This is an important industry update. Google has decided to drop the crawl rate for news sites. You can see your Google crawl rate in the Webmaster Tools crawl rate report.
Apparently, they have figured out a way that they do not need to crawl news websites as often. See tweets from Matt Cutts below.
If you have a news site and it looks like Google is crawling less since ~3/7, don't worry. Google News added if-modified-since support then.
— Matt Cutts (@mattcutts) April 8, 2014
So it's just Google News doing smarter crawling now. More info about if-modified-since: https://t.co/1TrtFVnypD
— Matt Cutts (@mattcutts) April 8, 2014
This was reported on by Search Engine Land. So if you are seeing a large drop in crawl rate and you are news site, you know why.