Caterpillar Control

 Bacillus thuringiensis, or Bt, it a bacterium found naturally in soils across the world that infects and kills Lepidoptera larvae, but causes no harm to humans or animals. This is because the bacterium is activated in high pH conditions which occur in a caterpillar gut. This is different from the human gut which has a lower pH and is more acidic. Bt breaks down the insects gut lining and the insect dies of infection and starvation. 

Bacillus thuringiensis strains 

Watch this short informational video about Bt from the National Pesticide Information Center (NPIC). 

 Sound Horticulture carries several products with Bt. 

Javelin contains the active ingredient Bacillus thuringiensis kurstaki 85% that offers broad spectrum control of mixed caterpillar populations in tree and vegetable crops. NOP approved as well as OMRI and WSDA listed.

DiPel also contains Bacillus thuringiensis subspecies kurstaki (Btk) 54%.  Globally, DiPel has become a cornerstone insecticide in many IPM programs as it offers high quality, cost-effective, broad-spectrum caterpillar control on more than 200 crops. OMRI listed.

Insecticidal soaps, horticulural oils and azadirachtan (neem) products can also help with caterpillar control. 

Know the difference between caterpillars and sawfly larvae. These two insects closely resemble each other, yet Bt is not effective for sawfly larvae. 

Besides these highly effective pesticides, there are several beneficial insects that are great for caterpillar control. 

Trichogramma is a tiny parasitoid wasp that attacks the eggs of many species of moths, including cabbage looper, codling moth, twig borer and fruit worms. There are several species of Trichogramma that are available. Use platneri for general use, minutum on the east coast, and brassicae for cabbage/row crops. 

Orius insidiosus, the minute pirate bug, will feed on many types of soft bodied pests, including small caterpillars and pest eggs. 

The green lacewing, Chrysoperla rufilabris, larvae is another generalist predator that can be used for caterpillar control. 

Invite wild birds into your garden as natures best pest control. Birds consume millions of pounds of insects worldwide each year. 

Visit this pictorial guide to caterpillars from the University of Missouri Extension to help identify the caterpillars on your crops. Enjoy the butterflies and prepare for the pests this year, Sound Horticulture is always there to help!