parse question

Hi,
I am a new bie in perl. I have a string as follows

xxxx:yyyy:zzzz:aaaa::bbbb.9.5

I need to discard the 9.5 and my resultant string should be
xxxx:yyyy:zzzz:aaaa::bbbb with .9.5 not be present.

I tried to use split as follows. But its not working as expected. I
will appreciate any help.

use Data::Dumper;
my @str="xxxx:yyyy:zzzz:aaaa::bbbb.9.5";
my @values;
foreach my $val (@str) {
@values = split('.', $val);
}
.