Flea beetles : The three most common flea beetle species commonly found in the Pacific Northwest are the crucifer flea beetle (Phyllotreta cruciferae) on brassicas, the tuber flea beetle (Epitrix tuberis) on potato tubers and foliage, and the western potato flea beetle (E. subcrinata) on solanaceous crops. Overwintering flea beetle adults emerge in mid- to late spring, become more active when the days get warmer, and move into fields as their preferred host plants become available. 
Planting schedule. Flea beetle larvae emerge in mid- to late spring and adults emerge in mid-summer through fall: by planting earlier or later, you can avoid flea beetle larval feeding, adult emergence, and peak adult feeding activity.
Living mulches also provide habitat for ground-dwelling beneficial insects such as predatory ground beetles which can feed on the larval and adult stages of flea beetles. Although little research has been done to identify specific living mulches and ground covers that are effective in flea beetle suppression, in general, living mulches can consist of legumes such as clover and vetch. It is important to note that living mulches can compete with cash crops for nutrients, space, and water, sometimes reducing yield, and thus it may be best to plant living mulches in alleyways between crop beds. 
Sanitation. Sanitation practices such as mowing and tilling weeds (especially early in the season) and removing plant debris within cash crops can reduce flea beetle populations by minimizing food sources and overwintering habitat. Particularly troublesome weeds are volunteer host plants such as weedy mustards.
Mechanical and Physical: Floating row cover. Floating row covers are physical barriers placed over cash crops to exclude flea beetles. Install the floating row cover over the crop before flea beetles are in the area, and secure well on all sides.
Grow flowering plants such as anise, dill, chamomile, marigold, or clover around the host plants to enhance floral resources and encourage the native parasitic wasp and other generalist predators. For more information on using flowering plants to encourage beneficial insects, see the Pacific Northwest Extension publication Encouraging Beneficial Insects in Your Garden (PNW0550) and the U.S. Department of Agriculture publication Plants for Pollinators in Oregon.
. Entomopathogenic nematodes are soil-dwelling parasitic worms that kill insects. Many insects that have a life cycle in the soil, including flea beetles, are susceptible to biological control organisms. Entomopathogenic nematodes in the families Steinernematidae and Heterorhabditidae can attack the larval stage of flea beetles, thereby reducing the emerging population
Biological Pesticides: Fungal pathogens. Beauvaria bassiana is a fungus commonly found in many soils, and it causes a disease in insects known as white muscadine that has been shown to reduce flea beetle populations. When insects come into contact with B. bassiana fungal spores, either by sprayed droplets or exposure to a treated surface, the spores attach to the insect, germinate, and penetrate the insect’s body. The fungus releases toxins that liquefy the insides of the insect, creating a food source for the fungus and subsequently killing the insect. The B. bassiana strains GHA and ATCC 74040 are effective at controlling flea beetles, and some formulations are organically approved and can be purchased commercially. It is most effective to apply B. bassiana in the evenings because sunlight can kill these spores.
I know that this amount of information can be overwhelming, but it gives you multiple choices in controlling this pest.