my dev setup: Mac OSX 10.7.4 / Apache 2.2.21 / PHP 5.3.10

i wish to add conditional logic to my .htaccess files depending on dev vs live environment. for example i want to have authentication on the live server but not on the dev server. i have in my httpd.conf...
SetEnv DEV 1
i have confirmed that this var is set by checking the output from phpinfo(). then in my .htaccess file...
<IfDefine !DEV>
AuthType Basic
AuthName "password protected"
AuthUserFile /path/to/.htpasswd
Require valid-user
but i am still prompted for password on my local dev. it appears that the DEV variable is not available to .htaccess. i do have AllowOverride All set in my httpd.conf for my doc root. any ideas? thanks.