I usually switch BSTs from what I find them on and I've never had a BST cat refuse to switch from one BST hostplant to another species of BST hostplant. But I've never done fennel to parsley.

KC

I have switched them. I often will put parsley, fennel and dill in the cage with them as I'm rearing them and they will select themselves. I've never had a problem but I'm curious to see how the other more experienced posters respond.

~Laura

Thanks. I will put them on parsley and see how they do.

With the BST, when I've had to switch mine from one type of host plant to another, I usually just offer them the new host plant while they're eating some of the original host plant. They've always moved over to the new plant material.

Right now I have Fennel, Parsley and Rue and no matter which host plant they started with, they're eating whatever is offered. They are quite the little pigglets ... :-)

Mary

I moved them and right away they crawled onto the parsley.
Can't be sure they are eating it, but it all seems like they are ok with it.

The baby cats seem to have a preference for the host plant that they were born on, but will readily adjust to others. I usually do what Mary does, and offer several different host plants inserted into the same floral foam cube. I actually enjoy making little herbal bouquets for them and they look kinda pretty. BSTs have accepted all the host plants, including large leaves of Zizia aptera, which mostly the large caterpillars eat.

Wow, I wish the BST's around here weren't so finicky! All mine want is fennel, fennel, fennel! I had a huge parsley plant and none of them would go near it. I try sneaking some into their "condo" and they just ignore it. I'm running very low on fennel, so wish they would eat something else. I think it was the year before last I did buy some dill and get them to eat that, but dill smells so strong it really overtakes the room! LOL.

I always switch mine from fennel to dill and they love it.

Betty