To remove the default styles on a select tag apply the rule

select {
  -webkit-appearance: none;

However some browsers can have there own vendor prefixes so for those of you using Sass heres a handy mixin you can include for your convenience

@mixin appearance ($value: none) {
    -webkit-appearance:     $value;
    -moz-appearance:        $value;
    -ms-appearance:         $value;
    -o-appearance:          $value;
    appearance:             $value;

See the Pen Remove Default appearance in select by Brian Best (@brianbest) on CodePen.5308