How to Manage Pests
UC Pest Management Guidelines
The potato flea beetle is a small (0.065 inch), shiny black beetle. The threespotted flea beetle is two to three times larger and has an orange-colored thorax on which are three prominent dark spots. The palestriped flea beetle is about twice as large as the potato flea beetle. It is dark brown and has a longitudinal creamy white stripe on each wing cover. The tuber flea beetle is about the same size as the potato flea beetle and is also black and somewhat shiny, but has even rows of small indentations on the wing covers. All of the flea beetles have enlarged hind legs and jump vigorously when disturbed, thus the name flea beetle.
Flea beetle damage is generally a concern only during the cotyledon and early leaf development stages. Damage is caused by adults and consists of numerous small rounded or irregular holes eaten in leaves so that leaves appear to have been peppered with small shot. In young plants this feeding damage can be very serious and result in plant death, thus reducing stands. In addition to adult damage, larvae of the palestriped flea beetle feeds on roots of young plants as well as on germinating seeds.
Keep fields weed-free, particularly free of field bindweed and mustard, which are preferred hosts of flea beetles. Replant heavily damaged fields. No economic thresholds are available, but consider treatments, especially on young plants, if damage reaches a moderate level. Once plants are well established, flea beetles rarely cause sufficient foliar damage to justify treatment.
|The following materials are listed in the order of usefulness in an IPM program, taking into account efficacy and impact on natural enemies and honey bees as well as the environmental impact. Not all registered pesticides are listed. Always read the label of the product being used.|
|(Lannate) LV||0.75–3 pt||48||see comments|
|(Lannate) SP||0.25–1 lb||48||see comments|
|MODE OF ACTION GROUP NUMBER1: 1A|
|COMMENTS: Preharvest interval is 21 days for roots, 30 days for tops.|
|(Sevin) XLR Plus||1–1.5 qt||12||28–roots and forage|
|MODE OF ACTION GROUP NUMBER1: 1A|
|+||Restricted entry interval (R.E.I.) is the number of hours (unless otherwise noted) from treatment until the treated area can be safely entered without protective clothing. Preharvest interval (P.H.I.) is the number of days from treatment to harvest. In some cases the REI exceeds the PHI. The longer of two intervals is the minimum time that must elapse before harvest.|
|*||Permit required from county agricultural commissioner for purchase or use.|
|1||Rotate chemicals with a different mode-of-action Group number, and do not use products with the same mode-of-action Group number more than twice per season to help prevent the development of resistance. For example, the organophosphates have a Group number of 1B; chemicals with a 1B Group number should be alternated with chemicals that have a Group number other than 1B. Mode of action Group numbers are assigned by IRAC (Insecticide Resistance Action Committee). For more information, see www.irac-online.org.|
UC IPM Pest Management Guidelines:
UC ANR Publication 3469
E.T. Natwick, UC Cooperative Extension Imperial County
Acknowledgement for contributions to Insects and Mites:
C. G. Summers, Entomology, Kearney Agricultural Center, Parlier
D. R. Haviland, UC IPM Program, Kern County
L. D. Godfrey, Entomology, UC Davis