Tiger beetles are apparently very difficult to catch, although one would not know it when seeing the great number of tiger beetles in the museum’s collection. A quick survey revealed the Museum has over 500 pinned specimens in three genera; Cicindela, Ellipsoptera and Amblycheila. After cataloguing a couple hundred tiger beetles, I became curious about their biology, and did some research.
Tiger beetles are found all over the world and there have been over 2600 named thus far. North America has over 100 species. Tiger beetles are carnivores, and adults have long legs and prominent mouthparts to enable them to catch and consume other insects and spiders. Even though they have large eyes, they run so fast that vision is not sufficient to help them avoid obstacles. Instead, they hold their antennae out in front of them to monitor the landscape they are running through. Periodically, they need to stop to relocate their prey.
You can see a tiger beetle in the Carberry Sand Hills diorama at the Museum. Many of these beetles do live on the ground in dry or sandy areas, and in Manitoba this is where you may be able to see them. But be careful! They can give you quite a pinch with their sharp mandibles if you try to pick one up. Since they are carnivores, they do tend to have, for their body size, rather large mouthparts.
The larvae are also predatory, but rather than chasing and capturing prey, use a ‘sit and wait’ strategy. Juveniles dig a vertical burrow and then patiently watch the entrance for unwary small arthropods to venture too close. Unlike the larval stage of many other insects, tiger beetle larvae have well-developed eyes and good vision. They swiftly pierce prey with their sharp mandibles, and pull it down into their burrow to eat. Juveniles also have hooks lower down on their dorsal side to enable them to anchor themselves in their burrow and avoid being pulled out by unruly prey.
Many of the adult tiger beetles have distinctive markings on their elytra (hardened forewings) that can be used for identification. Some species are brown with yellowish-beige patterns, but others can be quite colorful. Iridescent blues, greens and reds are common.
In my readings I came upon an extremely enthusiastic piece, written by an American entomologist Ted C. MacRae. His blog described his efforts to photograph the spectacularly colored tiger beetle, Cicindelapulchra, during a fall field trip to a site in southwestern South Dakota. He called his article “North America’s most beautiful tiger beetle”, which I assumed at first was due to his obvious fascination with tiger beetles. Later I looked up this beetle’s common name and found it in fact to be the “Beautiful Tiger Beetle”! Only a beetle lover could have named it thus…..
Karen Sereda, Natural History Cataloguer