Description of the Pest
Key to identifying aphids
Rose-grain aphid is a large green aphid that may have a dark green stripe down the middle of the back. It looks similar to greenbug but is larger, the joints in the antennae are darker than the middle portion of the antennae, and the antennae usually reach beyond the base of the cornicles.
Damage
Rose-grain aphids do not inject a toxin as they feed and generally cause very little injury. Since they are easily confused with the more damaging greenbug, care should be taken in identification. If you are not sure of the species, contact your farm advisor before any sprays are applied.
Rose-grain aphid is a vector of BARLEY YELLOW DWARF virus.
Management
Biological Control
Rose-grain aphid is attacked by the natural enemy species discussed under APHIDS–GENERAL CONSIDERATIONS.
Monitoring
Be sure of the species identification before spraying.
Management Decisions
Economic thresholds have not been established for rose-grain aphid.
| 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. | DIMETHOATE | |||
| (Dimethoate 4EC) | 0.50–0.75 pt | 48 | 35 | |
| MODE-OF-ACTION GROUP NUMBER1: 1B | ||||
| COMMENTS: For use on wheat and triticale only. Do not make more than two applications per year. Do not graze within 14 days. Highly toxic to bees; do not spray directly or allow to drift onto blooming crops or weeds where bees are foraging. | ||||
| B. | MALATHION | |||
| (Malathion 8) | 1 pt | 12 | 7 | |
| MODE-OF-ACTION GROUP NUMBER1: 1B | ||||
| COMMENTS: May be used on wheat, barley, oats, and rye. If alfalfa is in bloom, apply during the night or early in the morning when bees are not foraging in the field. 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 these two intervals is the minimum time that must elapse before harvest may take place. |
| * | 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). |