No guts, no glory: Gut content metabarcoding unveils the diet of a flower‐associated coastal sage scrub predator

Abstract

Invertebrate generalist predators are ubiquitous and play a major role in food‐web dynamics. Molecular gut content analysis (MGCA) has become a popular means to assess prey ranges and specificity of cryptic arthropods in the absence of direct observation. While this approach has been widely used to study predation on economically important taxa (i.e., pests) in agroecosystems, it is less frequently used to study the broader trophic interactions involving generalist predators in natural communities such as the diverse and threatened coastal sage scrub communities of Southern California. Here, we employ DNA metabarcoding‐based MGCA and survey the taxonomically and ecologically diverse prey range of Phymata pacifica Evans, a generalist flower‐associated ambush bug (Hemiptera: Reduviidae). We detected predation on a wide array of taxa including beneficial pollinators, potential pests, and other predatory arthropods. The success of this study demonstrates the utility of MGCA in natural ecosystems and can serve as a model for future diet investigations into other cryptic and underrepresented communities.

Assessing environmental DNA metabarcoding and camera trap surveys as complementary tools for biomonitoring of remote desert water bodies

“…Environmental DNA from terrestrial animals has been mostly assessed by analyzing scats (De Barba et al, 2014; Kartzinel et al, 2015; Swift et al, 2018), soil (Leempoel et al, 2020; Yoccoz et al, 2012; Zinger et al, 2019), stomach content samples (Kennedy et al, 2019; Masonick et al, 2019; Soininen et al, 2013), leeches blood meals (Abrams et al, 2019; Nguyen et al, 2021; Tilker et al, 2020; Weiskopf et al, 2018; Wilting et al, 2021), or carrion flies (Calvignac‐Spencer et al, 2013; Gogarten et al, 2020; Rodgers et al, 2017; Schubert et al, 2015). Bulk tissue samples (mixtures of, e.g., insects or other macroinvertebrate specimens) are also increasingly used not only to assess invertebrate diversity but also as an indirect way to sample vertebrate DNA (Lynggaard et al, 2019).…”

Identifying Molecular-Based Trophic Interactions as a Resource for Advanced Integrated Pest Management

“…MGCA can also be used to determine the balance of services and disservices by evaluating predation on other beneficial insects in response to habitat management. For example, flower-associated ambush predators feed upon a wide assortment of insects, and were also found to predate bees and other natural enemies [ 61 ]. Therefore, depending on the needs of the agroecosystem and the local community, the use of flowering habitats (which is usually associated with providing resources to beneficial arthropods) could be unfavorable, or could require the careful planting of compatible flowering species, a result that can be elucidated with MGCA.…”

Untitled

“…Like many ambush bugs, P. pacifica is a generalist predator that preys on a broad range of flower visiting arthropods. Molecular evidence suggests that P. pacifica frequently engages in intraguild predation by consuming beetles, parasitoid wasps and flies, crab spiders, and other predatory true bugs (Masonick et al 2019). Adults are relatively common from June through September and may be found living in sympatry with P. metcalfi and P. paraborica sp.…”

“…The genus Phymata Latreille, 1802 (Heteroptera: Reduviidae) comprises ~110 species of ambush bugs distributed primarily in the New World (Froeschner and Kormilev 1989). Their peculiar morphology, sexual dimorphism, and predation on other flowerassociated arthropods have made them popular subjects for evolutionary (Punzalan et al 2008a;Punzalan et al 2008b, c, 2010, Weirauch et al 2011Rowe 2015, 2016), ecological (Balduf 1941;Mason 1977Mason , 1986Yong 2005;Masonick et al 2019), and behavioral research (Dodson and Marshall 1984;Elliott 1991, 1994;Yong 2003;Dixon and Rasmussen 2013). While these sit-and-wait predators are easily distinguished from other true bugs by their raptorial forelegs, fusiform antennae, deep antennal excavations of the head and propleura, and dorsolaterally flared pronotum and abdomen, species-level identification within the genus is confounded by subtle interspecific differences, sexual dimorphism, and intraspecific variation.…”