Question
Hi Mike,

I just noticed a crunching sound coming from a line of Japanese Hollies I have (possibly boxwood, but I think it is a Japanese Holly)  Upon inspection, the leaves look like they are yellowing and spotting for good reason. When I open a leaf there are bunches of the tiniest inch worms inside  the leaf I have ever seen. The inch worms are no longer than a 1/16" - 1/8" long> They are very small. The infestation is so bad you can hear it when you walk by. These are  along my front walkway and I have kept them in great shape. I am devastated to think that this will kill my plants. Please let me know if there is a solution to this... oil spray,  deep pruning, is this normal and I just never noticed it before? I am hoping to implement a plan tomorrow if I can get an answer that quickly. Thanks you so much!

Scotch Plains NJ.

Answer
Although oil spray is definitely one option, another is a product called BT. BT is an organic insecticide which is short for Bacillus Thuringiensis, more commonly sold under the brand names Dipel or MVP. It is a dust that is non-toxic to humans and beneficials, but highly effective against caterpillars and worms. As with other organic insecticides like pyrethrum and rotenone, you can purchase this product through on-line catalogs such as Gardens Alive or locally at many garden centers.  

Have a good weekend.  

Mike