A skeletonizer infestation is easy to recognize by the work they leave behind. They always come in teams and feast of all the green material in leaves, leaving only a translucent skeleton that looks like parchment.

Recommended treatment by spraying with Bacillus thuringiensis (Bt), which is a microbe naturally found in soil. It works by releasing toxins that target insect larvae when eaten.  The activated toxin breaks down their gut, and the insects die of infection and starvation.

The half-life of Bt toxins  is 1-4 days, and repeated spraying to keep the population down is recommended.

It is available as over the counter product. Please note that there are different strains that target specific insects.

Spraying of effected areas with horticultural oil spraying also proved very effective against skeletonizers.