Friday, June 5, 2009

Some tough beetles

I’ve got tiger beetles on my mind. In the course of preparing a general interest article on these fascinating killers, I’ve been studying up and reminiscing on the various tigers that I’ve seen in the wild. Following are a few photos of these interesting insects, and I am grateful to John Pogacnik and Warren Uxley for graciously providing their work for others to see. Ditto the aptly named tigerbeetlefreak who has some fantastic stuff on Flickr.

The most common and wide-ranging of the twenty species of tiger beetles recorded in Ohio: Six-spotted Tiger Beetle, Cicindela sexgutatta. This incredible photo by John Pogacnik shows several of the features that characterize tiger beetles, and make them such formidable predators. Their mandibles are long and scimitar-like, and rimmed with jagged teeth. Once prey is captured, the beetle makes mincemeat of it quickly. Note the proportionately very long legs. This enables Ferrari-like acceleration, and a top speed that can allegedly approach five miles per hour for some species. For a ½ inch long insect, that is stupefying velocity, and some authorities believe tiger beetles to be the fastest land animals, if their size is taken into account.

Dorsal, or top view, of the Six-spotted Tiger Beetle courtesy Warren Uxley. You may have seen this one. It frequents shady woodland paths, and is often conspicuous as a brilliant emerald glimmer before rapidly darting off. Sneak up for a good look, and you’ll perhaps be able to see the six beige spots edging the carapace, or upper shell, that give it its name.

One of the rarest of the rare among Ohio’s tiger beetles, a Claybank Tiger Beetle, Cicindela limbalis. This photo from John Pogacnik, who took it along the few – maybe only - northeastern Ohio streams where they are still known to exist. The mandibles as seen in this shot are impressive indeed, and the curtains would quickly fall for anything unfortunate enough to get seized by this brute. Note too the massive bulging eyes. The better to see you with, my little pretty.

Even the larvae of tiger beetles are daunting in the extreme. This photo comes from the repertoire of tigerbeetlefreak, via Flickr. It shows the larva of a White-cloaked Tiger Beetle, Cicindela togata (taken in Nebraska), at the mouth of its burrow, waiting to pounce. These grubs dig long tubular tunnels – in some species up to several feet deep – and then sit motionless at the entrance. A special hooklike appendage helps them to prop stiffly against the tunnel walls, and probably also serves to help them from being drug from the tunnel should they seize something too large and powerful. When an unsuspecting prey item happens by – might be anything from a caterpillar to a bee – this horrifying grub of action lunges out and snares it with mandibles similar to the adults. The victim is then pulled to the bottom of the tunnel and consumed. What a great way to go.

The aptly named Festive Tiger Beetle, Cicindela scutellaris. I captured this one earlier this spring and wrote about them HERE. This macro shot shows a typical substrate favored by tiger beetles: loose sand.

Finally, another amazing John Pogacnik shot, taken in the sands of the Oak Openings west of Toledo. This is a Ghost Tiger Beetle, Cicindela lepida, one of numerous strange critters that inhabit sandy Oak Openings habitats. This is another rarity, known from only four Ohio counties.

Although a bit of effort is required, tiger beetles are fascinating to observe and if one is patient, they will often resume going about their business of hunting and killing in close proximity. They also serve as great environmental barometers, and are worthy of monitoring. As top-end predators, these beetles are akin to Peregrine Falcons in the bird world, and may be among the first organisms to vanish if things start to go amiss with the ecological chain.


Tom said...

Jim, very nice, I want to second how nice John's photos of these tiger beetles are. Great post.


Jared said...

Is there anything John isn't an expert on or unable to photograph?

Jenn Jilks said...

I'm looking for help IDing some of these bugs. I cannot find my bug book!
I can find my tree book, and my bird book, and my swamp flora book...
Any suggestions?! You seem to know the experts!

Jim McCormac said...

John is a wizard with that Panasonic FZ-50 camera, no doubt. Jenn, your best bet is to get a copy of Kenn Kaufman's Insects of North America guide. It is easily the best thing going to start to figure out bugs.


Heather said...

A very interesting post, if not a little bit scary! Wow, those beetle mandibles are ferocious! I found, photographed and identified one of those green tiger beetles on our property earlier this spring. Funny thing is, once I found out it was a Tiger Beetle, I thought I was done. I had no idea there were so many different species of this bug!

dAwN said...

oh my super macro shots! Thanks to your guest photographers..
great information as always!