Two spotted spider mite and Cyclamen mite in strawberries
Prepared by Matt Peill (IPM) and Hector Jaldo (Berries)
Hello everyone,
Today we are highlighting two important strawberry pests that should be monitored and managed, as soon as possible, if you have not already done so. The warm, dry conditions typically experienced in July provide an ideal environment for these mites to build rapidly and cause significant crop damage.
For both pests, good spray coverage is essential. Apply miticides with a high volume of water and a non-ionic surfactant according to label instructions, to improve coverage and increase the effectiveness of applications.
Two spotted spider mites (Tetranychus urticae)
Two spotted spider mites are primarily found on the undersides of leaves, especially older leaves. Their feeding damages the leaf, reducing its ability to photosynthesis. Infested leaves may appear dull or dry on the surface, as well as have yellow or tan spotting in some cases. Damaged areas on the underside of the leaves may also appear tan and mites can be easily identified in the field using a hand lens. Two spotted spider mites are difficult to reach with spray applications, making thorough coverage critical for proper management, even with miticides that have translaminar activity (spray moves through the leaf).
Frequent rainfall this season has helped suppress populations by making it more difficult for mites to establish the protective webbing they produce. Once webbing develops, it not only shields the mites from predators but also reduces the effectiveness of miticide sprays by creating an additional barrier on the underside of leaves.
Two spotted spider mite (Tetranychus urticae). Photo: David Cappaert, Michigan State University, Bugwood.org
Overwintered female two spotted spider mite. Photo: University of Maryland extension
Two spotted spider mites. Photo: by Frank Peairs, Colorado State University, Bugwood.org.
Cyclamen mite (Phytonemus pallidus)
Cyclamen mites are typically found in the crown, young still-folded leaves, and within the calyx of newly developing fruit. As populations increase, they spread throughout the plant, causing leaves and fruit to become bronzed, distorted, and stunted.
Early symptoms include deformed or crinkled new leaves. Infestations usually begin as localized hotspots but can spread quickly during harvest through worker activity and equipment. Regular scouting is important to detect infestations before they become widespread. However, cyclamen mites, due to their size, translucent appearance, and where they reside on the plant are not easily identified in the field. Additionally, many of their signs and symptoms can be caused by other physiological conditions, diseases (virus), or pests (thrips). If you suspect cyclamen mites when scouting, please have the infestation confirmed before applying miticides.
Adult female cyclamen mite (yellow arrow), eggs (orange arrows) and larva (red arrow)
Photo: UC Statewide IPM Project, 2000 Regents, Univ. California
Cyclamen mite damage to strawberry fruit. Photo: Ministry of Agriculture, Food and Rural Affairs Ontario Canada
Integrated Pest Management
After your harvest and if mite populations are present, consider making one or two miticide applications while rotating between products with different modes of action. To learn what products are available for mites in strawberries, you can review the current Perennia Small Fruit PestGuide (https://perennia.knack.com/perennia-pest-management-guides#small-fruit-pest-guides/insects-and-diseases/strawberry2/). Some of the products available can be seen in Table 1.
Table 1: Some miticides for controlling Cyclamen mite.
Rotating products helps reduce the risk of resistance development and improve long-term control. After Applying miticides continue to scout fields regularly, paying close attention to hotspots and younger plant growth where infestations often begin. If you have any questions or would like assistance identifying or managing mite infestations, please don't hesitate to contact us (email: Hector Jaldo, hjaldo@perennia.ca and Matt Peill, mpeill@perennia.ca).
Additional Resources