3. Available methods and markers
There is no morphological "key" to honey bee subspecies, no simple logical tree based on a sequence of single discriminating characters. Instead, measurable morphometric characters show gradual changes and their ranges mostly overlap between subspecies. Thus, subspecies often differ only slightly in the mean values of several body characters, and therefore advanced statistical methods are required for discrimination of groups. The concept of numerical taxonomy was introduced into honey bee taxonomy by DuPraw (1964, 1965) and further elaborated by Ruttner et al. (1978).
The table on page 7 shows 31 different markers, and with those "advanced statistical methods are required for discrimination of groups"
I would imagine that the more markers you have, the less challenging is the math required to reach a (more probable) result. Given, however, that beekeepers have been selecting for particular wing pattrerns for some time, I would guess that one is close to useless!
From the same report, the bit we should really take notice of:
"Honey bees show considerable geographical variation, resulting in adaptation to regionally varying factors of climate and vegetation, but also to prevailing pests and pathogens. However, this natural heritage is increasingly subject to diffusion by human beekeeping efforts at a worrisome speed. The demand for high economic performance of bee colonies, combined with desirable behavioural characteristics, has led to considerable changes caused by systematic bee breeding. Thus, the original geographic distribution pattern is being dissolved EU-wide by mass importations and an increasing practice of queen trade and colony movements. These activities endanger regional races and ecotypes by promoting hybridisation (De la Rúa et al., 2009; Meixner et al., 2010), and by adding various breeder lines with distinct properties to the picture. Yet another dimension is added by the deliberate replacement of native subspecies in some regions by non-native bees with more desirable characters and greater commercial interest (for instance, the replacement of A. m. mellifera in northern and central Europe by A. m. carnica or A. m. ligustica) (Bouga et al., 2011).
The downside of these economically driven processes is an increasing trend towards uniformity of honey bee populations across Europe, leading to a loss of both genetic diversity and specific adaptations to local conditions (reviewed in De la Rua et al., 2009; Meixner et al., 2010).
Honey bees are particularly sensitive to inbreeding (Seeley and Tarpy, 2007 and references therein). Therefore, the loss of genetic diversity is of grave concern. It has been shown that colonies with reduced genetic diversity are less capable of controlling hive temperature (Jones et al., 2004) and more prone to develop diseases when challenged by parasites (e.g. Tarpy, 2003). This reduction in genetic diversity may also affect the capacity of honey bee populations to adapt to new threats, such as newly introduced parasites like varroa.
Thus, there is a widely recognised need to encourage regional breeding efforts to preserve local adaptation, and to maintain local strains in isolated conservation apiaries."
Back to where we started: what matters is that we help the local variants - of whatever ancestry - to adapt to varroa, and thus thrive and preserve their diversity. To say that another way, we stop treating and/or manipulating against varroa.
Standard methods for characterising subspecies and ecotypes of Apis mellifera
Marina D Meixner1*, Maria Alice Pinto2, Maria Bouga3, Per Kryger4, Evgeniya Ivanova5 and Stefan Fuchs6