Thursday, January 23, 2014

Untold Stories of 2013: When Insects Attack!

While we wait for spring to come, I thought I would share some of my untold gardening stories from 2013. The blog posts I started and never finished.

One of the things I remember most about 2013 was the invasion of insect pests in the garden. Perhaps "plague" would be a more accurate word. Insect pests were everywhere. Some caused quite a bit of damage, while others were more of a nuisance. Some of of these invaders I had never seen before. 

The insect to cause the most widespread damage was probably the colorful Four Lined Plant Bug. I never got a good picture of this critter because they drop from the leaf they are feeding on when you approach. I did happen to get a picture of one having its juices sucked out by an Assassin Bug. Still not a great photo.

Having your juices sucked out by an Assassin Bug is a fitting fate for a Four Lined Plant Bug because that is what they did to the leaves of my Gregg's Mistflower, Gregg Salvia, and Liatris. You can see some of the damage in the upper left of the photo above. Since Gregg's Mistflower and Gregg Salvia grow so fast, they quickly outgrew the damage to their leaves.

The damage to the Liatris, however, was so intense and prolonged that the leaves turned almost white with scabs and I think it cause several of the plants to die when they began blooming. I must say that I am not 100% certain that the damage to the Liatris was caused by the Four Lined Plant Bug, but I am pretty certain.

I tried controlling the Four Lined Garden Bug with a light horticultural oil, but since the insects drop to the ground when they feel threatened, they are hard to hit with a spray of the oil. 

Light horticultural oil is the strongest insecticide I use and I only use it on rare occasions. It is paraffin based must come in contact with the insects to kill them by suffocation. If you can't coat the insect with spray, it will not die. Light horticultural oil also works pretty well on leaf fungus too.

Grasshoppers are always present in Texas. In fact, I disturbed a 3.5 inch long one in the garden this past weekend. The season started out looking like it would be a bad grasshopper year, but I never noticed any more damage than is visible on these rain lily flowers.

The Coreopsis Leaf Beetle is another pest that caused damage last year, specifically to Coreopsis plants. My photos of this insect must have been really bad and I deleted all of them. You can see a great photo and find more information at the link. This beetle pretty much destroyed all of my Correopsis plants last year. I used light horticultural oil a couple of times to control this pest.

I have four varieties of milkweed plants to provide food for monarch caterpillars. I knew when I planted them that I would also have aphids. The two seem to go hand in hand or plant in mouth. 

The aphid infestation on the milkweed was actually pretty light last year. They hit once in the spring and never again. They are fairly easy to keep under control by spraying them off the plants with a strong stream of water from a hose. There are almost always a few lady bug beetles and their larva feeding on the aphids too.

Another pest common to milkweed is the Milkweed Bug. They appeared in the garden about three years ago and feed on the milkweed seedpods. The do not seem to do much damage to the plants otherwise, but they are very prolific. I keep them under control by squishing them between my thumb and forefinger, usually gloved, but not always.

A newcomer to attack the milkweed in my garden is the Swamp Milkweed Beetle. To the uninformed, this pest might look like a large lady bug. Instead of eating aphids, like a lady bug, the Swamp Milkweed Beetle will quickly defoliate milkweed plants. I have only seen the beetle on tropical milkweed in my garden. It does not seem to bother the native varieties of milkweed. This is another pest that is easy to control by the squishing method.

Who knew that an insect attacks the Texas Bluebonnet? I did not, until last year when I found the seedpods covered with Conchuela Bugs. This was another new pest to me. They began appearing after the seedpods began forming. I assume they were feeding on the developing seeds. 

My method of control for the Conchuela Bugs was to move the Bluebonnet plants to the compost pile before all of the seeds were mature. 

Leaf footed Bugs are regular visitors to my Red Yucca plants each year. They hang out and feed on the flower stalks and seedpods. The only thing I do to control these pests is to remove the seedpods. This seems to make them go away for a while until more seed pods form. The plants look better without the seedpods too. Once the flower stalks are about bloomed out, I cut them off and the Leaf footed Bugs will go away, but not far. 

They also like Datura leaves and seedpods. 

Flea Beetles appear during the summer and eat holes in the leaves of some Clammyweed plants. It is interesting that the insects will make some of the plants look like their leaves are made of lace, while a plant inches away will go untouched. The Clammyweed is usually about bloomed out by the time the Flea Beetles hit so it is not much of a loss. Besides that, I am removing the plants by this time of year to keep them from reseeding too freely.
And who could forget the attack of the Big Yellow Caterpillar