health white spots on jalapino leafs

[carpy]

quick history on the plant
i gave it to my son last year as a small plnat and also gave him some feed for it he came round the other day and said its taking over his room now do i want to swop it for a smaller 1 so i did but when i got it round and asked him about it he said it hadnt had any feed for about 6-7 months as he ran out (why dont they ask if ye can spare some always got loads lol)
now some of the leafs have white spots on them pic below
is this because they have not have nutrients just water for so long or a disease i dont want to put it in with the rest untill i know as dont want it spreading if it is a disease thanks for you help

 

[laserguy]

Yikes!

If those spots are kinds silvery, could be severe mite infestation?

Would definitely keep that one isolated from your other plants!

 

[gasificada]

Can't say for sure but it looks like burns to me. Strange thing is though, if it hasn't been fed for months, that pretty much rules out fert burn, and if he is growing it in his room, that probably rules out sun burn - unless it sits in a window that cops direct sun.....

Maybe it's something in his water?

Whatever it is though, it sure looks nasty!

 

[carpy]

thank you for your replys

laserguy and gasificada

if he is growing it in his room, that probably rules out sun burn - unless it sits in a window that cops direct sun.....

well saying that he lives on the 9th floor with nothing in front of his flat and the plant was on a window high stand right in middle of his window the sun comes through his window from morning to night.

is there an insecticidal spray anyone would recommend so i can treat it with that as well to cover all angles