Description of the Pest
Greedy scale and latania scale are armored scales and similar in size to adult olive scale and 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, unlike the reddish purple body of the olive scale. The male scale body is much smaller and elongated. It is difficult to distinguish between latania and greedy scales without a microscope, but management for the two species is the same. There are usually several generations a year.
Damage
These scales feed on leaves, bark, and fruit. Infested fruit have a dark purple spot with a distinct outline. The scale is located in the center of the spot. Fruit with scale are rendered worthless.
Management
Biological control plays a significant role in the management of greedy and latania scales. If the previous year's crop had an economic infestation of either of these scales, treatments may be warranted. Control ants in the orchard because they disrupt biological control (for more information, see ANTS).
Biological Control
Several species of Aphytis, including A. melinus, are parasites of these scales. Where insecticides such as carbamates (IRAC Group 1A), organophosphates (1B), and pyrethroids (3) are used, biological control will be disrupted. Be sure to monitor scale populations if disruptive insecticides are used.
Organically Acceptable Methods
Biological control and certain oil sprays are acceptable to use in an organically certified crop.
Monitoring and Treatment Decisions
If treatment is necessary, treat the first brood in late May and June or the second brood in late July and August. Double-sided sticky tape wrapped around tree branches is useful in determining when crawlers are present. Apply first brood treatment when scale crawlers are seen moving on to the fruit. Treating scales between broods in early July is not recommended. A postharvest treatment is also effective.
| Common name | Amount to use** | 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, and the pesticide’s properties and application timing. Always read the label of the product being used. | ||||
| POSTBLOOM (LATE MAY THROUGH JUNE WHEN CRAWLERS ARE PRESENT) | ||||
| A. | NARROW RANGE OIL# | |||
| (Organic JMS Stylet Oil, etc.) | Label rates | 4 | 0 | |
| MODE OF ACTION: Contact including smothering and barrier effects. | ||||
| COMMENTS: Effective against light to moderate infestations, especially when used in conjunction with pruning to open the orchard canopy. Most effective when applied against the crawler stage. Spray at night or early morning if temperatures are expected to exceed 90°F during the day. Check with certifier to determine which products are organically acceptable. | ||||
| B. | PYRIPROXYFEN | |||
| (Esteem 0.86EC) | 13–16 fl oz | 12 | 7 | |
| MODE-OF-ACTION GROUP NUMBER1: 7C | ||||
| COMMENTS: Insect growth regulator. Has no activity on adult stage, but hatching of eggs laid by treated adults will be suppressed. Most effective when applied against the crawler stage. Use higher rate for heavy scale pressure. | ||||
| C. | NARROW RANGE OIL | |||
| (various products) | 1.5 gal | 4 | 0 | |
| MODE OF ACTION: Contact including smothering and barrier effects. | ||||
| COMMENTS: For heavy to severe infestations, add the following insecticide to the oil spray. Spray at night or early morning if temperatures are expected to exceed 90°F during the day. | ||||
| . . . plus . . . | ||||
| CARBARYL* | ||||
| (Sevin SL) | 5.0–7.5 qt | 12 | 14 | |
| MODE-OF-ACTION GROUP NUMBER1: 1A | ||||
| COMMENTS: Do not exceed 2 applications per year. This material is very destructive to most natural enemies. To protect honeybees, apply only during late evening, night, or early morning when bees are not present. For tank mixes, observe all directions for use on all labels, and employ the most restrictive limits and precautions. Never exceed the maximum a.i. on any label when tank mixing products that contain the same a.i. | ||||
| SUMMER (JULY 15–AUGUST) | ||||
| A. | NARROW RANGE OIL# | |||
| (Organic JMS Stylet Oil, etc.) | Label rates | 4 | 0 | |
| MODE OF ACTION: Contact including smothering and barrier effects. | ||||
| COMMENTS: Effective against light to moderate infestations, especially when used in conjunction with pruning to open the orchard canopy. Most effective when applied against the crawler stage. Spray at night or early morning if temperatures are expected to exceed 90°F during the day. Check with certifier to determine which products are organically acceptable. | ||||
| B. | PYRIPROXYFEN | |||
| (Esteem 0.86EC) | 13–16 fl oz | 12 | 7 | |
| MODE-OF-ACTION GROUP NUMBER1: 7C | ||||
| COMMENTS: Insect growth regulator. Has no activity on adult stage but hatching of eggs laid by treated adults will be suppressed. Most effective when applied against the crawler stage. Use higher rate for high scale numbers. | ||||
| C. | NARROW RANGE OIL | 1.5 gal | 4 | 0 |
| MODE OF ACTION: Contact including smothering and barrier effects. | ||||
| COMMENTS: For heavy to severe infestations, add the following insecticide to the oil spray. Do not apply any oil between August 20 and harvest to olives used for Spanish or green-ripe processing due to fruit spotting. Spray at night or early morning if temperatures are expected to exceed 90°F during the day. Check with certifier to determine which products are organically acceptable. | ||||
| . . . plus . . . | ||||
| CARBARYL* | ||||
| (Sevin SL) | 5.0–7.5 qt | 12 | 14 | |
| MODE-OF-ACTION GROUP NUMBER1: 1A | ||||
| COMMENTS: Do not exceed 2 applications per year. This material is very destructive to most natural enemies. To protect honeybees, apply only during late evening, night, or early morning when bees are not present. For tank mixes, observe all directions for use on all labels, and employ the most restrictive limits and precautions. Never exceed the maximum a.i. on any label when tank mixing products that contain the same a.i. | ||||
| POSTHARVEST (OCTOBER–NOVEMBER) | ||||
| A. | NARROW RANGE OIL# | |||
| (Organic JMS Stylet Oil, etc.) | Label rates | 4 | 0 | |
| MODE OF ACTION: Contact including smothering and barrier effects. | ||||
| COMMENTS: Effective against light to moderate infestations, especially when used in conjunction with pruning to open the orchard canopy. Most effective when applied against the crawler stage. Spray at night or early morning if temperatures are expected to exceed 90°F during the day. Check with certifier to determine which products are organically acceptable. | ||||
| B. | NARROW RANGE OIL | 1.5 gal | 4 | 0 |
| MODE OF ACTION: Contact including smothering and barrier effects. | ||||
| COMMENTS: For heavy to severe infestations, add the following insecticide to the oil spray. Spray at night or early morning if temperatures are expected to exceed 90°F during the day. | ||||
| . . . plus . . . | ||||
| METHIDATHION* | ||||
| (Supracide 25WP) | 2 lb | 48 | 0 | |
| MODE-OF-ACTION GROUP NUMBER1: 1B | ||||
| COMMENTS: Use with or without oil. Application of methidathion with, or closely following, a fungicide containing lime will negate the insecticide's effectiveness. The application of this material should precede the application of fungicides containing lime. Do not apply more than 12 lb/acre/year. For tank mixes, observe all directions for use on all labels, and employ the most restrictive limits and precautions. Never exceed the maximum a.i. on any label when tank mixing products that contain the same a.i. To protect honeybees, apply only during late evening, night, or early morning when bees are not present. | ||||
| ** | Amounts per 100 gal water (except where otherwise stated), using 400-500 gal solution per acre. |
| ‡ | 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. |
| * | Permit required from county agricultural commissioner for purchase or use. |
| # | Acceptable for use on organically grown crops. |
| 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). |