How to Manage Pests
UC Pest Management Guidelines
Scientific name: Chromatomyia (=Phytomyza) syngenesiae
(Reviewed 1/07, updated 6/09, pesticides updated 5/15)
In this Guideline:
Adults are small black to gray flies with yellow markings. Females puncture leaves to feed on plant sap and lay eggs within the leaf tissues. After 2 to 4 days eggs hatch and larvae feed between the upper and lower surface of the leaves, making distinctive winding, whitish tunnels or mines that are often the first clue that leafminers are present. Larvae emerge from the mines and pupate on the leaf surface or, more commonly, in cracks in the soil. Many generations occur each year and the entire life cycle can be completed in less than 3 weeks when the weather is warm.
The primary damage caused by the chrysanthemum leafminer is the mining of the leaf by the larvae. When infestations are severe, the plant's photosynthetic capacity is reduced and there is a reduction in crop yield.
Chrysanthemum leafminer is usually kept in control by naturally occurring parasites and does not require any additional control efforts. All precautions should be taken to ensure that the parasites are not killed by pesticide sprays applied for other pests. In cases of severe infestation, a treatment may be warranted.
Organically Acceptable Methods
UC IPM Pest Management Guidelines: Artichoke
Insects and Mites
M. A. Bari, Artichoke Research Foundation, Salinas
Acknowledgment for contributions to Insects and Mites:W. E. Chaney, UC Cooperative Extension, Monterey County
W. L. Schrader, UC Cooperative Extension, San Diego County
L. Handel and T. K. Shannon, Kleen Globe, Inc., Castroville, CA