The Preserve at Bull Run Mountains's Journal

Journal archives for July 2022

July 19, 2022

Biodiversity Highlight - Series #1: Lucanidae of the Bull Run Mountains - Part One

Biodiversity Highlight (Series #1: Part One): Platycerus quercus (Oak Stag Beetle)
Virginia Outdoors Foundation - Bull Run Mountains Natural Area Preserve


Platycerus quercus (Oak Stag Beetle) ♀ spotted at the South Section Trails

© Izabella Farr (@izafarr), some rights reserved (CC-BY-NC)


Hello everyone!

Welcome to the first in a new series of posts focusing on the amazing biodiversity held within The Preserve. It has been a while since my last post and new highlights have been irregular (quite the understatement). Today I will be experimenting with some new content to better highlight some of my favorite species that can be observed at The Preserve. To start us off, we will be delving into one of the most interesting families of insects - the Lucanidae, or stag beetles. The Preserve is home to several species of stag beetle, though they are seldom seen. If you've already poured through the project filter you'll see that three different species have been observed on the trails and backwoods of The Preserve. In addition to these three amazing critters, I'll be adding another species that has been observed just outside the preserve and is very likely within the Preserve's border - just waiting to be recorded. These species include:

Dorcus parallelus (Antelope Beetle)
Ceruchus piceus (Red-rot decay stag beetle)
Lucanus capreolus (Reddish-brown stag beetle)
Platycerus quercus (Oak stag Beetle)

Let us start with a little background. Lucanidae is a relatively small family within Coleoptera and contains approximately 1,500 species (It may sound like a lot, but families like Scarabaeidae have over 30,000 species!). The area of the world with the highest Lucanidae diversity in Asia also contains some of the largest and most striking examples of the family. Within the United States the most striking example of a stag beetle is the American giant stag beetle, Lucanus elaphus . The giant stag beetle boasts the largest mandibles of any other North American Lucanidae. L. elaphus is one of my favorite species and a subject of my own research projects, but doesn't occur this far North in Virginia and will not be included on this list. Big mandibles are cool, but bigger doesn't always mean more interesting. You may have already noticed the intimidating mandibles of the male oak stag beetle highlighted below - an interesting feature a common observer may overlook due to the small size of the species. The nuance of morphology in Lucanidae is all the more on show in the smaller species, especially Platycerus.


Platycerus quercus (Oak Stag Beetle) ♂ - male specimen observed in Oklahoma

© Thomas Shahan (@tshahan), some rights reserved (CC-BY-NC)


The namesake of this species is not leaving much to the imagination. The species is most associated with Quercus species throughout its range. As far as common naming conventions go, honesty is always the best way to make a species more reflective of its ecology - the more it makes sense the better (Looking at your earwigs). Typical of the family, the oak stag beetle spends most of its life as a larval grub deep underground in the decaying roots and wood of oak and other hardwood trees. The adult form of the beetle is only a brief period of life in which the beetle emerges from the ground to disperse, compete for females (in regards to males), locate adequate habitat to oviposit (lay eggs - more for the ladies), and end their multiyear journey of life. These periods only last a few months each year, usually between March and June. Females may overwinter to oviposit and can be encountered in the winter months under tree bark or rotting wood cavities. While several studies have been published regarding the general natural history, life cycle, and mating behaviors of this species - there is always more to learn.

Like other species of Lucanidae, the well-endowed mandibles are used for male-on-male combat to secure mating privileges with females. Those recurved, serrated mandibles can be used to bluff another beetle into submission or back up his bravado. Most of the time these battles result in little injury to the combatants. If a smaller contestant decides to push a much larger rival into battle, however, the result can be fatal. Although these natural spectacles are typically out of view for most nature enthusiasts, these tiny forest warriors emphasize the wildness and drama that awaits to be found if one only decides to look a little closer.


ABOUT #BullRunMountainsNaturalPreserve
The Bull Run Mountains are the easternmost mountains in Virginia. Virginia Outdoors Foundation - Bull Run Mountains Natural Area Preserve is approximately 2,350 acres that serve as a living laboratory that sits in the backyard of our nation’s capital. The preserve contains 10 different plant community types and a plethora of regionally uncommon and threatened plant and animal species. In 2002, this land was dedicated by the Virginia Department of Conservation and Recreation as a natural area preserve to protect the unique ecosystems found here. As the owner and manager of the preserve, the Virginia Outdoors Foundation is committed to protecting the special ecosystem found here and sharing it with the public through managed access.

Follow us on Social Media!
iNaturalist: Preserve Manager Joe Villari (@jvillari)
Instagram: @bullrunmountains
Facebook: Virginia Outdoors Foundation (Bull Run Mountains Natural Area Preserve)
Our website: VOF RESERVES: Bull Run Mountains Natural Area Preserve
Meetup Events: Bull Run Mountains Natural Area Preserve Guided Hikes Group

Posted on July 19, 2022 01:22 AM by mjwcarr mjwcarr | 0 comments | Leave a comment

July 26, 2022

Biodiversity Highlight - Series #1: Lucanidae of the Bull Run Mountains - Part Two

Biodiversity Highlight (Series #1: Part Two): Dorcus parallelus (Antelope Beetle)
Virginia Outdoors Foundation - Bull Run Mountains Natural Area Preserve


Dorcus parallelus (Antelope Beetle) ♀ spotted on The Preserve's north section

© Joe Villari (@jvillari), some rights reserved (CC-BY-NC)


Hello again everyone!

Welcome to the second installment of our four-part dive into the Lucanidae, or stag beetles, of the Bull Run Mountains. This week we will be looking at the antelope beetle, Dorcus parallelus. This stag beetle is one of two species of its genus found in North America, both of which are found throughout the eastern portion of the United States. While very few of these have been observed in The Preserve, they seem to prefer the biodiverse quarters found in our northern section. This species of stag beetle is medium-sized, all black, with striated elytra, and modest to medium-sized mandibles (but we'll come back to that). With all our other species of Lucanidae, this gorgeous, albeit incredibly stereotypical-looking beetle has a strong affinity with hardwood tree species like Quercus sp., or oaks - though a thorough ecological investigation has yet to be published (at least I couldn't track one down).

Similar to their sister species in Europe (Dorcus parallelipipedus - thank goodness our species got the easier name), these beetles are frequently encountered in gardens. At least two female specimens have been observed in a garden here on the preserve! This is likely due to the reproductive cycle of the species, which lays its eggs in soil rich in decaying wood and hardwood tree leaves - which may be a large component of a gardeners homemade compost materials. Burrowing into these materials, the female stag beetle will lay her eggs within the substrate where tiny beetle embryos will develop over the next several weeks. Upon hatching the c-shaped, white grub larvae can spend the next one-to-two years feeding and growing underground. Although similar in appearance, these grubs should not be confused with other, more detrimental garden pest species, as they do not feed on living plant materials like roots.


Dorcus parallelus (Antelope Beetle) ♂ - male specimen observed in Ontario

© Bob Noble (@bob15noble), some rights reserved (CC-BY-NC)


Wow, look at those chompers!

The picture above of an adult male specimen illustrates the most charismatic feature of the Lucanidae - the mandibles. These oversized "teeth" are used for male-on-male battles in competition for females. Just like our last highlighted species, Platycerus quercus, these battles can be fierce, though rarely end with the demise of one of the suiters. These relatively large endowments also don't pose much threat to any human handler. Having been chewed on by much larger Lucanidae, this author can attest that the bite force from one of these beetles is more surprise than pain. Interestingly enough, the real pinch comes from the female, whose small pincers are more suited for chewing into decaying wood. These compact mulchers have a bit more torque, bringing a bit more ouch! to your insect encounter.

Taking a step back, our two species Dorcus are just a couple of many distributed across the world. The genus Dorcus is widespread with 30 or more species and found in eastern North America, Europe, and prolifically across India and eastern Asia. Here in the states, the stag beetle diversity is pretty low (unless you decide take some exceedingly long walks through the western California mountain ranges), but how to do even tell a stag beetle from another family of beetles, let alone species?

There are a few easy ways to pick a stag beetle apart from other local beetle fauna. The family may be the best know for their champion antlers, but the morphology of the antenna is a much better indicator of your Coleopteran family. Although not true for every Lucanidae you may come across here in the United States, the elbowed, or geniculate antenna is a major distinguishing feature of the family. As you can see in the photo above, the antenna of this male D. parallelus possesses an extended initial antennal segment , followed by a series of smaller segments leading into a distal club. This trait can also be observed in our last species and will be a persistent feature as we review additional Lucanidae here at the Preserve. As we continue our exploration of Lucanidae I'll highlight the more subtle morphological features to help with identification.


ABOUT #BullRunMountainsNaturalPreserve
The Bull Run Mountains are the easternmost mountains in Virginia. Virginia Outdoors Foundation - Bull Run Mountains Natural Area Preserve is approximately 2,350 acres that serve as a living laboratory that sits in the backyard of our nation’s capital. The preserve contains 10 different plant community types and a plethora of regionally uncommon and threatened plant and animal species. In 2002, this land was dedicated by the Virginia Department of Conservation and Recreation as a natural area preserve to protect the unique ecosystems found here. As the owner and manager of the preserve, the Virginia Outdoors Foundation is committed to protecting the special ecosystem found here and sharing it with the public through managed access.

Follow us on Social Media!
iNaturalist: Preserve Manager Joe Villari (@jvillari)
Instagram: @bullrunmountains
Facebook: Virginia Outdoors Foundation (Bull Run Mountains Natural Area Preserve)
Our website: VOF RESERVES: Bull Run Mountains Natural Area Preserve
Meetup Events: Bull Run Mountains Natural Area Preserve Guided Hikes Group

Posted on July 26, 2022 06:20 PM by mjwcarr mjwcarr | 0 comments | Leave a comment