Sunday, December 4, 2011

Beetles aplenty (Ceroglossus)

Right under just about everyones' noses are loads of pretty and interesting beetles just waiting to be found (and photographed). Many of the coolest are members of the family Carabidae, the ground-beetles, into which the family Cicindelidae, the tiger beetles, has been absorbed. But since I have written a bit about the tiger beetles (see here) on to other carabids!

Ceroglossus sp., Chiloe Island, Dec 3, 2011
Ground beetles are a rather diverse family with herbivorous, carnivorous and omnivorous members, but we'll focus on the carnivores here, as many of them are big and flashy. As I said earlier, they are common and widespread, but rarely seen. In eastern North America we have a few genera of flashy beetles - Calosoma scrutator being the most widespread large flashy species, see here for pictures. That and others, including the Callisthenes calidus pictured below are caterpillar hunters. While most ground beetles stay are true to their name, these species often climb trees in search of prey - however, they can still move quite rapidly on the ground, I have read that some carabids are among the fastest animals for their size with long thin legs well suited to the purpose.

Callisthenes calidus, Nantucket, MA
These species, being big, juicy beetles, are commonly targeted by birds and mammals and thus have evolved an interesting defensive strategy. They emit a really foul-smelling (and tasting) fluid which causes them immediately to be spat out (theoretically). I can atest, having once accidently gotten a small carabid in my mouth while biking - the resulting taste was the longest-lasting, and most disgusting thing I have ever tasted. But some species still eat them; a scientist here told me that a Chucao followed them on their pitfall lines and would eat the Ceroglossus that they released. 

Ceroglossus sp. (magellanicus?), Nov, 2011
The Ceroglossus are much loved here and one of the symbols of the native forests (which they don't necessarily need - they exist in Eucalyptus groves as well) along with the Monito, the Rayadito and the Pudu. I catch most of them walking along paths as they try to run out of sight, but I was amazed that in one of my small pitfalls here to catch 3 (of the first species) in one night. 

Notice the little hairs (setae) in a row along the inside edge of the wing
covers (elytra). 
When I searched for more info, I was able to find one site (here) entirely devoted to the genus (which is entirely South American), which seemed to be a good resource, but it was in French. Therefore, I was not able to properly ID the species I caught.

1 comment:

  1. I love those beetles. Actually, I study them. They are among the coolest beetles in the temperate forests of Chile.