Welsh international Robinson has been a key figure in the Premiership this season for Gloucester and has been in excellent form lately as his team make a charge for the play-offs. He brings with him top-level experience to Wasps, with 13 international caps.
Ryan Davis' form has also been very impressive this year with Exeter, the Premiership's newcomers. He too brings international experience with him as the 25-year old is a former England U16s and U18s international who captained his country at U21s level in the 2005 Six Nations. He spent six seasons at Bath before moving to Exeter.
"We are really pleased to be able to bring in two experienced Premiership players in such a key position. With Dave Walder leaving, it was vital that we brought in talented replacements and we think these two players will fit in very well at Wasps as we look to strengthen our squad for next season," said Wasps chief executive Chris Thomas.
On Walder's departure Thomas said: "Having been with us since 2006, I know I speak for everyone when I say that Dave has left a real mark on the club. He has decided to prolong his career by playing abroad, something he has always wanted to do, and we fully support that decision. Everyone at the club appreciates what a key role Dave has played for us in recent years, on and off the field, and while we are sorry to see him go, we wish him the very best overseas. The important issue for us is that we are all completely focused on the remainder of this season and send Dave off on a positive note."