Auditory Differences in Occupationally Noise-Exposed Workers With Normal Conventional Audiograms: A Multi-Measure Surveillance Approach.

Predator-prey interactions are primary determinants of top-down effects in ecological systems (Finke and Denno ; Schmitz ), significantly influencing ecosystem functions such as nutrient cycling (Ngai and Srivastava ; Schmitz et al. ), primary productivity and pest control (Cain ; Perdikis et al. ). Understanding predator feeding ecology is therefore essential for evaluating their functions in ecosystems, including population regulation mechanisms and competitive interactions among co-occurring predators (Pringle et al. ; Wollrab et al. ). Spiders represent the most ubiquitous generalist arthropod predators in terrestrial ecosystems (Greenstone ), estimated to consume in the realm of 400–800 million tons of prey each year (Nyffeler and Birkhofer ). As such, spiders play a major role in pest control, and have often been used successfully in this role in agriculture (Michalko et al. ). However, the biological control efficiency can be modulated by interspecific interactions, such as intraguild predation (spiders often feed on other spiders), which might reduce overall control efficiency (Finke and Denno ; Michalko et al. ). Additionally, spider diet variability can arise because spider dietary preferences are strongly influenced by their functional traits, such as hunting strategy and body size (Chapman et al. ; Perkins et al. ; Schmidt et al. ). For instance, sit-and-wait spiders specialize in capturing mobile prey, whereas actively hunting spiders are more effective at capturing sedentary prey (Sweeney et al. ). Further, while spiders are generally considered effective predators, they have been observed to experience starvation in the field, with web-building spiders showing greater starvation resistance than hunting spiders (Anderson ; Overgaard and Wang ). Previous research using stable isotope analysis and direct observation of prey remains in spider webs has provided insights into the diet composition and trophic niches of spiders, particularly web-building spiders (Kennedy et al. ; Michalko et al. ; Zuev et al. ). However, significant knowledge gaps remain regarding the high-resolution trophic dynamics of diverse spider communities in complex forest ecosystems. More detailed dietary analysis is required to obtain insights into spider niche partitioning and to better resolve the trophic structure of predator-prey interactions in these ecosystems. Dietary analysis is a fundamental means to define interactions networks at various trophic levels. Predators might vary in prey range (specialization versus generalization), display resource partitioning or overlap in their prey species (niche overlap), while a given species may be preyed upon by a variable number of predator species (prey vulnerability). However, characterizing predator-prey networks is methodologically challenging due to small body size, high mobility, habitat diversity, and dietary complexity of the species involved, particularly for generalists. Traditional dietary analysis methods include field observations, laboratory rearing, analysis of prey remains on webs, and stable isotope analysis. However, these approaches demand taxonomic expertise, are laborious (Kaunisto et al. ), and their accuracy can be limited in some cases, such as those involving external digestion and high mobility (Furlong ). In order to address some of these shortcomings, molecular techniques have been increasingly applied both to gut contents and fecal samples (Sheppard and Harwood ). Particularly, DNA metabarcoding has emerged as a powerful tool for identifying diverse prey taxa (Coissac et al. ; Ji et al. ; Taberlet et al. ). Compared to traditional approaches, high-throughput sequencing offers superior sensitivity for detecting trace DNA while enabling species identification across taxa without requiring morphological expertise. For small predatory arthropods, this approach coupled with short-fragment primers effectively recovers highly degraded prey DNA from digestive systems (Zeale et al. ). However, these molecular approaches are still constrained by their inability to enumerate individual prey items, thereby hindering precise quantification of energy flux or the top-down impacts on prey population dynamics. Nevertheless, DNA metabarcoding remains an indispensable tool for elucidating complex multi-trophic linkages, which constitutes the primary objective of the present study.