Monday, February 20, 2012

Scaphinotus ventricosus and S. striatopunctatus

The snail-eating ground beetles (genus Scaphinotus) are a diverse group in California (see my post for May 21 of last year for a note on S. subtilis). We have several in the Sierra, several more along the coast and a handful in other places. A month ago we were camping near Watsonville (in Santa Cruz County) and I found a small meadow near the campground with a few boards that had been left lying on the ground. I turned some of them over and found two different species, S. ventricosus (the smaller one below at around 13mm long).

and S. striatopunctatus (the larger one in the second picture at around 18mm long).

They were of noticeably different sizes at least in this particular place. Some of this may be a partitioning of their habitat (because of an immediate sympatry). The size range of both species normally overlap quite a bit (at least in museum series). Here, however, they were easy to tell apart based on size alone.


Jon Q said...

Two more eh?? These California Beetles are making me jealous haha. Looking forward to april!!

Sam Wells said...

Indeed Jon, the bugs are starting to move!