Includes larger raspberry aphid (Amphorophora agathonica)
Pest description and crop damage Several different aphids can be found in caneberries but the major aphid pest of caneberries is the larger raspberry aphid. This aphid is large, up to 3 mm long, when compared to other species; they are dark green to yellow.
Large populations of aphids weaken and stunt new growth. Aphid feeding causes yellowing of foliage, deformed leaves, and can devitalize plants. They also exude sticky honeydew which results in sooty mold. The honeydew and mold can reduce the quality of fruit, and also attracts ants and yellow jackets. The major problem, though, is virus diseases, which the aphid can transmit readily.
Biology and life history The larger raspberry aphid overwinters as eggs on the canes. The eggs are light yellowish-white when laid in November, but later turn black. Eggs begin hatching by late February or March. The population increases slowly after that, with several overlapping generations per year. Winged forms, which lay the overwintering eggs, are produced in fall.
Scouting and thresholds Check plants frequently after new growth begins. Aphids often are concentrated in "hot spots." Be sure to look for evidence of biological control; i.e., the presence of predators, parasites (aphid mummies), and disease. Aphid flights are most common during periods of moderate temperatures (60° to 80°F).
Many parasites and predators attack aphids. Monitor the proportion of aphid mummies to unparasitized adults and the number of predators such as lady beetles. If the biocontrol agents appear to be gaining control, avoid sprays which would disrupt this system. Most products available for aphid control are highly disruptive of natural enemies.
Aphid populations tend to be higher in plants that are fertilized liberally with nitrogen. Prune out suckers and other excess growth that might encourage colonization of the aphids.
Home gardeners: Wash aphids from plants with a strong stream of water. Control ants, which "farm" the aphids that protect them from predators.
Management-chemical control: HOME USE
- superior-type oil-Some formulations are OMRI-listed for organic use.
Avoid making applications of insecticides to plants in bloom to avoid bee injury. Follow all label directions.
- azadirachtin (neem oil)-Some formulations are OMRI-listed for organic use.
- insecticidal soap-Some formulations are OMRI-listed for organic use.
- kaolin-Applied as a spray to leaves, stems and fruit it acts as a repellent to some insect pests. Some formulations are OMRI-listed for organic use.
- permethrin (for use on raspberries only)
- pyrethrins (often as a mix with other ingredients)-Some formulations are OMRI-listed for organic use.
Management-chemical control: COMMERCIAL USE
- acetamiprid (Assail) at 0.044 to 0.1 lb ai/a. PHI 1 day. Do not exceed 0.5 lb ai/a per season.
- esfenvalerate (Asana XL) at 0.025 to 0.05 lb ai/a. PHI 7 days. Asana can act as a bee repellent; do not apply within 7 days of pollination. Apply pre-bloom or post-bloom only. Remove bees before applying. For maximum bee safety, apply in the evening after sunset. Because of pollinator hazard, WSU entomologists do not recommend its use on red raspberries.
- flupyridifurone (Sivanto) at 0.09 to 0.18 lb ai/a. PHI 0 days. Toxic to adult bees in laboratory studies via oral exposure, however, not toxic to bees through contact exposure, and field studies conducted with this product have shown no effects on honeybee colony development. Two applications, 7 days apart, and no more than 0.365 lb ai/a allowed per season. Avoid rotation with neonicotinoid products, if possible.
- imidacloprid (Admire Pro and other brands) at 0.1 lb ai/a for foliar applications, and 0.25 to 0.5 lb ai/a for soil applications. (Check label of other brands for correct foliar rate). PHI 3 days (foliar) or 7 days (soil). Do not apply pre-bloom, during bloom or when bees are foraging. Note "Bee Advisory Box" and restrictions on the label.
- insecticidal soap (M-Pede and other brands)-Consult label for rate. Some formulations are OMRI-listed for organic use. PHI 0 days.
- malathion (several brands) at 1.5 to 2 lb ai/a. PHI 1 day. Do not use during bloom.
- pyrethrin (several brands)-Consult label for rate and use directions. PHI 0 days. PyGanic brand is OMRI-listed for organic use.
- thiamethoxam (Actara) at 0.031 to 0.047 lb ai/a. PHI 3 days. Do not apply during bloom or when bees are foraging in the area. Note "Bee Advisory Box" and restrictions on the label.