Description of the Pest
The planthopper (often incorrectly referred to as a "fulgorid" but actually a member of the planthopper family Delphacidae, subfamily Delphacinae) may be abundant on bermudagrass florets and leaves from mid-spring through fall. Metadelphax propinqua is a small, tan planthopper, about 0.13 inch (3-4 mm) long. Two distinguishing traits of Delphacid planthoppers are prominent, thickened antennae and a spur at the base of the hind tarsi that points inward. Adult planthoppers can be observed hopping and flying when disturbed. The nymphs resemble adults but are wingless.
In other areas it has been noted that this species has short-winged, intermediate-winged, and long-winged forms. The average lifespan is about 50 days, and depending on location, there are 3 to 10 generations a year.
Damage
Adults and nymphs may be found in bermudagrass at any time during spring and fall seed-production seasons and are of greatest concern when plants are in bloom. Their feeding reduces plant vigor, but more serious is the contamination of seed heads with honeydew deposits that make the seed difficult to harvest and clean.
Management
Monitor seed fields with a sweep net for planthoppers when florets are developing and continue through seed harvest. No threshold is established; however, in a commercial field study, a level of 12 leafhoppers per 90° sweep was not high enough to cause seed harvest problems.
| 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 label of product being used. | ||||
| A. | ACEPHATE | |||
| (Orthene) 75S | 1.33 lb | 24 | 0 | |
| MODE OF ACTION GROUP NUMBER1: 1B | ||||
| COMMENTS: Available for use under a 24(c) registration. Do not feed crop residue to livestock or allow animals to graze treated areas. Do not apply this product through any type of irrigation system. | ||||
| ‡ | Restricted entry interval (REI) is the number of hours 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 the two intervals is the minimum time that must elapse before harvest. |
| 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). |