Use jQuery to remove un-labeled text?

Use jQuery to remove un-labeled text?

Hello! Here is the html example:

<ul>
<li>
<span>June 30, 2009</span> - TitleText <br/>
<a href="http://www.mylink.com">Here is my link text</a>
</li>
</ul>

Without direct access to the html, how can I instead use jQuery to remove the bit after the li span that is "- TitleText"?

I've tried a number of different methods and the closest I have come is removing all the text in the list item rather than just that small portion.

Any help is greatly appreciated!!
+ Dana