This is the fourth in a series of “Collecting Trip iReports”—so named because I’ve illustrated them exclusively with iPhone photographs. As I’ve mentioned in previous articles in this series (2013 Oklahoma, 2013 Great Basin, and 2014 Great Plains), I tend to favor my iPhone camera for general photography—i.e., habitats, landscapes, miscellaneous subjects, etc.—during collecting trips and save my full-sized dSLR camera only for those subjects that I want high-quality macro photographs of. iPhones are not only small, handy, and quick but also capable (within reason) of quite good photographs (see this post for tips on making the most of the iPhone camera’s capabilities). This keeps the amount of time that I need to spend taking photos at a minimum, thus allowing more time for the trip’s intended purpose—collecting! Those photos form the basis of this overall trip synopsis, while photos taken with the ‘real’ camera will be featured in future posts on individual subjects.
Last year during late September and early October I travelled to eastern and central Texas. This trip was all about fall tiger beetles, in particular certain subspecies of the Festive Tiger Beetle (Cicindela scutellaris) and Big Sand Tiger Beetle (Cicindela formosa) found in that area that I had not yet seen. I enjoy all collecting trips, but fall tiger beetle trips are among the most enjoyable of all—cooler temperature, a changing landscape, and charismatic subjects that are both fun and challenging to find and photograph. This trip was no different, with spectacular weather during the entire week and, for the most part, great success in finding the species/subspecies that I was after. At this point I’d like to acknowledge the help of several people—David Hermann (Ft. Worth, Texas), David Brzoska (Naples, Florida), and Steve Spomer (Lincoln, Nebraska), who generously provided information on species and localities. My success at finding these beetles was due in large part to the information they provided.
Day 1 – Cobb Hollow
After driving 700 miles from my home near St. Louis, I arrived at the first stop of trip—Cobb Hollow in north-central Texas. This small creek lined with deep, dry sand is close to Forestburg (Montegue County)—the type locality of Cicindela scutellaris flavoviridis, a beautiful, all-green subspecies with the elytra suffused golden-yellow. The habitat looked very promising from the start, and it wasn’t long before I found the first tiger beetle of the trip—a gorgeous, red nominate Big Sand Tiger Beetle (Cicindela formosa formosa). Not long after that I found the first Cicindela scutellaris flavoviridis, and over the next few hours I would find a total of nine individuals. Despite the extensive habitat along the creek the beetles were quite localized, occurring primarily in two dry sand areas within a mile west of the bridge. This spot is actually near the northern limit of the subspecies’ distribution, and several of the individuals showed varying influence from nominate scutellaris with the elytra tending to be more red than yellow-green. There was a diversity of other tiger beetles here as well—C. formosa formosa was the only one that was common, but I did find also a few individuals each of Tetracha carolina, Cicindelidia punctulata, Cicindela splendida, and C. repanda. A very cool place.
Day 2 – Stalking the Limestone Tiger Beetle
Today was all about looking for the Limestone Tiger Beetle, Cicindelidia politula. I have collected this species previously at several sites in Erath and Somervell Counties, Texas (west of Ft. Worth) and featured photographs from that trip. However, since I would be passing through the area on my way south I decided to spend a day looking for it again and, hopefully, collecting a few more specimens. Cicindelidia politula is related to the much more common and widespread Punctured Tiger Beetle, C. punctulata, but is shiny blue-black with the elytral markings absent or limited to the apices and the abdomen red. I visited several localities—two new ones for me in Erath County and another I had visited previously in Somervell County, with habitats that ranged from rocky clay to white limestone exposures along roadsides and even limestone gravel.
I found a fair number of individuals at the first site (1.7 mi SW Bluff Dale, Jct US-377 & FM-1188), which had a finely ground limestone substrate. Most of the individuals were flushed from the base of clumps of bunch grass and captured when they landed in more exposed situations.
The beetle had also been reported along the roadsides at the second location (0.4 mi E Jct FM-2481 on CR-539), but the only individual I saw here was on a very coarse crushed limestone 2-track leading off of the main road.
The species was most numerous at the third site in Somervell County (3.4 mi SE Jct US-67 on CR-2013). I collected ten individuals and saw probably that many more on white limestone exposures along the roadside and along a dirt road cut along the base of the hill to the NE side of the highway. Most of the beetles in the latter area were seen along the scraped dirt road (at left in 2nd photo below), although presumably the beetles also utilized the undisturbed, surrounding habitat.
Catching the beetles at this last locality was challenging—the adults are fast and flighty, and the rough, rocky habitat made it difficult to clamp the net over the beetle and pounce on top of the rim before they were able to find a gap and escape. With practice I found my catch efficiency increased a little bit if I slowly approached the beetle and then made an assertive swing with the net right when the beetle began to fly—the trick is learning how to tell when they are ready to fly (and “assertive” is the key word!). Tiger Beetle Stalker; however, does not quit!
Day 3 (Part 1) – Pedernales Fall State Park
This was another locality where Cicindela scutellaris flavoviridis had been recorded. I came here to find this subspecies even though I had seen it two days previously at Cobb Hollow, because that latter population showed some slight intergradation of characters from nominate C. scutellaris and I wanted to get field photographs of a “pure” population. I was pretty excited when I saw extensive dry sand habitat lining the upper bank area along the Perdenales River; however, I found no tiger beetles of any kind after extensive searching through that habitat. I did note the area seemed dry and reasoned that perhaps timely rains had not yet triggered emergence of C. scutellaris, C. formosa, and other sand-loving fall tiger beetles. I did find a small area of wet sand right along the water’s edge where three species of Cicindelidia could be seen: C. ocellata rectilatera, C. trifasciata ascendens, and C. punctulata. I’ve photographed all of these species before, so I didn’t try to spend any time doing so here. However, combined with the species seen the previous two days, this made a total of ten species seen on the trip so far. Although I didn’t find the beetle I was looking for, I marveled at the beauty of the area, especially the Pedernales River with its hard, conglomerate bedrock and mini shut-ins and spent quite a bit of time here taking photographs.
Day 3 (Part 2) – Lick Creek Park
Another of the Festive Tiger Beetle subspecies that I wanted to look for was Cicindela scutellaris rugata. I had several localities from which this solid blue-green subspecies has been recorded, and this site was the nearest of those that I planned to visit. The drive from Pedernales State Park was longer than I anticipated, so I didn’t get to this spot until close to 6 p.m. At first I worried that I wouldn’t have enough time to even find suitable habitat, but that was no problem as I quickly found the Post Oak Trail and its perfect open, post oak woodland with deep sand substrate. By all accounts the beetles should have been all over the trail but they weren’t. As with the previous site, the area was quite dry as evidenced by the wilted plants along the trail side, and I also note that the previous record from here was on Oct. 23rd—more than three weeks later. Despite the fact that I didn’t find any tiger beetles, I did see a young timber rattle snake (Crotalus horridus) crossing the trail late in the hike—I took a quick shot with the iPhone (see below) and then broke out the big camera and was able fire off a few shots before it left the trail and headed for cover. (Several people walking the trail came upon us, and they were all—happily—more than willing to oblige my requests to stay away until I was finished.)
Day 4 – East Texas cemeteries
Cemeteries are often great places to look for tiger beetles because they tend to be located on parcels of land with low agricultural value that were donated by landowners to local churches. Older cemeteries especially tend not to be highly maintained and, thus, offer excellent habitat for tiger beetles. My goals for this day were Cicindela scutellaris rugata and the gorgeous Cicindela formosa pigmentosignata. I had records of both from a couple of cemeteries in eastern Texas (Sand Flat Pioneer Cemetery in Henderson and Morris Chapel Cemetery in Van Zandt Counties) and found good numbers of both along sandy 2-tracks and sparsely to moderately vegetated sand exposures in and around the cemetery grounds. I don’t have any iPhone photographs to share of either of these species, but I did spent a lot of time with the big camera and got a number of photos of each that I am quite pleased with—I’ll share those in future posts. The cemeteries themselves were haunting and poignant, with some headstones dating back to the late 1800s.
At Morris Chapel Cemetery I found C. formosa pigmentosignata and C. scutellaris rugata on sparsely vegetated deep dry sand 2-track north of the cemetery. I did also manage to get field photos of the former before it got too hot and they became too active. There were also a few of the latter in the open sandy ground just outside the northwestern edge of the cemetery. As with Sand Flat Pioneer Cemetery, I spent a bit of time in the cemetery proper to look at the headstones—the oldest headstone also being the most poignant; a one and a half-year old boy who died in 1881.
After finishing up at Morris Chapel Cemetery I returned to Sand Flat Cemetery to see if I could get more field photographs before the beetles bedded down for the night. The sun was still up when I arrived a little before 6 p.m., but the shadows were long and no beetles were seen. Not one to waste an opportunity, I broke out the big camera anyway and started photographing a large species of bee fly (family Bombyliidae) that was perching on the ground and on the tips of plains snakecotton (Froelichia floridana).
Day 5 (Part 1) – Cowtown Bowman Archery Club
With both specimens and good field photos of Cicindela scutellaris rugata and C. formosa pigmentosignata in hand, I returned my attention to C. scutellaris flavoviridis. Again, I did already have specimens in hand from Cobb Hollow, but most of them showed some degree of intergradation with nominate C. scutellaris and I was hoping to see some “pure” individuals. Failing to find it at the more southerly locations (Pedernales State Park and Lick Creek Park), I had one more location in Tarrant County where the subspecies had been recorded—a sand borrow pit near the entrance of Cowtown Bowman Archery Club. Once again I searched the area thoroughly for a couple of hours during mid-morning but did not see the subspecies or any other tiger beetles. Conditions were overcast and cool (72°F), but I do not think this explains the absence of adults. Rather, I think I was on the early side of the season and they just hadn’t started emerging at this site.
While I was at the site I found several tiger beetle larval burrows in a moderately vegetated area near the deeper sand deposits that were occupied by Tetracha carolina, so I used the “stab” or “ambush” method to collect several 3rd instars for an attempt at rearing. For those of you who are not familiar with this technique, a knife is set at a 45° angle with the tip in the soil about 1″ from the edge of the burrow. Then you wait, sometimes for quite a while, until the larva reappears at the top of the burrow and STAB the knife assertively into the soil to block the larva from retreating. The larvae are extremely wary with excellent vision and will usually drop back down immediately when they see you, so you have to be ready and act quickly. Once the retreat is blocked, a simple twist of the knife to expose the larva is all that is needed. I prepared larval habitats by placing native soil with as intact a top layer as possible in plastic critter carriers, made a starter hole for each larva with a pencil, dropped each larva into one of the holes, and then pushed the soil to seal the burrow entrance. This prevents the larvae from crawling right back out of the starter burrow, which can result in them encountering and fighting each other. The larvae will eventually reopen the burrow entrance, but after being sealed inside for a while they usually accept the burrow and further modify it to suit their needs.
Larval burrows (lower left) can be recognized by their clean, almost perfectly round, beveled edge. The presence of fresh soil diggings cast to one side (upper right) indicates the burrow is occupied by an active larva.
Using the “stab” or “ambush” method to collect larvae. One must have patience to successfully use this method.
Day 5 (Part 2) – Cobb Hollow (epilogue)
Although I had found Cicindela scutellaris flavoviridis at this site on the first day of the trip, I had not taken any field photographs in hopes of finding a more “pure” population at one of the more southerly locations. That did not happen, so I returned to Cobb Hollow on this last day in the field to get field photographs from the population there. Temperatures were a bit cooler (mid-70s) and cloud cover was variable, actually sprinkling when I arrived mid-afternoon but eventually clearing. This seemed to have no detrimental effect on adult presence, and it may have actually helped as I was able to photograph the very first individual that I found to my heart’s content. I collected that individual and the next three that I saw by hand and found two more over the next hour—all on the same deep, dry sand bars west of the bridge where I had seen them previously. Curiously, Cicindela formosa was strangely absent from these same areas where they had been so numerous a few days earlier.
On the east side of the bridge I collected two more Tetracha carolina in the same moderately vegetated sandy clay spot as last time, then went on to the furthest dry sand bar where I found and photographed (but did not collect) a single C. formosa (only one shot before it took off). I also found a female green lynx spider (Peucetia viridans) sitting on her egg mass and got some nice macro photos as well as this iPhone shot (talk about a face only a mother could love!).
I hope you’ve enjoyed this collecting trip iReport. Stay tuned for true macro photographs of the tiger beetles and other insects/arthropods that I photographed on this trip in more subject-specific posts. You are also welcome to leave feedback in the comments below.
© Ted C. MacRae 2016