Cryptomyzus ribis
Pest description and crop damage This aphid is commonly found on currants and occasionally found on gooseberries. Adult aphids are greenish yellow and about 2 mm long. Immature aphids are yellowish in color. Eggs are shiny black. Aphid feeding on leaves causes a cupping, distortion, and red color. Feed can cause some loss of plant vigor. Honeydew accumulation, and associated sooty mold, on foliage and fruit is unsightly and can reduce fruit quality.
Biology and life history The currant aphid overwinters in the egg stage on bark or new canes. Eggs hatch in early spring, about the time leaf buds begin to open. The young aphids begin to feed immediately on leaves and leaf buds. This generation feeds for about 12 to 14 days, reaches adulthood, then produces not eggs but living young. Several such wingless generations are produced each summer. As fall approaches, winged forms are produced that mate and lay eggs on the canes to overwinter.
Scouting and thresholds Check plants frequently after new growth begins. Aphids are often concentrated in "hot spots" in the field. Be sure to also look for evidence of biological control; i.e., the presence of predators, parasites (aphid mummies will be apparent), and disease. Aphid flights are most common during periods of moderate temperatures (60° to 80°F).
Management-biological control
Many naturally occurring 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.
Management-cultural control
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.
Home gardeners: Wash aphid from plants with a strong stream of water. Control ants, which "farm" the aphids and protect them from predators. A narrow band of "stickem" at the base of the stem should exclude ants. Use a floating row cover where feasible.
Management-chemical control: HOME USE
Dormant-season spray
- superior-type oil-Some formulations OMRI-listed for organic use.
Growing-season spray
- acetamiprid
- azadirachtin -Some formulations are OMRI-listed for organic use.
- bifenthrin
- esfenvalerate (gooseberry only)
- horticultural oils
- imidacloprid
- insecticidal soap-Some formulations OMRI-listed for organic use.
- kaolin-When 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.
- neem oil-Some formulations are OMRI-listed for organic use.
- plant essential oils (cinnamon, clove, garlic, peppermint, rosemary, thyme)-Some formulations are OMRI-listed for organic use.
- pyrethrins
- spinosad
- zeta-cypermethrin
Management-chemical control: COMMERCIAL USE
- acetamiprid (Assail) at 0.047 to 0.10 lb ai/A. PHI 1 day. Do not exceed 0.5 lb ai/A per season. Toxic to bees when exposed to direct treatment.
- azadirachtin (Ecozin and other brands)-Consult label for rate. PHI 0 days. Some formulations are OMRI-listed for organic use.
- Beauveria bassiana (BioCeres and others)-Consult label for rate. PHI 0 days. OMRI-listed for organic use.
- bifenthrin (Brigade 2EC and others) at 0.033 to 0.10 lb ai/A. PHI 1 day. Hazardous to bees. Restricted use pesticide.
- Burkholderia spp. (Venerate XC)-Consult label for rate. PHI 0 days. To minimize exposure to bees, to not apply when bees are foraging.
- cinnamaldhyde (Seican)-Consult label for rate. PHI 0 days.
- cyantraniliprole (Exirel) at 0.088 to 0.133 lb ai/A. PHI 3 days. Toxic to bees; do not use when bees are foraging. Note "Bee Advisory Box" and restrictions on the label. Also toxic to fish and other aquatic invertebrates.
- fenpropathrin (Danitol 2.4EC) at 0.2 to 0.3 lb ai/A. PHI 3 days. Hazardous to bees. Restricted use pesticide.
- flupyridifurone (Sivanto HL, Altus) at 0.09 to 0.18 lb ai/A. PHI 3 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 (Malice 75SWP, Imidashot DF) at 0.037 to 0.051 lb ai/A. PHI 3 days. Foliar application. Apply when aphids appear. Do not apply prior to or during bloom. Toxic to bees; do not use when bees are foraging. Note "Bee Advisory Box" and restrictions on the label. Also toxic to fish and other aquatic invertebrates. Do not exceed 5 applications per year.
- insecticidal soap (M-Pede and other brands)-Consult label for rate. PHI 0 days. Some formulations are OMRI-listed for organic use.
- malathion-Consult label for rate. PHI 1 day. Apply in at least 100 gal/A water. Apply when aphids appear on leaves and cupping begins. Toxic to bees; do not use when bees are foraging. Also toxic to fish and other aquatic invertebrates.
- pyrethrins (several brands)-Consult label for rate and use directions. PHI 0 days. Direct contact is essential for effective results. Toxic to bees; do not use when bees are foraging. Also toxic to fish and other aquatic invertebrates. Many brands, such as Pyganic, are OMRI-listed for organic use.
- spirotetramat (Movento) at 0.13 to 0.16 lb ai/A. PHI 7 days. Hazardous to bees; do not apply until after petal fall.
- sulfoxaflor (Transform WG) at 0.023 to 0.047 lb ai/A. PHI 1 day. Highly toxic to bees exposed to direct treatment.
- thiamethoxam (Actara) at 0.047 to 0.062 lb ai/A. PHI 3 days. Foliar applied. Actara and Platinum have the same active ingredient; for resistance management, do not follow one with the other. Toxic to bees; do not use when bees are foraging. Note "Bee Advisory Box" and restrictions on the label. Also toxic to fish and other aquatic invertebrates. Do not exceed 0.188 lb ai/A of thiamethoxam-containing products per growing season.
- thiamethoxam (Platinum) at 0.078 to 0.188 lb ai/A. PHI 75 days. Soil applied. Apply to the soil and incorporate with irrigation. Actara and Platinum have the same active ingredient; for resistance management, do not follow one with the other. Do not apply when bees are foraging. Wait at least 5 days after application before placing beehives in treated field. Note "Bee Advisory Box" and restrictions on the label. Do not exceed 0.188 lb ai/A of thiamethoxam-containing products per growing season.
- tolfenpyrad (Bexar) at 0.28 lb ai/A. PHI 3 days. Hazardous to bees.