Pathauto like pattern setting for creating menu link titles
You could use the Automatic Node Titles module to create the titles including the DEV string, which depending on your other settings could appear in the menu: 


  "auto_nodetitle" is a small and efficient module that allows hiding of
  the content title field in the form. To prevent empty content title
  fields one can configure it to generate the title by a given pattern.
  
  When the token module is installed it's possible to use various node
  data for the auto generated title - e.g. use the text of a CCK field
  (since 5.x).


EDIT

You could also create a simple module to change the title of the nodes for the DEV content type:

Custom Node Title


  custom_node_title.info


name = Custom Title (DEV)
core = 7.x
description = Appends appropriate titles with DEV
package = custom



  custom_node_title.module


&lt;?php
/**
*   Custom Node Title Module
**/

function custom_node_title_node_presave($node)
{
    /* only run if node type is correct and '-DEV' is not found in title to prevent duplication */
    if($node-&gt;type == 'article' &amp;&amp; strpos($node-&gt;title, '-DEV') === false)
    {
        $node-&gt;title .= '-DEV'; /* add '-DEV' to title */
        $node-&gt;menu['link_title'] = $node-&gt;title; /* reset menu link to new title */
    }
}


In this example, it changes the title of an Article content type to include -DEV at the end.