Description of the Pest
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.
Damage
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.
Management
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.
| Common name | Amount per acre | REI‡ | PHI‡ | |
|---|---|---|---|---|
| (Example trade name) | (hours) | (days) | ||
| Not all registered pesticides are listed. The following are ranked with the pesticides having the greatest IPM value listed first—the most effective and least harmful to natural enemies, honey bees, and the environment are at the top of the table. When choosing a pesticide, consider information relating to air and water quality, resistance management, and the pesticide's properties and application timing. Always read the label of the product being used. | ||||
| A. | METHOMYL* | |||
| (Lannate LV) | 3/4– 3 pt | 48 | See comments | |
| (Lannate SP) | 1/4– 1 lb | 48 | See comments | |
| MODE-OF-ACTION GROUP NUMBER1: 1A | ||||
| COMMENTS: Preharvest interval is 21 days for roots, 30 days for tops. Highly toxic to bees; do not spray directly or allow to drift onto blooming crops or weeds where bees are foraging. | ||||
| B. | CARBARYL* | |||
| (Sevin XLR Plus) | 1–1 1/2 qt | 12 | 28–roots and forage | |
| MODE-OF-ACTION GROUP NUMBER1: 1A | ||||
| COMMENTS: Highly toxic to bees; do not spray directly or allow to drift onto blooming crops or weeds where bees are foraging. | ||||
| ‡ | Restricted entry interval (REI) is the number of hours (unless otherwise noted) from treatment until the treated area can be safely entered without protective clothing. Preharvest interval (PHI) 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 | Group numbers for insecticides and miticides are assigned by IRAC (Insecticide Resistance Action Committee). Rotate pesticides 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; insecticides with a 1B group number should be alternated with insecticides that have a group number other than 1B. |