Distinguishing white-tailed bumblebees in the Netherlands: morphology,
ecology and DNA-barcoding
White-tailed bumblebee species, Bombus cryptarum, B.
lucorum, B. magnus and B. terrestris are known to be very
similar in their morphological characters across the majority of their
ranges. This hampers assessment of their status and trends because
reliable identification is difficult. In this study, we use a
combination of characters and methods to assess how ecologists and
citizen scientists can reliably and quickly separate these four species
occurring in the Netherlands. Bumblebees (queens, workers and males)
were sampled from 10 locations across the Netherlands and specimens were
identified based on COI sequence data. Next, the same specimens where
scored for morphological traits. We show that a combination of easy to
recognise characteristics can separate some specimens of the species
depending on caste and sex. Bombus magnus males and queens and
B. lucorum males were most reliably separated from the other
species using morphological characters. Workers of all four species
cannot be separated completely using morphological characters alone.
This is the first time standard morphological characters and ecological
data has been used to study the differences between the white-tailed
bumblebees in the Netherlands. Based on our findings we need to conclude
that the status of these bumblebee species in the Netherlands is
uncertain due to possible misidentifications in the past and present.
People who wish to work with these species should be careful in species
identification based on morphology.