Saturday, June 23, 2012

Green Garden Looper

A common pest of the garden is the green garden looper (Chyssodeixis eriosoma). It feeds on a variety of plants including vegetables crops such as basil, cabbage, Chinese pea, corn, eggplant, green beans, lettuce and sweet potato. This pest also infests ornamentals like orchids, ti and other tropical foliage. As the name implies, the looper's movement is distinguished by the typical "looping" fashion. 

The looper’s chewing damage can leave a typical window-like appearance.  This is accomplished by the young caterpillars that consume only one side of the leaf. As the caterpillars mature, they chew holes through the leaves and on the margins.  Some caterpillars will also feed on flowers and fruits.  The larvae are green; the older ones have faint white stripes running the length of their bodies.

The adult moth, with a 1 1/2 inch wingspan, is usually seen flying at dusk. During the day they rest inside flowers, on vegetation, or on walls. The adult feeds on flower nectar and honeydew.

Several parasites are present in Hawaii, as well as other parts of the world and contribute to controlling the populations of the green garden looper. For immediate control, gardeners can spray with Bt (Bacillus thuringiensis). It is a bacterial powder (sold as Dipel, Gnatrol, Thuricide and others) which is an effective organic pesticide specific to caterpillars, fungus gnat and mosquito larvae; it is not harmful to humans.
Bt produces a toxin that causes the affected caterpillar to stop feeding within hours of ingestion. In addition, Bt rapidly degrades in sunlight. For best results, applications should be made in the late afternoon. Most caterpillars feed after dusk anyway. 
Entrust (Spinosad) is another product which can be used against the garden looper and has a low toxicity.