Insects at the Wetlands, 09-09-18

I headed out to the Cosumnes River Preserve to see how things looked there.

On the way to the preserve, I counted 15 hawks along the highway (not including two that had been hit by cars), and that seemed to bode well, but at the preserve itself it’s still pretty bleak. They’re just now starting to pump water into the wetland areas, but today there was only a puddle at the far end of the boardwalk. Not enough to support many birds; and what birds were there flew off as soon as they saw me.

There is also no water along Desmond Road, so nothing to see there either. I DID get to see a handsome juvenile Red-Tailed Hawk along the also-empty slew. It had landed on the cracked and dried bed of the slough… but was then chased off by a very brave ground squirrel. The hawk flew up into the naked branches of a nearby tree, and I was able to get quite a few photos of it before it took off again.

CLICK HERE for the full album of photos.

Since there wasn’t much else to see, I pulled by focus in tighter and started combing the few surrounding trees and shrubs with my eyes for any sight of galls, insects and other stuff like that. It took a little time, but I was rewarded for my patience.

I found single specimens of three different species of dragonfly: Easter Forktail, Green Darner and Blue Dasher. All of them were in the trees, not moving, trying to warm themselves up in the morning sun. I also found several Praying Mantises (mostly boys and one girl), and a fat adult Katydid. I got some of them, including the Katydid, to walk on my hands. I also spotted some Trashline Spider webs but couldn’t see the spiders themselves.

Along the road I found a large bird’s nest that had fallen out of a tree, and, sadly, some road kill including an opossum and *waah! a Black-Tailed deer fawn. The fawn was smashed flat, so it must’ve been hit by a semi or something. I can’t imagine how traumatic that must have been to its mother. The fawn was a newborn, still in its spots…

As for the galls, I also found several different kinds: Spiny Turbans, Club Galls, Round Galls, Oak Apple galls, and every some “Woolybear” galls (Sphaeroteras trimaculosum). There were also the galls of the Ash Flower mite on an ash tree.

My sister Monica had asked what “galls” were specifically… Galls are malformations caused by the interaction between a plant and an insect (like a wasp or midge or mite), a plant and a fungus (like rust fungus), or a plant and another plant (like mistletoe). To protect itself from the insect, fungus or other plant, the host plant (or tree) forms a protective layer of material over the intruder, and that protective layer is the gall. Galls can be in the leaves, in the bark, on the branches, or on the flowers, seeds, catkins or acorns.

The Woolybear galls I saw today, for example, are formed on the backside of oak leaves when a cynipid wasp lays its egg on the leaf. A chemical in the egg tells the tree “grow something here”, and also gives it a blueprint of what to grow. So, what you’re seeing in the photos is actually fuzzy plant material that the oak tree grew to protect itself from the developing critter inside the egg. The wasp larva grows inside the gall and then exits when its mature. Each wasp species has its own unique gall (and some have two different ones in the same year).

Anyway… I walked for about 2 hours and then headed back home.