Evidence of Xysticus ulmi (Hahn) (Araneae: Thomisidae) Predation on Adult Cassida viridis Linnaeus (Coleoptera: Chrysomelidae)

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Evidence of Xysticus ulmi (Hahn) (Araneae: Thomisidae) Predation on Adult Cassida viridis Linnaeus (Coleoptera: Chrysomelidae)

Tortoise beetles (Chrysomelidae: Cassidinae) have several morphological and behavioral antipredator traits. For example, the soft larvae accumulate their feces and exuviae from previous instars to create a so-called “fecal shield” (Engel 1936; Kosior 1975), which functions as a defense against many predator guilds (Eisner and Eisner 2000; Eisner et al. 1968; Vencl et al. 1999, 2005; Vencl and Srygley 2013). Adults are characterized by their explanate and well-sclerotized pronota and elytra, which cover all soft parts of the body, thereby forming a tortoise-shaped shield (Buzzi 1988; Engel 1936; Jolivet 1997; Jolivet and Verma 2002; Selman 1988; Windsor et al. 1992) (Fig. 1A). Furthermore, the adults are known for their ability to grip firmly to surfaces with both tarsal claws and pads, which renders them difficult to capture (Buzzi 1988; Engel 1936; Jolivet and Verma 2002). Although much is known about the natural enemies of and the defensive adaptations by the larval stages of tortoise beetles (e.g., Gomez et al. 1999; Eisner and Eisner 2000; Eisner et al. 1968; Shinohara 2021), the predators and antipredator strategies of adults remain understudied (Shinohara 2021).

Erica Winslott, Kristina Karlsson Green, Maja Tarka "Evidence of Xysticus ulmi (Hahn) (Araneae: Thomisidae) Predation on Adult Cassida viridis Linnaeus (Coleoptera: Chrysomelidae)," The Coleopterists Bulletin, 80(1), 24-27, (20 March 2026) https://doi.org/10.1649/0010-065X-80.1.24