In a recent post, I provided the first ever glimpse of the previously unknown larva of Cylindera celeripes, or swift tiger beetle. This little-known flightless species is among the tiniest in North America (adults measure only 8 or 9 mm in length), and so far nobody has succeeded in rearing the species in the lab, or even finding its larva. As the photographs in that post showed, I am reasonably close to accomplishing that first goal, having successfully obtained a number of eggs from field-collected adults placed in a terrarium of native soil. I fed the subsequent larvae a diet of small rootworm larvae and Lygus nymphs before putting them to sleep for the winter in a cold incubator, and the larvae resumed activity when I pulled them out of the incubator 2 months ago. Since then, they have feasted heavily on small noctuid larvae that we rear in our lab, and now most of the dozen or so larvae have sealed their burrows – I presume for pupation before (hopefully) emerging as adults in the next few weeks.
There is more to the story, however. I had brought the adults back home in June 2009 from a population I found at Alabaster Caverns State Park in northwestern Oklahoma. This was a reasonably robust population – news enough for a species that has not been seen in good numbers for many years now, and my discovery of equally healthy populations at several other locations in the general area gives new hope for the long-term prospects of a species that some regard as a potential candidate for listing as an endangered species. It also gave me hope that I might be able to find the larva were I to return to the area in the fall. I also had a hunch that Cicindela pulchra (beautiful tiger beetle) could be found in the area, based on some very large larvae I found during that June trip, so in early October I made a quick return to northwestern Oklahoma to search for these two species. While it was too cold and wet to have any hope of finding Cicindela pulchra adults (I still think the species is there), it did not prevent me from realizing my other goal. May I present one of the first ever field-collected larvae of Cylindera celeripes!
I found the larvae at Alabaster Caverns where I had found the adults earlier in June, and although the larval burrows were very small (only 2 to 3 mm in diameter), I knew what they were immediately when I saw them. As I had observed for the adults, burrows tended to be near the edges of barren patches of soil in proximity to vegetation and not out in the middle of the barren areas. This makes sense, considering where it would be more likely for prey to be encountered. Because the weather was cold and gray, I didn’t see (or expect to see) larvae actively sitting at the tops of their burrows, so I began “fishing” to see if I could yank a few from their burrows. I fished quite a few burrows for the first half hour or so, but none of my attempts were successful. I began wondering if the larvae were even active at all or if they had already entered hibernation for the upcoming winter. While I was fishing, I noticed that the burrows all seemed rather shallow – only about 6” or so (most tiger beetles, having larger larvae, dig burrows that are much deeper). This gave me an idea. I went back to the truck and retrieved a small spade that I carry in case… well, I’d never actually used it before. Anyway, I inserted a grass stem into a burrow and sunk the spade into the ground right next to it, making sure I got the spade at least as deep as the grass blade. I then removed the spade and sunk it into the ground on the other side of the burrow, then pried until the entire chunk of soil came up intact. With the bottom of the soil chunk exposed, I used my knife to carefully remove slivers of soil until I found the end of the grass stem that I had inserted into the burrow. Carefully removing the soil in this area revealed the larva in a side chamber at the bottom of the burrow. Success! I took many photos of that larva right then and there, and over the next hour or so collected several more larvae, all but one of which I presumed were 3rd instars. I packed each larva in its own small vial of native soil for the trip home, and although I have been attempting to rear them out for confirmation of their identity, there is little doubt that they do indeed represent this species.
The photographs I’m showing here are not those first field photographs that I took when I first discovered the larvae. Looking at those photographs after I returned home, I was dissatisfied with the amount of soil and debris that covered the larvae – especially their grotesquely unique head and pronotum. Instead, I removed one of the larvae from its rearing tube and gave it a “bath” – brushing it with a fine camel-hair brush in a shallow dish of water – to clean it up for the photographs shown here. After the photo shoot, I sacrificed this larva for the collection – it will be the basis for a formal description of the larva of this species (along with examples of the 1st and 2nd instars that I had sacrificed from my rearing, not yet confident that I would succeed in getting any of the others to 3rd instar). The only thing I am waiting on before preparing that description is to see whether I actually succeed in rearing this species from egg to adult – stay tuned!
Photo Details: Canon 50D (ISO 100, 1/250 sec, f/13-16). Canon MP-E 65mm 1-5X macro lens, MT-24EX flash (1/8 power) w/ Sto-Fen diffusers. Typical post-processing (levels, unsharp mask).
Copyright © Ted C. MacRae 2010
22 thoughts on “Cylindera celeripes Larva Revealed”
Nice pictures Ted, especially the last freshly-scrubbed head shot. It reminds me of an infant Triceratops.
Looking forward to seeing the freshly emerged adults!
Thanks, Adrian. “Infant Triceratops” – I can see it!
A very interesting story. It’s always exciting to discover things that people have not seen before, especially when the discovery is made based on your own personal research and insight into the subject. That’s an amazing larva.
Thank you, Steve. Yes, these are among the most bizarre insect larvae around. Those four eyes…!
Excellent! I’m always surprised at how little is known about the immatures stages of insects (at least those that aren’t pests) and especially of beetles. Great to see someone putting in the time and effort to find out.
Exciting! Good luck with the metamorphosis!
Hi Margarethe – I’m checking that terrarium daily now looking for any sign of a scamper!
Thanks, Dave. I can imagine how little is known about mite immatures! All it takes to find out is a little passion. 🙂
These critters do not have pretty faces, but I still can’t stop myself from looking!
Any ideas what the four eyes do? 360-deg. vision, perhaps?
Maybe not pretty, but I regard them as grotesquely beautiful. Yes, they certainly make you want to stare. Tiger beetle larvae have acute focusing abilities and are able to distinguish both the size and distance of moving objects – I’m sure the four eyes (six in some species) have a lot to do with conferring such capabilities.
Tiger beetle larval vision has been studied pretty deeply. Here are a few papers, starting with an interesting review:
Click to access f1ff63ff2b46ae08f8779fcf9bda6c14c829.pdf
Good show, Ted. Lots of people would probably describe tiger beetle larvae as bizarre, but they are fascinating to watch.
If you go to the Albaster site this early summer, and you have time, stop at the south end of the bridge over the
Cimarron River, and hike down to the river if the sand bars are visible. I got C. repanda, C. hirticollis shelfordi,
C. tranquebrica, C. togata globicollis, and C. nevadica knausi there in June, 07. Check the bars and the sandy bank of the river. Most plentiful were the hirticollis. I expected C. curpescens or macra there but did not see any of those.
Thank you, Charlie. I saw those sand bars and thought they looked like a good place to look for the sand/moisture loving species. That whole part of Oklahoma seems to be a real tiger beetle hot spot – in addition to the C. celeripes and D. pruinina spots I found (which may yet harbor C. pulchra) and the sand bars you note, I found eight species of tigers at nearby Salt Plains National Wildlife Refuge, including the species you mention (except C. hirticollis shelfordi) and also C. fulgida, H. circumpicta johnsonii, and C. formosa. I’d even be willing to bet that Amblycheila cylindriformis and C. obsoleta are in the area as well. It would be easy to see if E. cuprascens or E. macra are there by setting up blacklights along the river at night.
I can’t wait to go back!
Congratulations Ted! Such a fascinating world you travel, and to bring light and knowledge forth regarding the mysteries of nature is quite exciting. 🙂
Thank you, Beau. It’s not always so fascinating or significant, but making discoveries like this once in awhile makes it all worth it!
Is it easy getting the necessary permits to remove things from these Oklahoma State Parks? They are usually fairly strict. Next time, will you slip me a little honey locust sapling from Boiling Springs?
When is the best time to see tiger beetles in Harper and Woodward County? I am there all the time – but never in summer, is that the problem? I’ve been inspired by Doug Taron for three years now and have yet to find a tiger beetle in Oklahoma. Doug – are you reading this – get yourself to Oklahoma — look at all these species. I’ll pick you up at the airport and we’ll stay at Sue Selman’s.
Have you been to Selman Ranch in Harper County yet? Sue Selman is incredible — she runs a Sustainable Oklahoma ranch B&B there and is starting to notice lots of tiger beetles on her property. I just had Doug ID one for me last month (a pic she took). The Lesser Prairie Chicken rescue efforts are commandeered from the Selman Ranch. You should check it out — and give a Sue a call. She is instrumental in saving the prairies up there in that part of Oklahoma.
I had great cooperation from the Park Historian and Park Naturalist during my two visits – each gave me permission on the spot. I showed them what I found and told them how significant it was, they seemed pleased to know that there was something special about “their” park.
You should be able to find tiger beetles as soon as the weather warms in March until the weather turns in October. Habitat is important, as most species are quite specific regarding the soil type they prefer. In dry sandy areas you should have no problem finding Cicindela formosa (big and purple with bold white markings) and C. scutellaris (smaller, blue pronotum and red elytra) during spring and fall. Other species are out during the summer. Go to the Sandpiper Trail at Salt Plains NWR and you should have no problem finding tiger beetles on the barren salt flats near the water.
Pingback: Alan S. Hochman Photography
Images and info are superb. I’m marking this for use by my Field Biology students!
Thank, Dave – glad you liked it. I “discovered” a few more larvae on this past weekend’s trip that I’ll be writing about in future posts.
For what it’s worth…found this larvae in Crawford County, KS this week. Identified it through your website.
Hi Douglas – the larva of this species has not been described yet, so the only way to confirm the identity is by associating with adults. Have you collected adults at this site? If so that would be a significant record, and I would appreciate more information.