will this spread???

i am growing some mj and tomoatoes and cucumbers....the cucumber started to wilt its been a week so ive given up on it.but when i got a closer look i saw some lil fly thing and some other little white fly things in the soil..
my question is will it spread to my mj and tomatoes?? and how to prevent

I would think so. If I were a bug and ate a cucumber I would have no problem eating a tomato or cannabis plant. Sounds like you need to figure out what it is.