Entomopathogenic fungi are notoriously difficult to work with.

Somewhere in the 19teens an entomopathogenic fungus was introduced in  
Mass. to help control Gypsy Moth.  It apparently disappeared.   
However, in 1989 an unusually cool damp summer in the NE it was found  
to be causing mortality across NY.  The fungus was possibly  
misidentified for  years, but was spreading with the Gypsy Moth  
populations.  In 1990 a Grasshopper fungus was introduced into Alaska  
in attempt to control a grasshopper population that had exploded near  
Delta Junction--again--the introduction was thought to be a failure  
until in 2000(ish) calls came back to our lab of huge epizootic in the  
area of release.

In a hive there are huge barriers to overcome.  Temperature, matching  
fungus to host, humidity concerns and activity of the bees all need to  
be factored.  One might find a hot isolate that works well in lab &  
field tests but slow growth in commercial culturing may make it  
infeasible for production.

A common practice in our lab is to pass the fungus through the host  
several times--this increases virulence sometimes several fold.

Because the host organism is biological in nature and the control  
organism is also there are very specific timing, environmental and  
host activity (hygienic) that can reduce the effect.  Looking at the  
history of using insect pathogenic fungi for control of insects -- 
progress is slow but progress is being made.  After 20 years of work  
with these fungi I have seen many failures but am optimistic that  
progress is being made such that products are making it to market.

Example--I was talking to a neighbor that produces thousands of bales  
of hay for the equestrian markets in the area.  He is using a hay  
amendment (fungal antagonists) to reduce the build up of mold in bales  
of too much moisture.  This research was started more than 15 years ago.

Note:  isolate selection (or species) will be the biggest first step.   
unfortunately, we have very little information on the genetics of  
pathogenic fungi to really understand the processes to select  
candidates for best control.  Currently, labs use isolates that are  
"hot" work in the lab and are easy to grow. This may not be the best  
criteria for selecting something that works in the field under  
commercial beekeeping conditions.

Mike Griggs
Entomologist/ Support Scientist
Biological Integrated Pest Management Unit
President Finger Lakes Beekeepers

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