Look at the viola part in m.70, the 2nd violin part in m.72, the viola again in ms.74-75, and the 'cello in m.76ff (vastly expanded), and then ms.82-85 falls neatly into place. Also note that the rhythm and conjunct motion show up long before this, but are bent into this particular contour by m.70. The notion of developing variation applies to Bartók quite as much as it does to Schoenberg, even if Bartók didn't use the term. Note also that ms.82-85 are also the simplest and shortest presentations of the motif to this point - in Schoenbergian terms, a liquidation of the motif. In m.177ff, the motif is stated, then further liquidated (rather quickly) and transformed into contrary scale segments.
Now it strikes me on a very cursory read-through of the score that m.44ff, m.103ff and m.132ff are all at least somewhat related to the passages in question; I've probably missed others. Bartók's motivic work tends to be very plastic: extension, gradual change of contour, and expansion/contraction of intervals while maintaining contour are all very much part of his arsenal.