Cystiphora schmidti
<<back to rush skeletonweed
Common Name
Rush skeletonweed gall midge
Weed Impacted
Larvae feed on the leaf and stem tissues of rush skeletonweed, reducing the nutrients available for plant growth and maintenance. Plant tissues are either damaged or destroyed, causing yellowing, wilting, or death of those tissues. Infested plants may have reduced biomass, flower production, and seed viability. Rosettes may also be killed.
Insect Description
Adults are small (0.8 to 1.6 mm or approximately 1/32 to 1/16 inch long), somewhat nondescript light or medium brown flies. Larvae are pale pink or orange, 1 to 2.5 mm (approximately 1/32 to 3/32 inch long), and somewhat flattened.
Life Cycle
Cystiphora schmidti complete four or five generations per year. Adults are found in the field from April to October, but individual flies live for only a few days after emergence. Eggs are laid in rosette leaves by first-generation females and stems by subsequently emerging females. Larvae feed on plant tissue around the site where they hatched, causing the formation of galls* at the site of attack. Mature larvae pupate either within the galls or occasionally in the soil litter under host plants.
* galls are an abnormal swelling or deformation of plant tissue caused by insects, mites, microorganisms or injury
Field Identification
Presence of C. schmidti in the field can be indicated by galls formed on infested rush skeletonweed leaves and stems. Leaf galls are spherical and only marginally raised from the leaf surface compared to stem galls which are stretched and generally more elevated. Affected plant tissue is typically swollen and yellowish or maroon-colored.
Availability
This agent is readily available in Washington, Idaho, and California. Galled stems are harvested from July through September. To inquire about availability and to request this biocontrol agent, please download, complete and submit this form.
Comments
Parasitic wasps have been reported to diminish the impacts of C. schmidti at some sites in Washington, and have severely reduced agent populations in California. Cystiphora schmidti does best in warm, dry areas with well-drained soil.
Using the Agent: Integrated Weed Management (IWM)
Cystiphora schmidti may be used in combination with the rush skeletonweed gall mite (Eriophyes chondrillae) and/or the skeletonweed rust fungus (Puccinia chondrillina). Biocontrol agents should only be released when rush skeletonweed infestations are large and immediate eradication is not the primary objective.
Individual plants and smaller, satellite populations may either be hand-pulled, dug, or sprayed. Herbicides should not be applied where biocontrol agents have been released. Consult with your county weed office, Extension office or an IWM practitioner to determine which herbicide treatments are safe and appropriate.
Any management of rush skeletonweed should involve revegetation with native or other desirable plants. Competition between plants stresses weeds and can allow for more effective treatment. To learn more about revegetation and IWM, click here.
References
Coombs, E. M., J. K. Clark, G. L. Piper, and A. F. Cofrancesco, Jr. 2004. Biological Control of Invasive Plants in the United States. Western Society of Weed Science, Oregon State Univ. Press, Corvallis.
McCaffery, J. P., G. L. Piper, R. L. Callihan, and E. M. Coombs. 1996. Collection and redistribution of biological control agents of rush skeletonweed. University of Idaho Extension Publications. Bulletin 782.
Photo Credits
Cystiphora schmidti adult - Gary L. Piper, Washington State University, bugwood.org (insectimages.org), http://www.insectimages.org/images/768x512/0022090.jpg
Cystiphora schmidti galls - Gary L. Piper, Washington State University, bugwood.org (insectimages.org), http://www.insectimages.org/images/768x512/0022091.jpg
Secondary content using h2 tag. Column 2
Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.
Heading using the h3tag
Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.