Description of the Pest
The orange tortrix is found mainly in coastal areas. The larvae are straw to light green caterpillars with light brown or tan heads. When disturbed, they wiggle backward and drop to the ground on a silken thread. Adults are fawn or gray moths with darker mottling on the forewings. The orange tortrix overwinters as larvae, and there are two to four generations each year in coastal areas.
Damage
Larvae feed on leaves and buds. They also cause shallow feeding injury on the surface of fruits, especially where two fruit are touching. Leaves webbed together to form protective cases indicate their presence.
Management
Orange tortrix is a cyclical pest. In coastal orchards, natural enemies and treatments for other pests usually keep this pest controlled. In other areas treatment is not needed.
Biological Control
Several parasites and predators attack orange tortrix. Parasites include the wasps Cotesia (= Apanteles) aristolidae, Exochus sp., and Hormius basalis and a tachinid fly (Nemorilla pyste). Predators include spiders and brown lacewing larvae (Hemerobius pacificus).
Organically Acceptable Methods
Use the Entrust formulation of spinosad on organically grown apricots.
Monitoring and Treatment Decisions
Spray programs for other insects generally help reduce orange tortrix numbers. The postbloom and May timings for peach twig borer are also effective for orange tortrix.
| 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. | |||||
| A. | SPINOSAD | ||||
| (Entrust)# | 1.25–2.5 oz | 0.42–0.83 oz | 4 | 14 | |
| (Success) | 4–8 fl oz | 1.3–2.7 fl oz | 4 | 14 | |
| MODE-OF-ACTION GROUP NUMBER1: 5 | |||||
| COMMENTS: Most effective when applied at petal fall. This product is toxic to bees for 3 hours following treatment; do not spray directly or allow to drift onto blooming crops or weeds where bees are foraging. Apply in the late evening after bees have stopped foraging. Do not apply more than 29 fl oz/acre per year of Success or 9 oz/acre per year of Entrust. | |||||
| B. | METHOXYFENOZIDE | ||||
| (Intrepid 2F) | 8–16 fl oz | 2–4 fl oz | 4 | 14 | |
| MODE-OF-ACTION GROUP NUMBER1: 18 | |||||
| COMMENTS: Do not apply more than 16 fl oz/acre per application or more than 64 fl oz/acre per season. | |||||
| C. | PHOSMET | ||||
| (Imidan 70-W) | 2.125–4.25 lb | 1 lb | 7 days | 14 | |
| MODE-OF-ACTION GROUP NUMBER1: 1B | |||||
| D. | CHLORANTRANILIPROLE | ||||
| (Altacor) | 3–4.5 oz | 0.75–1.125 oz | 4 | 10 | |
| MODE-OF-ACTION GROUP NUMBER1: 28 | |||||
| COMMENTS: Do not apply more than 9 oz/acre per year or make more than three applications a year. Do not apply with less than 100 or more than 200 gallons water/acre. | |||||
| E. | DIAZINON* | ||||
| (Diazinon 50W) | 1 lb/100 gal | 4 days | 21 | ||
| MODE-OF-ACTION GROUP NUMBER1: 1B | |||||
| COMMENTS: Avoid drift and tailwater runoff into surface waters. Where apricots are grown adjacent to waterways, do not use this material. Do not apply more than 4 lbs product per application. | |||||
| ** | For concentrate applications, use the amount given in 80 to 100 gal water/acre or lower if the label allows; for dilute application, amount is per 100 gal water to be applied in 300 to 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. |
| # | Acceptable for use on organically grown produce. |
| 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 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). |
| * | Permit required from county agricultural commissioner for purchase or use. |