|10/31/2017 1:09:00 PM|
The tiger beetle
One of fastest and most aggressive beetles crawling, running, and chasing other invertebrates on the surface of our home planet can be found on the Oregon Coast: the tiger beetle. With apologies to my good pal, great artist and musician Dennis McGregor, I stuck a head-on photo of an adult tiger beetle on the head of the tiger, and another crawling up its body, like he likes to do.
|The author attempted to create a composite photo in imitation of Dennis McGregor’s “You Stole My Name” art. photo by Jim Anderson|
The only similarities or associations tiger beetles have with tigers is the manner in which the beetles capture their prey and the entomologist who thought they acted and looked like their namesake. I doubt very much if you'd ever find a tiger beetle sitting on a tiger's head in real life, but because of Dennis' influence on my imagination, I put it there.
The hunting methods of mammal tiger and insect tiger are very similar. While tigers are mammals, born into the world just like you and me, the tiger beetle begins life as an external egg, hatches into a larvae, then proceeds to a pupae, then, after the miracle of metamorphosis, it then emerges as an adult.
In the very early stage of life, mammals live - and grow - utilizing the nutrients in their mothers' blood. The tiger beetle, on the other hand, grows while it's in the larval stage, and even then, it's a supreme killer of other, smaller invertebrates. As adults, they have another trait that's in their favor: they are known as the fastest terrestrial insect on this grand old planet Earth.
They display an uncommon method of pursuing their prey, in that they alternatively dash quickly toward their victim, then stop, then dash after it again. This may be because while making those sudden sprints, the beetle's moving too fast for its visual system to accurately process in real time. Maybe it's like me as I get older, having to stop and say to myself, "Now, where was I headed...?"
Tiger beetles have another trait that may also be associated with their speedy, sprint-stop-sprint-stop method of pursuit. To avoid running into things, they hold their long, rigid antennae directly in front of them to mechanically sense what's coming, head-on.
In 1996, scientists in the Netherlands tested two species of Australian tiger beetle, Cicindels eburmeola and C. hudsoni. Both have "vestigial" wings, so they cannot fly, but make up for it with running skills. They were clocked at 5.6 mph, capable of covering eight feet in one second.
Tiger beetles have large, bulging eyes, which gives them acute, wide-angle vision. Their long, slender legs and powerful muscles in the thorax provide them with their unusual speed. They also possess large, curved mandibles with which they grasp and crush their prey. (Sounds like the canines of a tiger, doesn't it?)
While most species are diurnal (day-moving), four genera are nocturnal, and most tiger beetles are brightly colored, while a few genera found living primarily in the dry regions of southern Africa are black.
While there are many instances of adult tiger beetles glomming onto human appendages, there are no records of the larvae of tiger beetles attacking humans. The larvae live in cylindrical burrows as much as three feet deep. They're large-headed grubs with a large, muscular humpback, which they use to flip backwards, to capturing insects that wander over the surface nearby.
They are also considered a good indicator species, and have been used in ecological studies on biodiversity health. That is, if they are found in their normal numbers in habitat where they were once found it would suggest the habitat for all species in that niche are in good condition.
The next time you head for North Bend or Coos Bay for a day on the beach, take a look in the sand dunes among the grasses and other vegetation and you'll likely meet up with Oregon's tiger beetles. If you don't, please call me and we'll find out why.
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