Saturday 17th April
According to my DEFRA handbook on varroa:
"research suggests that colony collapse is very likely before the end of the season if average daily mite drop ... exceeds the following: winter/spring = 0.5 mites, May = 6 mites, June = 10 mites, July = 16 mites, August = 33 mites, September = 20 mites."
Finding 100 mites in seven days means an average of over 14 a day - well beyond 6 mites a day for May, and we're still only in April!
Obviously both colonies are well over the winter/spring level of 0.5 mites per day already so urgent action needs to be taken for both colonies.
