Sampling efficacy and survival rates of Labarrus pseudolividus (coleoptera: scarabaeidae) and Onthophagus taurus (coleoptera: scarabaeidae) using flotation and sieve-separation methodology

Abstract

Understanding collection methodologies and their limitations are essential when targeting specific arthropods for use in habitat restoration, conservation, laboratory colony formation, or when holistically representing local populations using ecological surveys. For dung beetles, the most popular collection methodology is baited traps, followed by light traps and unbaited flight-intercept traps during diversity surveys. A less common collection method, flotation, is assumed to be laborious and messy, and so only a handful of papers exist on its refinement and strengths. Our purpose was threefold: First, we tested the recovery and survival rates of Labarrus (=Aphodius) pseudolividus (Balthasar) and Onthophagus taurus (Schreber) when floating beetleseeded dung pats to determine potential collection and safety issues. We collected 72.4 and 78% of the seeded L. pseudolividus and O. taurus, respectively, with > 95% survival rating. Second, we developed a flotationsieving technique that enables users to rapidly collect and passively sort dung beetles with less time and effort. Specifically, we often collected 50-100 g of wild dung beetles within a couple of hours of gathering dung and sorted them in a couple more by allowing dung beetles to sort themselves by size within a series of sieves; Third, we reviewed flotation-based advantages and disadvantages in comparison to other methodologies.