Figure 1. A‒D in Novel splitting/lumping index reflects the history of species concepts applied to bumblebees (Insecta: Apidae)

Figure 1. A‒D: (y axis) species discovery as the cumulative numbers of presently recognized species (SP) described (red squares) and cumulative total numbers of all taxa described (blue diamonds, excluding re-descriptions, replacement names, and infrasubspecific taxa) plotted against (x axis) the dates of the species lists. E‒H: (y axis) the splitting/lumping index SA/SP with red squares for the ratio representing net splitting (SA/SP> 1) or net lumping (SA/SP <1) of presently recognized species calculated as the numbers of species-rank taxa reported by the authors of the species lists (SA), divided by the number of presently recognized species examined by those authors (SP) (the blue line showing the balance point at SA/SP = 1.0), and plotted against the dates of the species lists (x axis). A, E: subgenus Mendacibombus (data from Table 1). B, F: subgenus Alpinobombus (data from Table 2). C, G: subgenus Bombus s.s. (data from Table 3). D, H: subgenus Melanobombus (data from Table 4).