Monday, April 16, 2018

Restoring Bottomland Prairie: Hello, Predators!

In the spring of 2017--Year 5 for our Creek Field restoration--I found bugs I had never seen before.  They turned out to be indicators of maturity in a prairie restoration.

Here is a pair of Jagged Ambush Bugs on the leaf
of a Golden Alexander, in the Creek Field,
April 2017.
  Despite appearances, they
are not mating.   Reproductive coupling is
accomplished by the male approaching the female
from the side.    Yet one bug often carries
another one around, as shown here.  
  
To the naked eye the miniscule insects looked like bits of dead leaf caught on a growing plant.

But a magnifying lens and a post to Bugguide.net helped me identify them as Jagged Ambush Bugs.  The name is apt, as their bodies are strange conglomerations of abrupt, protruding angles.  The genus is Phymata--but the different species of Phymata are hard to identify.

"Phymata" means "swollen" and refers to the bulbous front legs.

 Those bloated femurs
look like crab claws! These bugs are
on Daisy Fleabane in the Creek Field, April 2017.
Phymata engage in double stacking.  It looks like mating but isn't, as actual mating occurs when the male approaches the female from the side.   Some believe double-stacking is a form of mate-guarding; others that the two are hunting together.  


Creek Field, April 2017.

The front legs are so different from the other four! 

Phymata on Golden Alexander in the Creek Field, April 2017.
Note how different the front legs are from the back ones.
The out-sized, muscular front legs help grab a prey.


Though I first saw these bugs in the Creek Field in the early spring, I also found them in the wetlands in the fall:  

Phymata on Hairy Aster, September 2017.


When I noticed a fly caught on Swamp Milkweed in the wetlands, I expected that closer examination would reveal a crab spider as the culprit.   But then I saw the swollen femur....
  
A Jagged Ambush Bug holds a fly with its
swollen front leg.  Swamp Milkweed
in the
Wetlands, September 2017.
Among the ranks of invertebrates at Bird Runner, carnivores are starting to balance the herbivores.     

The restorations are growing up!

No comments:

Post a Comment