'Grasshopper' as a term for a neophyte

What is the origin of using the word "grasshopper" as a term for a neophyte or trainee? The most reliable reference I have is Urban Dictionary, who claims that it is from a 1970's television series called Kung Fu.

I would also be curious to know if this is a term which appears only in American English, or in other countries as well.

Solution 1:

Kung Fu is indeed the source of this expression. Kung Fu made extensive use of flashbacks to the childhood of the protagonist, Caine, as he learned martial arts from his teacher Master Po, who called his young student Grasshopper as a term of affection. It is mostly used humorously, as a lighthearted comparison of the relationship between the speaker and their less experienced listener with that of wise Master Po and his inexperienced student.

The younger generation might be more likely to use the neologism padawan, which was used similarly in the Star Wars prequels as a name used by Jedi masters for their own young students.

Solution 2:

Your Kung Fu reference is spot on.

Here's a quote from Wikipedia concerning the sobriquet Grasshopper.

One of his first instructors was the blind master named Po. Po considered Caine his favorite pupil and behaved more like an elderly grandfather. Caine was given the nickname "Grasshopper" by Master Po. The reference was from an exchange where the still ignorant young Caine asked the old blind master how he could function without seeing. Po asked Caine to close his eyes and describe what he could hear. Caine explained that he could hear the water flowing in a nearby fountain and birds in a nearby cage. Po then asked if Caine could hear his own heartbeat or the grasshopper at his feet (Caine hadn't noticed the insect until that moment). Incredulous, Caine asked Po, "Old man – how is it that you hear these things?" Po's reply was, "Young man, how is it that you do not?" From that point on, Po affectionately called Caine "Grasshopper".

I suppose that calling an apprentice might be found in any country that ran the Kung Fu series.