On the evening of May 15th, 2015 I participated in a Bioblitz at the Shale Hollow Preserve. This is a park maintained by Preservation Parks of Delaware County, and is located just west of St. Rt. 23 in Delaware Ohio. The Shale Hollow stream sits in a corridor of 20 to 40 foot tall cliffs of shale, hence the name of Shale Hollow. Within the stream bed one can find concretions, which are carbonate spheres that range in diameter from a few inches to over 9 feet (Hansen 1994). They are really interesting geological features, and if you are curious you can read more about them in the Geofacts publications from ODNR. The stream, forests, and cliffs create a beautiful habitat, that I thoroughly enjoyed seeing. It is home to many species of birds, amphibians, mammals, and invertebrates.
I only had a couple of hours available in which to search for spiders, but I was not disappointed. Spiders can be notoriously difficult to identify, often one needs a mature specimen under a microscope in order to correctly determine the genus and species. Neriene radiata, the filmy dome spider, is one exception to that rule, and actually it is easiest to identify the species by the web it makes (Bradley and Buchanan 2013) . The common name of filmy dome accurately describes the dome style sheet web that the spider constructs, which is four to five inches in diameter usually within a couple feet of the ground (Weber 2013). The spider will live on the underside of the dome, sitting inverted waiting for prey to get knocked down by the tangle of threads above the dome, and then drop onto the dome’s surface where she can pull the prey through the web (Howell and Jenkins 2004). I usually have a spray bottle filled with water which is the perfect tool for highlighting the shape and density of the web.
The family Corinnidae is commonly referred to as the ant runner spiders. These spiders do not build a web for prey capture, but rather chase their prey down. I was lucky enough to catch a Castianeira longipalpa. They are extremely fast runners, and unlike most spiders, have a gait that appears more antlike than arachnid, and have been found living in association with carpenter ants (Howell and Jenkins 2004).
Another spider that resembles an ant more than it does an arachnid is Synemosyna formica, one of the ant-mimic jumping spiders. These spiders actually walk with their first pair of legs raised over their heads, to mimic the antenna of ants. They don’t jump, but can run faster than the formica ants they mimic, but are slower moving than most Salticidae (Gaddy and Kollath 2009).
In a more open grassy area I found a Larinia sp. orb weaver. The lines on the abdomen combined with the way the spider sits with the rear two pairs of legs straight back from the body, allow it to sit very well camouflaged in grasses (Howell and Jenkins 2004).
As I was preparing to leave a beetle that had been attracted to the lights on the building caught my eye. It was a Nicrophorus orbicollis (Roundneck Sexton Beetle). Nicrophorus beetles are a type of Carrion beetle, which excavate beneath the deceased body of small animals, causing the body to sink into the ground (Triplehorn and Johnson 2005). The beetle was not alone; it was carrying a load of Poecilochirus sp. mites. These mites are not hurting the beetle in anyway, but in fact are using the beetle as a form of transportation (Springett 1968), which is called phoresy. The beetles feed on decaying flesh, and the mites feed fly eggs and maggots that are feeding on decaying flesh. The mites have very limited means to travel between feeding areas, whereas the beetle can spread its wings and fly. So the mites climb aboard the beetle, and allow it to fly them to a new source of food.
In just the couple hours of looking I was able to create a list of over 25 species of spiders for the Bioblitz. I wish that I could have spent longer there, and I hope to make some time in the future to return to this site. Thanks to the staff of the Delaware County Preservation Parks for asking me to join in this event.
Work Cited
Bradley, R. A., and S. Buchanan. (2013). Common Spiders of North America. Berkeley, University of California Press.
Gaddy, L. L., and Rick Kollath. 2009. Spiders of the Carolinas. Duluth, Minnesota : Kollath-Stensaas Publishing.
Hansen, M.C. (1994) Ohio Shale Concretions. Ohio Geological Survey, GeoFacts, No. 4
Howell, W. Mike, and Ronald L. Jenkins. Spiders of the Eastern United States: A Photographic Guide. Pearson Education, 2004.
Springett, B. P. 1968. “Aspects of the Relationship Between Burying Beetles, Necrophorus Spp. and the Mite, Poecilochirus necrophori Vitz”. Journal of Animal Ecology. 37 (2): 417-424.
Triplehorn, Charles A., and Norman F. Johnson. Borror and DeLong’s Introduction to the Study of Insects. Belmont, CA: Thomson Brooks/Cole, 2005.
Weber, Larry. 2013. Spiders of the North Woods, 2nd Edition. Kollath-Stensaas Publishing
Spiders and More 