Role of Lygus hesperus (Hemiptera: Miridae) Adult Feeding on Deformation of Blackberry Fruits

Abstract

Blackberry (Rubus fruticosus L.; Family, Rosaceae) is ranked within the top three and top 25 agricultural crops in Santa Cruz and Monterey counties in California (Central Coast), respectively. The value of blackberry in Santa Cruz Co. has been estimated at ; US$52.8 million and has been planted on 367.5 ha (Santa Cruz County Crop Report 2019), while it has been valued at ; US$13.5 million and grown on 91.6 ha in Monterey Co. (Monterey County Crop Report 2019). Blackberry is produced continuously from June to October on the Central Coast of California. The crowns of blackberry plants are perennial, and their canes bear fruits. Many arthropod pests pose a threat to blackberry, such as apple pandemis (leafroller), Pandemis pyrusana Kearfott; omnivorous leafroller, Platynota stultana Walsingham; orange tortix, Argyrotaenia citrana (Fernald); redberry mite, Acalitus essigi (Hassan); white apple leafhopper, Typhlocvyba pomaria Walh; rose leafhopper, Edwardsiana rosae (L.); spotted-wing drosophila, Drosophila suzukii Matsumura; and greenhouse whitefly, Trialeurodes vaporariorum (Westwood) (Bolda and Bettiga 2015, Univ. California IPM Pest Management Guidelines: Caneberries, UC ANR Publication 3437). In recent years, widespread incidences of deformed blackberry fruits have been reported in many blackberry production farms in the Central Coast of California (Fig. 1A). Blackberry fruit deformation can be caused by insufficient pollination after irregular wind, rain, and extreme temperature events (Martin et al. 2017, Compendium of raspberry and blackberry diseases and insects. APS Press, 83– 85). Adults and nymphs of the western tarnished plant bug, Lygus hesperus Knight (Hemiptera: Miridae), have been regularly observed on blackberry canes during the fruiting season on many farms from the midto late-season (S.V.J. and M.B.,