Gardener spots caterpillars under strawberries

Daphne Meadows posted images on X on June 1 showing caterpillars tucked beneath coir mulch in a strawberry bed, with the larvae blending closely into the brown fiber. Meadows said the garden had seen “moody skies” and a brief rain that day, a detail that matched the damp, sheltered conditions where several strawberry pests are commonly found. The post drew attention because the insects were not on leaves or fruit in plain view, but hidden under mulch at the base of the plants. Extension guidance from Washington State University and the University of California says that is a familiar pattern for some strawberry-feeding caterpillars. Both institutions describe cutworms and armyworms as larvae that spend daylight hours under debris or near the soil surface, then feed on leaves, buds, flowers or fruit. Mississippi State University’s strawberry pest guide says photos alone are often not enough for a firm diagnosis and recommends pairing images with damage patterns and field scouting. ### Why would caterpillars be hiding under strawberry mulch? Washington State University says cutworms and armyworms “typically spend the day just beneath the soil surface or under debris near the host.” In a strawberry bed, coir mulch can provide that cover, especially after wet weather leaves the material cool and damp. The University of California’s strawberry pest guidelines say cutworms are active night feeders and are commonly hidden at the base of the plant during the day. (hortsense.cahnrs.wsu.edu) Mature larvae may curl into a C-shape when disturbed, a trait gardeners often use as a quick field clue. ### Are these definitely the same as strawberry leafrollers? Washington State University says several different caterpillar pests can occur on strawberries, including leafrollers as well as cutworms and armyworms. (hortsense.cahnrs.wsu.edu) Leafrollers are usually associated with rolled leaves, webbing and, in some cases, fruit tunneling, while cutworms and armyworms are more often found under debris and near the crown or soil surface. (ipm.ucanr.edu) Mississippi State University says “many insects produce similar symptoms on strawberry,” which is why a single photo of a larva is not always enough to name the species. A more reliable check is to look for the combination of where the insect was found, what the body looks like, and what kind of feeding damage is showing up on the plant or berries. (hortsense.cahnrs.wsu.edu) ### What damage should gardeners check for next? The University of California says early cutworm injury can appear as small perforations in expanding leaves, followed later by larger irregular holes, stem cutting, crown injury and holes in fruit. The agency says fruit damage can be concentrated around one to several plants near an active larva. Washington State University says cutworms and armyworms may feed on foliage, buds, flowers or fruit, while leafrollers can leave rolled leaves tied with webbing and may tunnel into berries. (extension.msstate.edu) That means the next inspection should include the crown, the undersides of leaves, any webbed foliage, and ripening berries that touch mulch or plant debris. (ipm.ucanr.edu) ### What do extension experts say to do first? Washington State University lists hand-picking larvae, removing debris around plants and controlling weeds near the bed among the first non-chemical steps for cutworms and armyworms. The agency also advises scratching the soil at the base of damaged plants to find hidden larvae during the day. (hortsense.cahnrs.wsu.edu) For leafrollers, Washington State University recommends picking out rolled leaves and caterpillars, cleaning up leaf debris and avoiding broad-spectrum insecticides that can kill beneficial insects. The guidance says Bacillus thuringiensis works only when caterpillars are actively feeding. ### If a gardener wants to confirm the pest, what is the next move? (hortsense.cahnrs.wsu.edu) Mississippi State University says the best next step is to compare the insect and the injury against extension photo guides rather than relying on a social-media image alone. Washington State University and the University of California both point gardeners toward repeated scouting around the plant base, crown and fruiting area, especially in spring and during active feeding periods. (hortsense.cahnrs.wsu.edu) June berry ripening is the point when that monitoring matters most. UC says cutworms can cause pronounced holes in fruit during harvest, and Washington State University says leafrollers can also damage berries, making the strawberry bed itself the place to watch over the next several days. (hortsense.cahnrs.wsu.edu) (extension.msstate.edu)