Adult Chrysanthemum leafminers (Chromatomyia syngenesiae) are small, black to gray flies with yellow markings. The females puncture leaves to feed on plant sap and lay eggs within the leaf tissues. The larval stage lives in and nourishes itself from the plants leaf tissue.
Punctures caused by females during the feeding and oviposition processes can result in a stippled appearance on foliage. However, the major form of damage is the mining of leaves by larvae, which results in the destruction of leaf mesophyll. The mine becomes noticeable about three to four days after oviposition and becomes larger in size as the larva matures. Both leaf mining and stippling can greatly depress the level of photosynthesis in the plant. When in outbreak proportions, it may severely disrupt photosynthesis in the plant leaves eventually leading to dry-out, defoliation and a reduction in crop yield. Wounding of the foliage also allows entry of bacterial and fungal diseases.
There are specific natural enemies for different species of leaf miners.
For more information contact your local BioBee field agent.