For spider mites I use Spinosad, which is a new and relatively safe product. It is not systemic, but it works by either contact or ingestion. It does not harm most beneficial insects, but it is toxic to bees for a short time while it is wet. It is also toxic to caterpillars, but you could use it at times of the year when caterpilars aren't present. See the link below. You can also discourage spider mites by frequent spraying with water and high humidity.

Most passionflowers are happy with soil that is slightly acid to neutral, about 6.0-7.0. You can read more at: http://www.passionflow.co.uk/mineral1.htm

Here is a link that might be useful: Spinosad info

Are you growing them in greenhouse or outside? I expect it is pretty dry at the moment either way because that's what they love. A totally safe method as suggested on the link below try hosing the plant foliage down twice daily particularly from underneath on high power. Mixing a little soap solution will help but just the power of the jet should do it. I have lots of Passiflora growing into each other outside and rarely bother treating any spider mite problems. Some species and hybrids are just very prone to it. If you are growing in a greenhouse the problems are always worse but it is easier to bump the humidity up.
Myles

Here is a link that might be useful: Spider mites.

thank you both for your advice greatly appreciated.i am going to try jet spraying with water.rite now in south florida it is dry and we are about to get a cold snap here on wed so im a bit nervous of some of my babies.so it is not very humid rite now.i used to spray systemic for scales but thee product i used was recalled and i havent sprayed in like 5 months now i have spider mites.i spray most of the vines i have growing on my fence but leave some for the caterpillars.i have 14 or so growing in pots next to each other which i havent sprayed since ive had them but found spider mites on them so gotta take care of it...another question...i have passiflora nelsonii about to bloom i suspect 2morow seeing though the cover over it, like triloba, has finally stared to split open and i can see the bud...now weather predicts it is supposed to be like 37 on tues nite is the cold going to effect the bloom...it should get about 39 if they say 37 we are closer to the ocean...hopefully it opens and ill post a picture ...well thank u for the advice once again...have many more questions and pictures to post....

I had them on my jasmin and spayed a lot with soap and alcohol and water ..used a cotton swab on infestations..Now I'm scared my new Passiflora caerulea will get something all on a porch scared to loose any buds and we are in a real cold snap to boot ...It looks like I took care of it as all the leaves fell off the jasmen after alot of treat ment ..It does this once a year and then comes back especially after blooming so much ...
Do u guys think it will be over or keep going the safe soap and water sprays seem to irritate plants if sprayed weekly any sugestions? Thanx