I've forgotten much about them. If I need to attract several for our quest is it better to plant for each individual butterfly or is it best to use the rainbow? If using the rainbow...which plant do you plant and which wriggly do you hunt for it?
I know I don't need a shroom but will we still possibly get twins if we don't use one? Thanks ..

It's faster to plant for the colours you need but you can do it with rainbow plants if you've got the patience for it.

If you use the rainbow butterpillaflora, you have a 50:50 chance of the butterfly being rainbow, or the colour of the caterpillar you attached to it.  So you'd still need to spot the correct colour of caterpillar, if you wanted to attract a particular colour of butterfly.

You're less likely to get twins without a supershroom, as the mice and dragons can get in, but they're still possible.  If you get twin butterflies they will both be the same colour so if you get the "wrong" colour to the first table, the twin/triplet won't be different.