Description of the Pest
Scale insects are found infesting the leaves, cordons, canes, and fruit of kiwifruit vines.
Greedy scale and latania scale are armored scales and similar in size to adult oleander scale. However, the waxy shell covering of these two species is more conical with a small black spot or nipple to one side of the center. If the shell is removed, the female body is yellow. The male scale body is much smaller and elongated. It is difficult to distinguish between latania and greedy scales without a microscope, but identification is not necessary for management. There are usually several generations a year.
The adult female oleander scale is an armored scale that is about 0.1 inch (2.5 mm) long and oval. It has a waxy covering with a yellow or light brown spot near the center. The adult male scale is elongate. If the coverings are removed, the female body is yellow, while the male scale is brownish yellow. There are several generations a year.
Damage
Scale insects feed on plant fluids and can be located on the bark or fruit of kiwi. Heavy infestations affect the vigor of the plant and result in the presence of scales on fruit, causing it to be offgraded.
Management
Although management for all three species is the same, biological control may play a significant role in the management of greedy and latania scales. If the previous year's crop had an economic infestation of any of these scales, treatments are warranted.
Biological Control
Various predatory insects and parasitic wasps kill armored scales. Parasites include species of Aphytis wasps and predators include green lacewings, brown lacewings, minute pirate bugs, and small species of lady beetles.
Organically Acceptable Methods
Biological control and certain oil sprays are acceptable to use in an organically certified crop.
Monitoring and Treatment Decisions
Evidence of scale on canes during dormant pruning or off-grade fruit at harvest caused by the presence of scales is justification for a treatment. Treatments are applied during the dormant period after pruning and tying to permit better spray coverage, but before budbreak to avoid phytotoxicity. Double-sided sticky tape wrapped around vine cordons is used to determine when crawlers are present. Monitoring scale crawler populations is beneficial in determining efficacy of the delayed-dormant treatment.
| Common name | Amount per acre | REI‡ | PHI‡ | |
|---|---|---|---|---|
| (Example trade name) | (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, the pesticide's properties, and application timing. Always read the label of the product being listed. | ||||
| DORMANT | ||||
| A. | PYRIPROXYFEN | |||
| (Seize 35WP) | 4–5 oz | 12 | 30 | |
| MODE-OF-ACTION GROUP NUMBER1: 7C | ||||
| COMMENTS: Use higher rates for high numbers of scales. | ||||
| . . . PLUS . . . | ||||
| NARROW RANGE OIL# | ||||
| (PureSpray Green, IAP 440 spray oil) | 1 gal | 4 | NA | |
| (Omni Supreme Spray) | 1 gal | 12 | NA | |
| B. | NARROW RANGE OIL# | |||
| (PureSpray Green, IAP 440 spray oil) | 4–6 gal/100 gal water | 4 | NA | |
| (Omni Supreme Spray) | 4–6 gal/100 gal water | 12 | NA | |
| MODE OF ACTION: Contact including smothering and barrier effects. | ||||
| COMMENTS: For organically grown crops, check with your certifier to determine which products are organically acceptable. Use higher rates for high numbers of scales. | ||||
| ‡ | 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 organically grown produce. Check with your certifier if permissible. |
| 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). |
| NA | Not applicable |