Description of the Pest
Key to identifying aphids
The English grain aphid is a yellow-green to reddish brown, medium sized aphid with black antennae, cornicles, and leg joints. It usually appears later in the season than the other cereal aphids.
Damage
English grain aphid is found on the leaves and stem of barley and oats, but in wheat it frequently colonizes the heads. It causes little injury except in wheat when present in extremely high numbers, more than 80 to 100 per head. It is thought that large amounts of honeydew produced by this aphid, particularly when in the head, may clog harvesting equipment; however, this has not been confirmed.
English grain aphid is a vector of BARLEY YELLOW DWARF virus.
Management
Biological Control
English grain aphid is normally suppressed by the common aphid parasites and predators (see APHIDS–GENERAL CONSIDERATIONS).
Monitoring
Be sure to check for presence of this aphid in the heads when monitoring wheat.
Management Decisions
Economic thresholds have not been established.
| 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) | 0.5–0.75 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). |