The U.S. Geological Survey reports that a 4.4 magnitude earthquake struck south Reno at 10:46 p.m. Tuesday night; the strongest of a cluster of at least ten quakes centering in the area of the Arrowcreek Country Club.  The swarm of temblors began a half hour earlier with the first shaker registering 1.9. At least four other quakes in the swarm registered over 3 on the Richter Scale.  One temblor within the timeframe took place out of the main epicenter, near Vista Terrace in Sparks, about 20 minutes before the largest upheaval in the swarm.  One aftershock registering 1.7 occurred just east of the Reno Tahoe Airport shortly after 11.