What is the origin of the term blighter as in "you little blighter"? Was it originally more or less "rude/abusive" than now when it is a fairly mild term?

The term started in the 1930s.
http://wiki.answers.com/Q/What_does_cheeky_little_blighter_.

The term 'Blighter', was first used in English Literature, sometime before 1913...

https://www.merriam-webster.com/dictionary/blighter says 1822 (satguru)

It was said by a Junior Officer on the Titanic, Hsrold Godfery Lowe.."One of the sailors near to him was so tired that he could hardly pull his oar. The Japanese bustled over, pushed him from his seat, took the oar and worked like a hero until we were finally picked up. I saw Mr Lowe watching him in open-mouthed surprise.
"By Jove!" muttered the officer. "I'm ashamed of what I said about the little blighter. I'd save the likes o' him six times over, if I got the chance."
http://www.encyclopedia-titanica.org/titanic-biography/harold-godfrey-lowe.html

The origin according to dictionary.com was in 1815- 25, from the word 'blight'

http://dictionary.reference.com/browse/Blighter

CHEEKY: adj risqué; just short of rude. You’re being cheeky if you make a joke that you can only just barely get away with without getting into trouble.

BLIGHTER: adj guy (or, rather, a more refined, more upper-class version thereof). Usually used in a slightly critical tone: Just wait until I get my hands on the blighter who steals my newspaper every morning.

http://septicscompanion.com/dictionary/cat_insults.html

This states, that the origin of blighter, lies in the late 19th century.

http://books.google.com/books?id=5QIv39cbUMYC&pg=RA1-PA53&lpg=RA1-PA53&dq=cheeky+little+blighter+origin+meaning&source=bl&ots=l2NKwts-ZL&sig=NI4XvsvYzx9lxmoy4KTBnfPsqFs&hl=en&ei=zloNStjVA5C6tgPj8sDpAg&sa=X&oi=book_result&ct=result&resnum=5

'The Spaniard that blighted my life' was recorded in 1911 by Billy Merson -
"If I catch Alphonso Spagoni, the Toreador
With a mighty swipe I will dislocate his bally jaw!
I'll find this bullfighter, I will
And when I catch the bounder
The blighter I'll kill
He shall die! He shall die!
He shall die tiddly-i-ti-ti-ti-ti-ti-ti!
He shall die! He shall die!
For I'll raise a bunion on his Spanish onion
If I catch him bending tonight!"
http://lyricsplayground.com/alpha/songs/t/thespaniardthatblightedmylife.shtml