Dealing with development subdomains

I have a virtualhost that is forwarding to my main domain (e.g. showing the same content that my main domain shows).

Right now my site uses a main domain:www.example.com

And various alias domains:example.comshort.com

I'm creating a new walled garden development site:dev.example.com

But my virtualhost isn't being recognized for that url.

Do I have to create a wildcard record for *.example.com in my DNS host or something?

Here is the pertinent section from my default virtualhost settings (currently in /etc/apache2/sites-enabled/000-default ):

<VirtualHost *:80>   ServerAdmin webadmin@example.com    ServerName www.example.com    ServerAlias example.com    ServerAlias shortUrlEx.com    ServerAlias www.shortUrlEx.com    RewriteEngine On    RewriteCond %{HTTP_HOST} ^example.com [NC]    RewriteRule ^(.*)$ http://www.example.com$1 [L,R=301]    RewriteCond %{HTTP_HOST} ^shortUrlEx.com [NC]    RewriteRule ^(.*)$ http://www.example.com$1 [L,R=301]    RewriteCond %{HTTP_HOST} ^www.shortUrlEx.com [NC]    RewriteRule ^(.*)$ http://www.example.com$1 [L,R=301]    DocumentRoot /var/www/examplepath    php_value date.timezone "America/New_York"    php_value expose_php "Off"    php_value upload_max_filesize 10M    php_value post_max_size 10M... other config options

And dev.example.com is configured as follows (from /etc/apache2/sites-enabled/dev.example.com):

<VirtualHost *><Directory />    AuthType Basic    AuthName "Check Site"    AuthUserFile /srv/dev-example/config/.htpasswd    Require valid-user</Directory>    ServerName dev.example.com    DocumentRoot /srv/dev-example/public_html/    Alias /favicon.ico /srv/dev-example/docs/dev_favicon.ico    php_value date.timezone "America/New_York"    php_value expose_php "Off"    php_value upload_max_filesize 10M    php_value post_max_size 10M<Directory />        Options FollowSymLinks -Indexes        AllowOverride None</Directory><Directory /srv/dev-example>        Options FollowSymLinks MultiViews -Indexes        AllowOverride All        Order allow,deny        allow from all</Directory>    ... further options that shouldn't be applicable...

What am I doing wrong here? How should I configure the default and dev.example.com virtualhosts to allow access to the dev subdomain and use the main domain for everything else?