how to make PNG canvas see-through in pygame when blitting image

I want to blit pawnPic to the screen and leave the background "invisible" or "see-through". right now the white canvas is blocking up the whole chess board block so it looks terrible. Here is the shortened code that im using.

FPS = 30
black = (0,0,0)
white = (255, 255, 255)
brown = (139, 69, 19)
lBrown = (235, 188, 128)
HEIGHT, WIDTH = 960, 960
game_display = pygame.display.set_mode((HEIGHT, WIDTH))
pygame.display.set_caption("Chess")

boxL = int(((HEIGHT-40) / 8))
clock = pygame.time.Clock()
pawnPic = pygame.image.load(r'C:UsersAdjunDropboxMy PC (DESKTOP-BHG02HU)PicturesSaved PicturespawnPic.png')
pawnPic = pygame.transform.scale(pawnPic, (115, 115))
pawn1X = boxL * 3 + 20
pawn1Y = boxL * 5 + 20
Exit_game = True
while Exit_game:
    clock.tick(FPS)
    mouse_x, mouse_y = pygame.mouse.get_pos()
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            Exit_game = False
    game_display.fill(white)
    for i in range(4):
        i += 1
        pygame.draw.rect(game_display, lBrown, (115 * i * 2 - 210, 20, 115, 115), 0)
        pygame.draw.rect(game_display, lBrown, (115 * i * 2 - 95, 135, 115, 115), 0)
        pygame.draw.rect(game_display, lBrown, (115 * i * 2 - 210, 250, 115, 115), 0)
        pygame.draw.rect(game_display, lBrown, (115 * i * 2 - 95, 365, 115, 115), 0)
        pygame.draw.rect(game_display, lBrown, (115 * i * 2 - 210, 480, 115, 115), 0)
        pygame.draw.rect(game_display, lBrown, (115 * i * 2 - 95, 595, 115, 115), 0)
        pygame.draw.rect(game_display, lBrown, (115 * i * 2 - 210, 710, 115, 115), 0)
        pygame.draw.rect(game_display, lBrown, (115 * i * 2 - 95, 825, 115, 115), 0)

        pygame.draw.rect(game_display, brown, (115 * i * 2 - 95, 20, 115, 115), 0)
        pygame.draw.rect(game_display, brown, (115 * i * 2 - 210, 135, 115, 115), 0)
        pygame.draw.rect(game_display, brown, (115 * i * 2 - 95, 250, 115, 115), 0)
        pygame.draw.rect(game_display, brown, (115 * i * 2 - 210, 365, 115, 115), 0)
        pygame.draw.rect(game_display, brown, (115 * i * 2 - 95, 480, 115, 115), 0)
        pygame.draw.rect(game_display, brown, (115 * i * 2 - 210, 595, 115, 115), 0)
        pygame.draw.rect(game_display, brown, (115 * i * 2 - 95, 710, 115, 115), 0)
        pygame.draw.rect(game_display, brown, (115 * i * 2 - 210, 825, 115, 115), 0)
        pygame.draw.rect(game_display, black, (20, 20, 920, 920), 1)
        game_display.blit(pawnPic, (pawn1X, pawn1Y))
    pygame.display.update()

Also if anyone knows, if i have multiple blitted pawns, how do i make pygame know which image the mouse is over without making pygame check individuall each pixel or each board spot