Pest description and crop damage The adult is a blue-black clear-wing moth with yellow markings. In both sexes there is a prominent, shield-like tuft of long scales at the posterior end of the abdomen; it is larger and more flattened in the male. Wings are transparent and normally spread out while the moth is at rest. They are mostly devoid of scales except on the veins, which generally are black with golden-purplish markings. A fringe of long, pale purplish scales borders the exposed posterior margin of the wings. Each forewing has an area of black scales about two-thirds from the body. Red currants are the most susceptible host.
Biology and life history The insect overwinters as an inactive, nearly mature larva just above the ground on the canes. These larvae feed for a short time in the spring, chew a hole in the side of the cane, then cover the hole with silk and pupate in the cane. Adult moths emerge from the canes in June and July; they are active on bright, warm days. Adults mate and the females deposit eggs singly near nodes, pruning scars, or under loose bark.
Scouting and thresholds Inspect canes at the base of the plants for larval populations when larvae are active in the spring.
Little is known about the role natural enemies play in control. Overwintering larvae are often prey to a parasitic wasp and a fungal disease which helps reduce borer populations.
Home gardeners: Remove infested canes and destroy them.
Management-chemical control: HOME USE
- insecticidal soap-Some formulations OMRI-listed for organic use.
- plant essential oils (cinnamon, peppermint, thyme)-Some formulations are OMRI-listed for organic use.
Management-chemical control: COMMERCIAL USE
The following insecticides are registered for use in gooseberries and currants and, although currant borer does not appear on the labels, these products are known to control other lepidopteran larvae and might be effective in controlling the currant borer. Targeting the young larvae when they are exposed and before they have entered woody stem tissue is critical for successful control.
- bifenthrin (Brigade and other brands) at 0.033 to 0.1 lb ai/a. PHI 1 day. Toxic to bees; do not use when bees are foraging. Also toxic to fish and other aquatic invertebrates. Do not exceed 0.5 lb ai/a per season.
- chlorantraniliprole (Altacor) at 0.066 to 0.99 lb ai/a. PHI 1 day. Do not apply more than 0.2 lb ai/a per year.
- fenpropathrin (Danitol) at 0.2 to 0.3 lb ai/a. PHI is 3 days; PHI for currants is 21 days. Do not exceed 0.6 lb ai/a per season. Toxic to bees; do not use when bees are foraging. Also toxic to fish and other aquatic invertebrates. Restricted use pesticide.
- indoxacarb (Avaunt) at 0.065 to 0.11 lb ai/a. PHI 7 days. Toxic to bees; do not use when bees are foraging. Also toxic to fish and other aquatic invertebrates.
- methoxyfenozide (Intrepid and others) at 0.16 to 0.25 lb ai/a. PHI 7 days. Apply when egg laying begins and young larvae are present. Do not exceed 0.75 lb ai/a per year.
- novaluron (Rimon and Cormoran)-Check label for rate. PHI 8 days. Apply when larvae are young and small.
- spinetoram (Delegate) at 0.05 to 0.08 lb ai/a. PHI 3 days. Toxic to bees exposed to treatment for 3 hours following treatment. Do not use when bees are foraging. Also toxic to fish and other aquatic invertebrates.
- spinosad (Entrust and others) at 0.06 to 0.09 lb ai/a. PHI 1 day. Entrust is OMRI-listed for organic use. Apply at egg hatch or to small larvae. Toxic to bees exposed to treatment for 3 hours following treatment. Do not use when bees are foraging. Also toxic to fish and other aquatic invertebrates.
- zeta-cypermethrin (Mustang) at 0.05 lb ai/a. PHI 1 day. Toxic to bees; do not use when bees are foraging. Also toxic to fish and other aquatic invertebrates. Restricted use pesticide.