MILWAUKEE, Wis. Thursday, March 28--Despite serious shortages of volunteer canvassers, Senator Eugene J. McCarthy's Wisconsin headquarters continues to turn away student workers from Eastern colleges.

Marge Sklencar, national volunteer coordinator, said last night that Eastern students are needed in forthcoming eastern primaries--particularly in Connecticut and Pennsylvania. "Sure we need more people here," Miss Sklencar said, "but we also need people in the East--and we can't draw from the same sources."

McCarthy's Wisconsin organization Tuesday night cancelled a scheduled flight of student volunteers from Harvard. Benedict Stavis, Wisconsin canvas coordinator, said "time and geography" influenced his decision to tell Harvard students to stay in the East. "We told them to work in Connecticut and send us the money," Stavis said.

McCarthy for President headquarters in Milwaukee is almost a week behind schedule in its canvas of voters. Stavis gave three reasons for the delay:

* The blizzard that swept the Ohio valley and Mid-Atlantic states last weekend which forced the cancellation of many bus trips;

* The reluctance of McCarthy's Madison headquarters to send University of Wisconsin students to the Milwaukee area;

* The overly-optimistic estimates by mid-western colleges of the number of volunteers they could deliver to the McCarthy campaign.