1) SUMMARY

Flea beetles, primarily Epitrix spp., can be important pests of sugarbeets.  These pests feed on seedling beets at the time of emergence or even slightly before the emergence of the seedling through the soil.  Flea beetles are recognized sugarbeet pests in the Klamath Basin and in many cases must be controlled in order to establish a stand.  The production of potatoes in this area many contribute to the populations of flea beetles since the tuber flea beetle feeds on potatoes and can occasionally be a pest of potatoes.  Flea beetles are not a known pest in the other production regions but may be a component of the complex causing poor seedling establishment.  This is presently being researched, and no conclusions have been obtained yet.

Flea beetles overwinter as adults in crop residue and in soil cracks.  As the temperatures warm in the spring, they emerge and are voracious feeders.  This corresponds with the planting and emergence of beets in the Klamath Basin.  The flea beetles clip the seedlings as they emerge.  The adults deposit eggs in the soil and the resulting larvae feed in roots.  The larval damage is not known to cause any problems in sugarbeets.  There are two flea beetle generations per year.

 2) CURRENT PEST MANAGEMENT PRACTICES

Cultural Control:  No cultural controls are available for flea beetles.  Minimizing crop residue, fencerow vegetation, etc. would, in theory, remove the overwintering sites, but this really is not practical to the extent needed.  The beetles are quite mobile and can disperse over a wide area.  Maximizing sugar beet seedling growth so the seedlings will move through the susceptible stage is important.  Once the seedlings have two true leaves, the flea beetles do no significant damage.  Unfortunately, in the Klamath Basin early-season sugar beet growth is frequently limited by environmental conditions and is beyond control.

Host Plant Resistance:  None available.

Biological Control:  No research has been conducted in this area.

Chemical Controls:  Insecticidal controls are used for flea beetles management in the Klamath Basin.  Gaucho® (imidacloprid) seed treatment, Temik® granular (aldicarb) at planting, and Sevin XLR Plus® (carbaryl) are the most effective treatments.  Several other foliar treatments as well as Thimet® granular have been evaluated with poor to moderate results.

  3) REDUCED-RISK OPTIONS

  Seed treatments with low dosage of insectides.  The use of low dosage seed treatments (Gaucho®) could result in reduced foliar and soil treatments.

 4) CHALLENGES

Potential Impact of FQPA:  If fully enacted, the outcome of FQPA would result in only Gaucho® being available.  Since Gaucho® is a seed treatment, this would be a totally preventive program.  The present system utilizes both preventative and as-needed, foliar treatments.  This range of treatment strategies is a positive force in terms of IPM.

  There is a lack of understanding of flea beetle population dynamics, factors influencing flea beetle density, possible biological control, etc.

Prediction of fields with damaging flea beetle populations has been difficult.

 5) INNOVATIVE FEATURES IN REDUCED-RISK PROGRAM

  The use of low dosage seed treatments (Gaucho®) could result in reduced foliar and soil treatments.

 6) BARRIERS TO ADOPTION OF REDUCED-RISK METHODS

  Cost.  Sevin KLR® is less expensive and considered by growers to be comparable control.