Thursday, July 30, 2015

Red Lily Beetle

Lily Beetle
It’s amazing how Mother Nature can contain such beautiful but destructive things. Take the Red Lily Beetle for example. This bright red beetle that some would admire for its beauty but in a matter of a few days it can eat a garden full of lily leaves. It is now on Gardener’s most watched list. The beetle will feed on the leaves of the lily in the larvae stage as well as in the adult stages.
Life Cycle
The adults emerge from the ground in late April or early May and lay their eggs on the underside of the newly emerging leaves of the lily. These eggs will hatch into larva in 7-10 days and will feed for 16-24 days. These larva cover themselves in their own feces to discourage predators. Once the larva’s feeding stage is over they will drop to the soil and encase themselves in a cocoon for 2 to 3 weeks. Then they will emerge in adult form and crawl up the lily and continue feeding. As adults they fly, infecting new stands of lilies with each cycle. In late September or early October they will go into the ground to over winter. The beetle can have two or more cycles per season and can lay up to 450 eggs per season.
The adult beetle is easy to id by it’s bright red body and black legs, head and antenna. The eggs are reddish orange or light brown in color and are laid on the underside of the leaves in irregular rows. The larva are light brown covered with a black goo (their own feces) making them look like black blobs on the leaves.
Biological Control
The best time to start controlling the beetle is first thing in spring when they are mating. Handpick them from the leaves and squish them before they get a chance to lay their eggs. It’s a good idea to place a white cloth around the bottom of the lily to catch any that get away. They tend to drop as a defense mechanism when disturbed.
Because they beetle can have more than one cycle it is important to check the plants throughout the spring, summer and fall months.
Chemical Controls
For an infestation that is out of control a chemical intervention may be necessary. There are a number of products that we carry that will help control the adults and the larva. Using products containing pyrethrum or permethrin will kill the lily beetle. Pyrethrum is a natural chemical that is produced from certain chrysanthemum flowers. It breaks down quite quickly thus it is considered to have a low toxicity. Permethrin is a man made insecticide whose chemistry is based on the natural pyrethrum. The synthetic version is more stable in sunlight thus it will last a little longer in the environment. You will get good control with the Pyrethrum and better control with the permethrin. Both can be harmful to beneficial insects such as lady beetles or bees. Thus they should be applied directly to the insects or infected plants.
What we stock...
Pyrethum Based
Eco Sense Bug –b-Gone
Safer’s End All
Permethrin Based
Dr. Doom
Please see our staff for Application Rates
Susan Jensen Stubbe
Posted by Tammy Jensen at 9:39 PM 0 Comments