Sunday, October 26, 2014

Rose Weevil

See the holes in the rose petals? That little brown beetle on the bud in the upper right is responsible. It's an adult rose weevil, about 1/4 of an inch long.  Click to enlarge. 
Rose weevils have long beaks with chewing mouthparts at the end. They poke them into rosebuds and munch away, making holes. When the buds unfold, the damaged layers unfurl. Rose weevils lay eggs in some of the holes they drill in buds. The eggs hatch into wormlike larvae that feed inside the bud and can weaken its attachment to the stem, so many infested buds fall to the ground. The larvae come out of the buds, burrow into the ground, and spend the winter there. They eventually pupate and emerge the following year, in time to eat more roses.
A close-up of a rose weevil walking on a rosebud with a big hole in it. Hmm...wonder how that happened?

It reminds me of this poem by William Blake. 

The Sick Rose

O Rose thou art sick. 
The invisible worm, 
That flies in the night
In the howling storms:

Has found out thy bed
Of crimson joy:
And his dark secret love
Does thy life destroy. 

Sunday, October 19, 2014

Busy Milkweed

There is a lot of activity on milkweed plants this time of year. I wrote a blog about some of the members of the milkweed community in October of 2011. You can see that blog by clicking here. 
Today I saw this late instar monarch caterpillar. Its head is on the right. It was eating voraciously, bulking up for its pupal stage, which will come soon. It will pupate for about two weeks and then emerge as a butterfly to begin its long migration south. Click to enlarge.
The plants were covered with oleander aphids like this one. 
A few of the aphids had wings. There is one in the upper right of this photo; winged individuals can disperse to nearby stems and pods to establish new populations. Click to enlarge the photo and you will see that there is a caterpillar-like organism among the aphids. It is the larva of a syrphid fly; it will  grow up to become a hover fly (also called flower fly). In its larval stage it eats aphids. No shortage of those around here. 

A closer look at the fly larva. It is easy to mistake for a caterpillar, or even a plant part. Stealthy! 
As I was clicking pictures of this cluster of milkweed bug nymphs, I got a surprising message from them -- they knew they were being watched and they did not like it. See the picture below. They all ran around to the other side. 
Stop looking at us! 

Sunday, October 12, 2014

The Angel Moth Caterpillar

The angel moth caterpillar. Click to enlarge.
I had uncommonly good luck with caterpillars during my recent trip to Kentucky. This is the angel moth caterpillar, Olceclostera angelica, a  member of the Bombycidae family of silkworm moths. Angel moth caterpillars usually feed on lilac or ash. This one was on a wooden fence post, probably after falling from a host plant. I saw it near the historic entrance to Mammoth Cave in Mammoth Cave National Park. It is an uncommon caterpillar, not often seen, and, like the spun glass caterpillar I saw nearby and wrote about recently (click here to see the story) -- I had never seen one before.

The longhaired angel moth caterpillar grows up to be a handsome furry-legged moth with a glittery abdomen and silver-grey scallop-edged wings that made the scientist who named it think of angels. Click here to see a photo of the moth.

Sunday, October 5, 2014

It's Locust Borer Beetle Time!

The locust borer beetle, Megacyllene robiniae. Click to enlarge.
Goldenrod is one of my favorite things about autumn. I can spend hours inspecting the bright yellow flowers, finding and photographing the insects it attracts -- like this locust borer beetle. It is a "long-horned" beetle in the family cerambycidae. Check out its long antennae.

You may be wondering why it is not called the goldenrod beetle...

Although we usually notice them on goldenrod in autumn, they spend most of their life cycle on locust trees. Adults lay eggs on locusts. The eggs hatch into larvae that spend winter under the tree's bark. When the weather warms, the larvae burrow deeper into the tree and pupate there. They emerge as adults in late summer and early autumn. Egg, larva, and pupa live on locusts; adults are found eating goldenrod pollen, but they hang out on locust trees, too, and eventually lay their eggs there. Calling them locusts borers makes sense after all.

There are more pictures in my previous blog about locust borer beetles. Click on this sentence to go there. I get excited about seeing them every year, so the chances are good I will be writing about them next October, too. :-)