Tierra de Oro Laboratory

Physiology and Ecology in the Pinyon-Juniper Savanna

Category: updates

  • Setting Up Pitfall Traps for Beetle Surveys in 2025

    Starting surveys for 2025

    Photo of grassland with a small cholla cactus in the center foreground, small juniper and pinyon on the right side, and larger junipers in the background. Small blue flags are located at regular intervals.
    Trap location, looking northeast. Small blue flags remain in place to mark locations of traps. One trap, with a painted cover held down by a rock, can be seen in front of the cholla cactus. 3/3/25.

    Inspired by comments from my friend and colleague Dr. Drew Talley, and conversations with a local Master Gardener, we set up a small array of pitfall traps to collect and record beetles over the course of the year.

    It is a 3 X 3 grid, so nine traps total, spaced 3 meters apart. We set out flags to mark the locations of the traps in a section of the back acre of the lab where foot traffic was minimal.

    Blue plastic cup buried in red sand surrounded by grasses.
    Pitfall trap, consisting of a plastic cup buried to the rim . Note that the rim is flush with the soil. 3/4/25.

    The traps are plastic party cups, buried to the rim. The soil is quite loose, so placing the traps was easy.

    Painted wooden square, with legs partially buried in soil. Rock on top.
    Pitfall trap with plywood cover. Legs are partially buried, leaving space for entry of beetles. 3/4/25

    Once the traps were in place, we put plywood covers over them to keep debris out and shield any animals that fall in.

    Plywood covers with wooden legs, unpainted.
    Plywood covers for pitfall traps before painting. Covers are 6 X 6 pieces of plywood with 3/4 wooden dowels screwed into place.

    The covers are 6″ X 6″ pieces of plywood, each with three legs made from 3/4″ dowels. The 3″ legs allow them to be partially buried for stability. Once screwed together they were given a few coats of latex paint to protect them from the elements.

    We’ll set traps for the first week of each month, for five nights at a time.

    I have not seen beetles in the neighborhood before April, so it is unlikely any will fall into the traps this month. Knowing when beetles are not active provides an important baseline for when they first appear.

  • It Resembles a Web Site

    As anyone who knows me will tell you, my motto is “never let the good be the enemy of the adequate.” The site is up and running, if nowhere near perfect.

    The Front Page is ready, and provides jumping off points for the major sections of the site.

    There is a Wildlife page, which will ultimately direct visitors to informal discussions of local flora and fauna. At the moment, one can find information about some of the local Beetles.

    The Projects page describes the work that we are doing here. The page describing the Beetle Metabolism and Ecology project has been published, along with information about Respirometry. Pages describing the other projects are coming soon.

    The Blog continues, with this entry being the most current.

    Finally, we have added a collection of Quick Links to the Front Page, allowing visitors to jump to their areas of interest without having to navigate multiple pages.

    Thank you for joining us on this journey of discovery. More pages will be going live, including links to resources and descriptions of the work we are doing.

  • New Beetles!

    Bluish-black beetle with rough thorax and elytra held in fingers

    I got a shipment of 15 blue death-feigning beetles (Asbolus verrucosus) yesterday from Bugs in Cyberspace. If the goal of the lab is to study the biology of the local wildlife of the semi-arid savannah, why would I be interested in Asbolus, a creature from the hot, dry Sonoran and Mojave deserts? Well, aside from them being cute, lumpy, blueish, and acting like they are dead (see below), their biology is worth a look. Compared to the local species of Eleodes and Philolithus, Asbolus is adapted to much more extreme conditions, with scarce resources and high temperatures. One reported adaptation for these difficult conditions is a much lower metabolic rate than those I have measured for Eleodes and Philolithus. However, the experiments were done long ago and under different conditions. When I saw that these guys were available online, it seemed like an excellent opportunity to revisit their oxygen consumption and temperature sensitivity.

    Tenebrionid beetles, like Eleodes, Philolithus, and Asbolus, employ thanatosis, or playing dead, as a defensive strategy. With Eleodes and Philolithus, I am accustomed to them freezing for a while during handling, but it is not particularly convincing. Most of the time they try to wiggle away rather than playing dead.

    Bluish-black beetle lying on its back playing dead
    Don’t eat me, I’m dead.

    Asbolus, on the other hand, lives up to its name of death-feigning beetle, and fakes its own death at every opportunity. Whenever they are handled, they turn over and stick their legs out like cartoon characters, and will do so repeatedly. This may be their only choice. They have no defensive stink glands (like Eleodes), nor do they mimic a stinky species (as Philolithus mimics Eleodes), so playing dead may be the most effective strategy.

    They will need to settle in for a few weeks before experiments get started, and the real test will be in the summer when all of the local beetles have their metabolisms at full throttle.