Friday, May 30, 2014

A caterpillar in the bonnet

The bluebonnets attracted many more visitors than just bees this spring.  Among these other visitors were caterpillars – which came to feed on, rather than from, the flowers.

A caterpillar feeding on the buds of a Texas lupine (Lupinus texensis).
However, the flowers were not the most enticing part of the bluebonnets for herbivores.  Soon after the seeds pods began maturing, they started to become riddled with holes.  Meanwhile, the seeds that should have been developing inside were damaged or even completely missing.

Texas lupine seed pods after a seed predator attack.
The first insect that I found in the vicinity of the holes was a lady beetle. 

A seven-spotted lady beetle (Coccinella septempunctata) by a freshly chewed hole in a Texas lupine seed pod.
Yet, nearly all lady beetles, including the one pictured here, are primarily predators of other insects, not of seeds.  Therefore, it seemed unlikely that the lady beetle was the culprit.  Then, what was making all the holes?  To be continued…

Wednesday, May 28, 2014

Camera shy

A metallic fly on a sunlit leaf should make an attractive picture.  Yet getting such a picture poses a serious challenge.  It is not that the flies are rare, since I often come across gleaming blue, green, and even gold flies perched in the sun.  It is not that they fly away either.  The flies sit still as I line up my camera and are still sitting on the leaves once the pictures have been taken.  However, the flies do not appear in the pictures themselves.

A leaf where a fly had been sitting a moment before.  If you look closely, you can find two of the fly's legs.
In between the time that I press the shutter button and the time that the picture is taken, the flies reliably launch themselves off their leaves, only to land again the next moment.  This amazing disappearing act is possible because flies have extremely fast reaction times.  As soon as the camera begins to flash, the targeted fly initiates its evasive action.  Nevertheless, the flies are not impossible to catch on camera (even when continuing to use the flash).  With some experimentation, it is even possible to capture them in midair.

After many tries, I was also able to take a picture of the fly sitting on the leaf.  Perhaps I had momentarily worn the fly down or the angle of the shot had caught the fly by surprise.

A sneak attack from the rear finally succeeds in capturing the longlegged fly (Dolichopodidae, subfamily Sciapodinae).
 Either way, the fly soon returned to its shy ways.

Can you find the fly's shadow?
Explore some more: Why Flies Are So Hard to Swat

Wednesday, May 21, 2014

Where the wild genes are

This spring, I taught a course on Animal Behavior.  Consequently, most of my enthusiasm for sharing the intricacies of the interactions among animals (and other organisms) was channeled towards the class rather than the blog.  During the course, I was able to learn many new things myself thanks to the hard work of my students.  Therefore, I encouraged the students to share their writing assignments on their class blog, "Where the Wild Genes Are".  Their posts on their own natural history observations, their analyses of the communication of science, and their contributions to Wikipedia articles will continue to be published every couple of days for the next few weeks.  I encourage you to follow their blog and learn about a wide variety of animals, behaviors, and concepts in behavioral ecology.

A monarch butterfly (Danaus plexippus) feeding on a crimson clover (Trifolium incarnatum).
Natural Current Events should also be getting back to a more regular schedule in the near future.   Although I did less posting this semester, teaching didn't mean that I stopped photographing.  If you want to see more pictures of Houston spring flowers, you can find a selection in the album here.