26 July 2011

Davy Crockett Collecting Trip

I recently made a short collecting trip to Davy Crockett National Forest. The weather was not ideal it rained intermittently and when the rain stopped the moon was out in full force. None the less the black light did bring in a few interesting things including a couple of beautiful extra large Strategus. However, some of the little things were just as amazing like this small dytiscidae belonging to the genus Thermonectus.
Looking at this guy under the scope reminded me of the evolutionary novelty that beetles exhibit that has always been a source of wonder to me. The protarsi of some male Dytiscidae like this one have an amazing array of suction cups that increase the gripping power of the beetles front legs. Most books say that these are used to allow the male to grasp the female during mating. This seems like a plausible explanation though I could not find any publication of an experiment actually testing this idea. Whether it is important in mating or in prey manipulation it is none the less an amazing structure to evolve in an organic form.

A lot of other beetles with aquatic affinities showed up like this Limnichidae with really cool pronotal excavations for the antenna. The species on this one is Physemus minutus. Thanks to the bug guide users who helped me on that identification!
This close up shows a slightly better angle and enlargement for both the excavation that receives the antenna and the setae filled pit in front of the eye.
Another Limnichidae that I have not yet identified has an amazing suit of iridescent bronze and silver setae.
The carabid Tetragonoderus (peronoscelis) latipennis also showed up at the light. This beetle behaves much like a nocturnal tiger beetle often hunting along sandy shores at night. During the day they normally are hidden in leaf litter.

Lots of other interesting but small guys came to the light so if I cant get some IDs I'll have more to post.

1 comment:

  1. Great post! Dytisids always fascinated me.