# Recognition and identification of species in the Bombus lucorum-complex – A review and outlook

## TL;DR

This paper reviews the challenges in identifying cryptic bumblebee species in the Bombus lucorum-complex and discusses the role of molecular data in resolving taxonomy.

## Contribution

The paper provides a historical overview and evaluates the reliability of morphological versus molecular methods for species identification in the Bombus lucorum-complex.

## Key findings

- Molecular data and pheromone analysis have helped clarify the status of Bombus lucorum, Bombus cryptarum, and Bombus magnus.
- Morphological identification remains unreliable and leads to confusion in the literature.
- The paper outlines current challenges and future directions for resolving species recognition in the complex.

## Abstract

The recognition of cryptic species represents one of the major challenges in current taxonomy and affects our understanding of global diversity. In practice, the process from discovery to acceptance in the scientific community can take an extensive length of time. A prime example is the traditionally difficult taxonomy of the cryptic bumblebee species belonging to the Bombus lucorum-complex. The status of the three European species in the group – Bombus lucorum and the closely related Bombus cryptarum and Bombus magnus – has recently become widely accepted, primarily due to investigations of nucleotide sequences and marking pheromones. In contrast, doubts prevail concerning the validity of species identification based on morphology. As a consequence, our knowledge of the species is muddled in a mire of unreliable and confusing literature data from a large number of authors over the centuries. To clarify this issue, this paper provides a recapitulation of the historical literature and highlights the milestones in the process of species recognition. Further, the possibility of a morphologically based species identification is discussed in the context of new molecular data. Finally, this review outlines the current challenges and provides directions for future issues.