Acaroid, a grass star in the early 1980s for James and Virginia Binger's Tartan Farms, died April 12 of an apparent heart attack in his paddock at Gilda Clark's Timber Creek Farms near Mitchellville, Iowa. The 28-year-old son of Big Spruce out of the Intentionally mare Arachne was buried at the farm.Beginning his career on dirt, Acaroid went winless in his first three starts, then won four consecutive races after being switched to grass, including the 1981 Lexington Handicap (gr. IIT) at Belmont Park.Trained by Jan Nerud, the Tartan homebred was at his best two years later. He won the United Nations Handicap (gr. IT) at Atlantic City at the time the race was one of the nation's premier grass events and the Manhattan Handicap (gr. IIT) at Belmont. He placed in two graded turf stakes that year.Acaroid was retired after the 1983 season with 10 wins from 27 starts and earnings of $452,907. He first stood at Tartan near Ocala, Fla., then later at Harry Mangurian Jr.'s Mockingbird Farm near Ocala before ending up at Timber Creek in the mid-1990s.Acaroid sired important grass stakes winners Captive Miss and Klassy Individual. The former scored her big win in the 1992 Queen Elizabeth II Challenge Cup Stakes (gr. IT) at Keeneland, and Klassy Individual captured the Black Helen and Columbiana Handicaps at Hialeah. Overall, Acaroid sired six stakes winners and the earners of $6.7 million.