There are quite a few swallowtails that use citrus as a host plant - I feel sure these are some type of citrus eating swallowtails. The ruby-spotted swallowtail/Papilio anchisiades is a beautiful butterfly of Central and South America, whose caterpillars congregate in groups - that's probably what these are, but, there could be others that I'm not familiar with.
Sherry

Thanks so much Sherry.

So did you buy the plant or ask for the caterpillars?

I didnt buy the plant or ask for those caterpillars because i wasnt sure what they were.
however there was another citrus with giant swallowtail cats on them, i bough one of those plants and asked to collect the giant swallowtail cats. I brought them home and they are eating away!

When i visit the nursery again i will purchase a plant if i find these ruby spotted swallowtail cats on it!
i think im going back there on sunday :)cant wait

Siam

Siam, I'm not positive they're ruby-spotted swallowtail caterpillars, but given their similarity in shape and overall look to giant swallowtails, I'm sure they're some type of citrus swallowtail. The only type citrus swallowtail that I know of whose caterpillars congregate is the ruby-spotted swallowtail. Even if they're another type swallowtail, they'll be big beauties!
Please post a picture of one of the chrysalides - I bet it'll look a lot like a giant swallowtail chrysalis.
Sherry

Sherry, i will. Im keeping my fingers crossed that when i go back to the nursery, i find them! gonna buy the plant and the cats, and then i'll know exactly what they are when the eclose!!
Siam.

OK so i did go back to the garden centre and bouth the citrus plant that those caterpillars were on. I got the caterpillars stil there on it also. Turns out it is a calamondin citrus plant.
Im going to try raising the cats indoors , so hopefully we can see what they turn into :D
Siam.