Description of the Pest
The black cherry aphid is large and shiny metallic black. This pest overwinters as shiny black eggs on twigs and fruit spurs. Eggs hatch shortly before bloom and the aphids can go through a number of generations and may become very abundant in early spring. The population decreases to a very low level on cherry trees during the summer months and primarily survives on mustard family weeds during this period.
Damage
High populations of the black cherry aphid are mainly a problem on young trees where they cause curling and distortion of the leaves.
Management
The best time to control black cherry aphid is during the dormant or delayed dormant period. In addition, a number of natural enemies, including lady beetles, lacewings, and several species of parasitic wasps, help keep aphid populations controlled. Assess populations at bloom. (For more information, see MONITORING PESTS AT BLOOM.) If control has not been achieved during the dormant period and natural enemies are not adequately controlling the population, apply a treatment shortly after petal fall.
| Common name | Amount to use** | REI‡ | PHI‡ | ||
|---|---|---|---|---|---|
| (Example trade name) | (conc.) | (dilute) | (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. | |||||
| DORMANT OR DELAYED-DORMANT | |||||
| A. | NARROW RANGE OIL | Label rates | See label | 0 | |
| MODE OF ACTION: Improves translaminar movement and insecticide persistence. | |||||
| . . . PLUS . . . | |||||
| DIAZINON* | |||||
| (Diazinon 50W) | 1 1/4 lb/100 gal water | 96 (4 days) | 21 | ||
| MODE-OF-ACTION GROUP NUMBER1: 1B | |||||
| COMMENTS: Organophosphate insecticides used during delayed dormancy are very toxic to honey bees. Remove bees from orchard if cover crops or weeds are in bloom. Oil sprays may injure trees that are water stressed. It is advisable to postpone an oil application to water-stressed trees until winter rains have replenished soil water and the tree bark is noticeably moist. Avoid drift and runoff into surface water or choose alternative materials. Diazinon has been found in surface waters at levels that violate federal and state water quality standards. | |||||
| PETAL FALL | |||||
| A. | IMIDACLOPRID | ||||
| (Admire Pro) | 1.4–2.8 fl oz/acre | 12 | 7 | ||
| MODE-OF-ACTION GROUP NUMBER1: 4A | |||||
| COMMENTS: Highly toxic to bees; do not spray directly or allow to drift onto blooming crops or weeds where bees are foraging.
Review and follow the California neonicotinoid regulations effective January 1, 2024. Permissible application rates of this insecticide may be lower than label rates if applying more than one neonicotinoid active ingredient or using more than one application method in the same season. |
|||||
| B. | THIAMETHOXAM | ||||
| (Actara) | 3–4 oz/acre | 12 | 14 | ||
| MODE-OF-ACTION GROUP NUMBER1: 4A | |||||
| COMMENTS: May only be applied once after bloom. Do not apply by air. Highly toxic to bees; do not spray directly or allow to drift onto blooming crops or weeds where bees are foraging.
Review and follow the California neonicotinoid regulations effective January 1, 2024. Permissible application rates of this insecticide may be lower than label rates if applying more than one neonicotinoid active ingredient or using more than one application method in the same season. |
|||||
| C. | ACETAMIPRID | ||||
| (Assail 30SG) | 2.5-5.3 oz | 12 | 7 | ||
| MODE-OF-ACTION GROUP NUMBER1: 4A | |||||
| COMMENTS: Toxic to bees; do not spray directly or allow to drift onto blooming crops or weeds where bees are foraging. | |||||
| D. | DIAZINON* | ||||
| (Diazinon 50W) | 1 lb/100 gal water | 96 (4 days) | 21 | ||
| MODE-OF-ACTION GROUP NUMBER1: 1B | |||||
| COMMENTS: Avoid drift and tailwater runoff into surface waters. Where cherries are grown adjacent to waterways, do not use this material. Highly toxic to bees; do not spray directly or allow to drift onto blooming crops or weeds where bees are foraging. | |||||
| ** | For concentrate applications, use the amount given in 80–100 gal water/acre, or lower if the label allows; for dilute applications, amount is per 100 gal water to be applied in 300–400 gal water/acre, according to label. |
| ‡ | 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 | 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). |