Neighbor-joining phylogenetic tree of 180 envelope sequences. Taxon names preceded by a "D." (obscura species group) or "S." (Scaptomyza elmoi) are from this study. All other sequences are from GenBank,  and . Bootstrap values are shown for distance (before slash) and parsimony (after slash) analyses. Values are shown for major clades only. The four clades associated with this study are labeled A, B, C, and D, as in figure 4.