Tuesday, October 3, 2017
The WOLF class field trip to Bull Creek last week had us talking about riparian tree identification and why trees are important. As fascinating as I am sure the 5th graders found our insights, they couldn't compete with grasshoppers. One hop and they were off and chasing them like a dog on a rabbit.
This drab gray grasshopper that fell prey to the quick WOLF hands is the Carolina grasshopper, Dissosteira carolina. This is one of our largest grasshoppers and is commonly seen on bare ground like the gravel road we were walking. Their slow and lazy flight may be mistaken for a butterfly. They are easy to see in flight but are camouflaged on landing when its outline can disappear.
The brown grasshopper above especially caught my eye. This is the autumn yellow-winged grasshopper, Arphia xanthoptera. It may look drab but wait until it takes off. It produces a crackling-snapping sound in flight called crepitation. The yellow-orange underwings flash brightly until it lands, then the grasshopper disappears in the ground colors. Males may do this to attract females.
The flash of color is a trick similar to the goatweed leafwing butterfly when it lands and suddenly becomes a dead leaf. Strangely enough, this bright color is an effective trick to fool predators. The white tail of a cottontail rabbit or a deer works the same way. Focus on the tail and when it suddenly freezes with its tail down, our eyes are still searching for the white flag. Dirk Seemann's research on this trick is described here.
Pine Tree Spur-throat Grasshopper, considered rare by those hunting grasshopper but occasionally found by us amateurs wandering around with cameras. Good shot, Leslie!
Thanks to Bugguide and Brandon Woo, an undergrad at Cornell and fellow bug nerd, I was able to get a quick identification of these species. Bugguide volunteers monitor the photographs coming in for identification and make life much easier for me.