped back, have 4 legs, and are about .1 to .17 millimeters long. (1,2)

Adult: When the plant stops producing nutrient supplies then the gall starts to dry.  The mites begin to transfer to new buds on the same plant or can move to other plants close by.  The males end up to be about 0.16- 0.18 millimeters long.  The females end up to be about 0.19- 0.26 millimeters long.  They both have soft bodies, pale yellow orange in color, and have two pairs of legs. (1-3)

Data: This mite is used as a biological control.  They are used to control rush skeletonweed of Canada.


(1)  Rees, 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.

(2)  Rees, Norman, et., al., Ed., Biological Control of Rangeland Weeds in the Northwest United States, Manuscript/ Rough Draft. 1996.

(3)  Breitenfeldt, Todd, Personal Interview, Biology Teacher, Whitehall Schools, Box 1109, Whitehall, MT 59759,,  (406) 287-3862. 

By: Kyle Clark        1/14/02 HOME  Back to Biological Control