How to Manage Pests
UC Pest Management Guidelines
Palestriped Flea Beetle
Scientific Name: Systena blanda
(Reviewed 1/09, updated 1/09, pesticides updated 4/16)
In this Guideline:
DESCRIPTION OF THE PEST
Flea beetle adults are small (about 0.12 inch long), shiny beetles with enlarged hind legs that allow them to jump like fleas. The palestriped flea beetle has a broad white stripe down each brown wing.
Adult flea beetles do most of the damage by feeding on the undersides of leaves, leaving small pits or irregularly shaped holes on the leaves. Large populations can kill or stunt seedlings. Older plants rarely suffer economic damage although their older leaves may be damaged. In the Imperial Valley, larvae feeding on roots have caused serious damage on occasion. This damage is easily confused with cavity spot symptoms.
Remove weeds along field margins and deeply disk plant residue in infested fields after harvest.
Organically Acceptable Methods
Cultural controls are acceptable for use on organically grown produce.
Monitoring and Treatment Decisions
Check newly emerged seedlings twice weekly for flea beetle damage until plants are well established. Relatively low populations can cause economic damage when plants are in the cotyledon or first-leaf stages. Treat if you find several damaged rows; spot treatment of outside rows or borders may be sufficient. Baits are not effective.
Once plants have several true leaves, they can tolerate several beetles per plant without damage. Older plants are even more tolerant. Insecticide treatment should rarely be required, but if it is, one application should suffice. However, chemical treatment may disrupt biological control of aphids and whiteflies.
UC IPM Pest Management Guidelines: Carrot
E. T. Natwick, UC Cooperative Extension, Imperial County
Acknowledgment for contributions to Insects:W. E. Chaney, UC Cooperative Extension, Monterey County