I think I may have blogged before about the ProMED-mail “global electronic reporting system for outbreaks of emerging infectious diseases & toxins.” You can get email alerts and also produce maps for plant diseases, such as this one:
Unfortunately, the system only covers infectious diseases. It is a programme of the International Society for Infectious Diseases, after all. Otherwise, it would have picked up the plague of armyworms currently affecting Liberia. A quick search of my feed reader revealed outbreaks in Namibia and Zimbabwe within the past two years. And Google Trends shows some interesting, ahem, trends in searching News archives show this timeline for news of this pest ((The search expression was: (armyworm OR “army worm”) AND outbreak.)) over the past few years:
There’s research on natural enemies going on, but that’s not going to help Liberia right now.