The United States will send eight of its best women's wrestlers in the 17-20 year old age division to Martigny, Switzerland August 17-19 to compete in the 2001 FILA Junior Women's World Championships.      Three wrestlers will be competing on their second straight FILA Junior World Team: Clarrisa Chun (Kapolei, Hawaii/Missouri Valley) at 46 kg, Melina Hutchison (Soldotna, Alaska) at 54 kg and Toccara Montgomery, Cleveland, Ohio (Sunkist Kids) at 68 kg.       Montgomery won the silver medal in 2000, while Hutchison finished in sixth place and Chun finished eighth.     Jenny Wong (Lock Haven, Pa./Sunkist Kids) competed in the FILA World Championships in 1998 and finished eighth.     Montgomery will also represent the United States on the senior level at the World Championships in New York City, Sept. 26-29.     Trials champion Erin Tomeo is unable to attend the championships, and the U.S. is sending the second-place finisher Tori Adams (Amarillo, Texas/Missouri Valley) at 63 kg.     The head coach of the U.S. team for the FILA Junior World Championships will be Tadaaki Hatta of Oberlin, Ohio.     FILA Junior Women's World Championships    Martigny, Switzerland, Aug. 17-19    U.S. Roster    43 kg - Erica Dye, Elizabeth, W.Va.    46 kg - Clarrisa Chun, Kapolsi, Hawaii (Missouri Valley)    50 kg - Jenny Wong, Lock Haven, Pa. (Sunkist Kids)    54 kg - Melina Hutchison, Soldotna, Alaska (Alaska WC)    58 kg - Brandy Rosenbrock, Warren, Mich.(Shamrocks)    63 kg - Tori Adams, Amarillo, Texas (Missouri Valley)    68 kg - Toccara Montgomery, Cleveland, Ohio (Sunkist Kids)    75 kg - Elena Mena, St. Paul, Minn. (Minnesota Storm)