Caterpillars on parsnip foliage. Community › Community › Garden Problems › Pests › Caterpillars on parsnip foliage. This topic has 1 reply, 2 voices, and was last updated 12 years, 1 month ago by Stringfellow. Viewing 2 posts - 1 through 2 (of 2 total) Author Posts 17th July 2014 at 8:14 am #22093 Anne WoodParticipant The caterpillars are back on parsnip foliage. Spray with Bacillius Thuringiensis ( buy on line from Amazon) 18th July 2014 at 7:20 am #25500 StringfellowParticipant Thanks Anne, I’ll keep my eyes open! Author Posts Viewing 2 posts - 1 through 2 (of 2 total) You must be logged in to reply to this topic. Log In Username: Password: Keep me signed in Log In