Description of the Pest
Adult earwigs are about 0.5 inch long, shiny brown, and have a pair of forceps-like structures at the back end of the abdomen. They are nocturnal, and their presence or damage may go unnoticed until harvest. There is one generation per year. Females overwinter and lay consecutive broods so there can be two distinct nymph hatchings, one in the late spring and one in the early summer.
Damage
Earwigs feed on fruit and foliage. Foliage feeding is of little concern in mature trees. However, shoot-tip feeding on young trees may stunt normal growth. Earwig feeding results in shallow, irregular feeding areas on the fruit surface.
Management
Management requires the removal of daytime harboring sites and prevention of access to fruit before it ripens.
Cultural Control
Remove weeds from around the base of trees. Keep orchard clear of prunings, loose bark, or debris under which earwigs could nest. Remove tree limbs that come in contact with soil to prevent alternate access to trees.
For a limited number of trees, earwigs could be trapped by applying Tanglefoot or a similar material to the tree to prevent earwigs from crawling up the tree:
- Before emergence of the nymphs, wrap the trunk tightly with plastic wrap so that the insects can't crawl beneath the wrap.
- Apply the Tanglefoot to the plastic wrap, not the tree, as it can soften bark.
- Remove the bands before winter.
This technique is very labor intensive, especially because applications often have to be repeated several times during the season as dust accumulates on the sticky material.
Organically Acceptable Methods
Use cultural controls and the Entrust formulation of spinosad on organically grown apricots.
Monitoring and Treatment Decisions
Place boards, rolled-up newspapers, corrugated cardboard, or cardboard trunk bands in the orchard in early spring and monitor them weekly for the presence of earwigs. Start treatments when earwigs start appearing, because control is best if applications are made when nymphs are emerging and before they move into the tree canopy.
| 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 | ||||
| (Seduce insect bait)# | 20–44 lb | 4 | 14 | ||
| (Entrust)# | 1.25–2.5 oz | 0.42–0.83 oz | 4 | 14 | |
| (Success) | 4–8 oz | 1.3–2.7 oz | 4 | 14 | |
| MODE-OF-ACTION GROUP NUMBER1: 5 | |||||
| COMMENTS: Once high earwig numbers are found in trees a bait application may no longer be effective. Do not spray directly or allow to drift onto blooming crops or weeds where bees are foraging. | |||||
| B. | CARBARYL | ||||
| (Sevin XLR PLUS)* | 3–4 qt | 0.75–1 qt | 12 | 1 | |
| MODE-OF-ACTION GROUP NUMBER1: 1A | |||||
| COMMENTS: Spray on trunks and crotches of trees at the beginning of spring activity. Once high numbers are found in trees such an application will no longer be effective, and a foliar spray, which may cause increased spider mite numbers, is necessary. Do not apply more than 14 qt/acre per crop. | |||||
| ** | 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. |