Archive for September, 2012

The Accused and the Culprit

Hayfever season affects so many people. The sneezing, watery eyes begin, and all the sufferers see is the profilic bloomer goldenrod. It gets accused for all their suffering. They never notice the actual culprit, the ragweed (Ambrosia sp).

Do you see the ragweed in this picture taken in my backyard?

I rest my case.

Average height of most ragweeds is 6 feet or so. Giant ragweed can reach 17 feet tall! Peterson’s Field Guide to Wildflower shows 31 species. Illinois has 5 species.

Goldenrods (Solidago sp.) grow to 5 feet tall, with Illinois having 25 species.

This picture shows the male ragweed flowers beginning to bloom,

and this one shows them from the underneath side. Ragweed is pollinated by the wind. Insects pollinate the goldenrods.  (The flowers in this picture haven’t started blooming like in the picture above.)

Female flowers are practically hidden in the leaf axils. If you look closely, you can see yellow stamens.

These flowers were pollinated, and the seeds are developing.

Wonder if this holds one or more seeds?

Obviously, goldenrod is attractive to insects and not the cause of hayfever.

Assassin Bug

This assassin bug’s dark color made it easy to spot among the goldenrod flowers.

  I took picture after picture because of the low evening light and a breeze. The assassin bug didn’t much like that and kept moving around. Then I noticed it was feeding on prey. Assassin bugs wait patiently and ambush their prey. Its long beak then injects the victim with a lethal toxin that dissolves its insides. The assassin bug then sucks out the “juices.”

The assassin bug was feeding on a moth caterpillar, called a camouflaged looper (Snychlora aerata). These caterpillars attach small plant pieces to their body, so they blend in with their surroundings.

Since I wasn’t able to get a good picture of the caterpillar, I’m including one taken during a previous summer.

Isn’t it impressive … and convincing in its floral attire?  The caterpillars like open habitats and mostly composite flowers. Black-eyed susans and salvias are a favorite of theirs in my gardens.

Thistles … Have Visitors?

What was this crab spider thinking? How did it even get on the tip of this thistle bud?

How can prey get to it?

Thistles have bloomed for a while out in the middle of my weed patch because there’s more sun light there. I’ve been watching the shorter ones growing on the south side of the weed patch. They are getting more sunlight now that the sun’s moving farther south.

The pattern on the buds looks like it’s been stitched, and I’ve photographed it often.

Only tiny insects could crawl around on these plants.

The words hostile environment come to mind.

I checked the spider in the evening, and it was gone. I assumed it lowered itself on a strand of silk … wonder if it lowered itself onto the bud in the first place?

These pictures are from the next evening.

This one was on a different bud. It didn’t like the attention, and

it did a quick side-step, angling downward. It also angled its body outward.  I assumed this posture was meant to threaten me by making itself look bigger.

Then it resumed its patient-waiting position.

I didn’t see the tiny jumping spider at the base of this bud until I saw the picture on the computer. Obviously, thistles have more activity around buds than I expected, and will have even more when they bloom.

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Then I found more interesting things around the thistles this evening. (the next night).

This spider’s pale coloring and faint markings makes me think it recently molted.

Three of the thistles changed dramatically in the last 24 hours. If you look close, about a third of the way up, you’ll see a tiny darkish winged insect.

The prey here looked like maybe a beetle. It was a 16th of an inch at the very most.

What Long Legs You Have!

Buffy and I walked along a food plot where a lot of milkweeds bloomed earlier this summer. A few seedpods were opening, and the seeds waiting for the wind to carry them away.

The seedpod had long legs that could only belong a daddy longlegs. Its body sure resembled the seeds. What would one be doing under a “pile of fluff?”

I didn’t see the 2 tiny red bugs until I put the picture in the computer. So, obviously, it knew what is was doing.

An Odd Behavior

They don’t call skippers “skippers” for nothing; they can “skip” away so fast I don’t see them go.

So, when I went in close to take a picture and the skipper stayed there, I knew something was going on.

My suspicions were correct; it was prey to a crab spider. Crab spiders can change color to match the color of the flower they’re on. They ambush their prey, inject it with venom to immobilize it. They then feed until the victim is sucked dry.

The victim was a male fiery skipper (Hylephila phyleus). Their wingspan measures 1 1/4 to 1 1/2 inches.

 When I went out after supper, the skipper lay on the ground. I twisted the stem of the salvia to see the spider. Females are much bigger than the males.

Goldenrod Bunch Gall

Goldenrods make up a good percentage of plants in my weed patch in our backyard. This summer many of them have this abnormal growth caused by a gall midge.

This growth is called a bunch gall, rosette gall or flower gall. It’s caused when a gall fly lays an egg in a leaf bud. After the egg hatches, the grub somehow keeps the stem from growing.

Obviously, the grub/gall doesn’t seem to affect the plant’s overall health.

A Carnivorous What?

If I didn’t know a relatively unknown fact, I wouldn’t get too excited over finding 2 woolly aphids.

The reason for my excitement, you ask? North America has one carnivorous caterpillar, and it feeds on woolly aphids. I’ve only seen a handful of the harvester butterflies over many years, and only seen their caterpillars once 5 years ago.

My grandkids were in town, and I took my oldest grandson hiking at one of my favorite spots. These caterpillars were considerate enough to be right beside the trail.

Obviously, they blend in well with the aphids. Host plants for these aphids include alder, ash, beech, greenbrier, hawthorn, maple and witch hazel. I was so excited, I didn’t even think to check what plant they were one.

I assume these aphids are on what’s left of leaves.

The aphids and caterpillars covered a relatively good-sized area of the shrubby tree.

It looks like one of the young caterpillars just molted by the “ball” of white fluff.

 The harvester butterflies (Feniseca tarquinius) stay near the aphids too and feed on the honey dew they excrete.

The caterpillars grow to 3/4 inch long. I don’t have any pictures of the butterfly. They have a wingspan to 1 1/3 inch wide and are a pale brown butterfly underneath with small white-edged circularish patterns.