Classification of Honeybee Infestation by Varroa Destructor using Gas Sensor Array

Infestation of bee colony with Varroa destructor proceeds exponentially. It is important to detect the disease at its very early stage. However, the distinction of later infestation stages is also practical. We proposed to apply gas sensor array measurements of beehive air as the source of information which may be useful for this kind of assessment. Honeybee infestation was classified into three categories: ‘low’, ‘medium’ and ‘high’, two categories: ‘low’ and ‘medium to high’, and another two categories: ‘high’ and ‘medium to low’. Responses of gas sensor array to beehive air were used as the input data of the classifier, which was trained to distinguish the categories. The results of the analysis demonstrated that category ‘low’ was determined most effectively, with an error rate of about 10%. Category ‘high’ was most difficult to determine. In this case the lowest error rate was about 20%. Based on our analysis, the approach based on binary classification was favoured and SVM outperformed ensemble of classification trees. It was found, that first several minutes of gas sensors exposure to beehive air were sufficient to attain effective classification. The presented method of varroosis determination, based on beehive air sensing with gas sensors is innovative and has high potential of application in beekeeping.