what is this pest? i have pics

there is a pest attacking my lychee tree and i do not know what it is. this pest is very small and is very white and cottony, i try to scrape all of it off my tree's leaves and branches every day but the cotton balls always come back. also when i scrape them off, they seem to mash together like mold does. there are also little webs on my tree that i can barely see. the tree's leaves are also sticky. this pest seems to be damaging the new growth on my tree. i tried using a pesticide to get rid of it but it did not work. my tree is dying slowly too because its leaves have burnt tips even though i water it enough, the burnt tips keep climbing up the leaves. can you help me try to identify this pest so i can kill it? pictures below, click to enlarge.

 

HI Malsprower,
It small so i can't see clearly but i think it is mealy bug.

 

The webbing is produced by spider mites.

 

the fluffy white things are mealy bugs. dip a q-tip (cotton swab) in rubbing alcohol and then touch the bugs - the alcohol will kill them. make sure to rub the qtip along the stem in the general area where the bug is to get any eggs that may be laying around.

repeat as needed - usually it's a couple of treatments within a few weeks time to get all of them.

don't know if the rubbing alcohol will work for the spider mites - probably.

 

Malsprower, I'd go with scale. Look up 'scale insects' and 'cottony cushion scale'. There are LOTS of different kinds of scale; I've seen them in white, red, and brown so far. Some look like tiny helmets, others look like walking cotton balls.

When I have a lot of them on a plant, I prune the worst spots into a garbage bag, add some bug spray, and tie wrap it shut for disposal. Then, I start working on the remaining scale on the plant by either squishing it, prying it off into a zip-lock baggie, and sometimes carefully torching it with a lighter (it's a finger burner if you try too many that way, but when there's one hiding out where the branch splits and you can't get it any other way it sure does work.)

I've never had much success in total scale removal, but I've gotten some populations down enough that my plant resembles a plant again. I had a small Cassia plant that kept getting scale so bad that it finally died, so I planted a different kind of Cassia for my butterflies, and it's done much better.