Coelho Beatriz W T, Engel Michael S
Museu Paraense Emílio Goeldi, Campus de Pesquisa-CZO (Entomologia), Av. Perimetral, 1901-Terra Firme, Belém, Pará, PA 66077-830, Brazil..
Zootaxa. 2018 May 1;4415(3):513-532. doi: 10.11646/zootaxa.4415.3.6.
Males of the neotropical bee genus Ruizantheda Moure sensu lato (Halictinae: Caenohalictini) differ from those of other caenohalictine genera in having the outer gonostylar plate with a large membranous region that extends to the ventral region, and the ventral gonostylar lobe retrorse. These features permit the placement of six additional species described here, four of which are new, in the genus in this broader sense. The males of these six species share the following characteristics: profemur swollen; mesofemur exceedingly swollen; mesotibia slightly swollen with flat, minutely ridged ventral area and small apical tooth; S4 shortened medially, commonly largely hidden under S3, with transverse median depression and apical margin emarginate; apicolateral lobes of S4 with tuft of branched setae and stout, simple, recurved setae on margin; S5 with U-shaped gradulus and setal patch, sometimes inconspicuous; outer lateral expansion of penis valve bilobed, and median posterior margin of volsella strongly angulate. Together, these species constitute a new group within Ruizantheda and share with the previously known Ruizantheda inca Coelho, Felizardo, Engel, R. aerugineus Coelho, Felizardo, Engel, and R. kallos Coelho, Felizardo, Engel, a short outer gonostylar plate, terminating before the apex of the main gonostylar lobe as well as the presence of long setae on its dorsal surface. In other species of Ruizantheda the outer gonostylar plate extends beyond the apex of the main gonostylar lobe and lacks setae. The species comprising this distinctive subgroup of Ruizantheda, and treated herein, are: R. nigra n. sp., R. colombiana n. sp., R. venezuelana n. sp., R. baeri (Vachal) n. comb., R. pilosa n. sp., and R. gaullei (Vachal) n. comb. Two of the new species expand the distribution of the genus northward into Colombia and Venezuela. In addition to the description and illustration of the species, an updated key to the species of Ruizantheda s. l. is provided.
新热带地区蜜蜂属Ruizantheda Moure广义上（隧蜂亚科：新隧蜂族）的雄性与其他新隧蜂族属的雄性不同，其外生殖突板有一个大的膜质区域延伸至腹侧区域，且腹侧生殖突叶向后。这些特征使得在此处描述的另外六个物种（其中四个是新物种）能归入这个广义的属中。这六个物种的雄性具有以下共同特征：前足股节肿胀；中足股节极度肿胀；中胫节稍肿胀，腹侧区域扁平、有细微的脊且有小的顶端齿；S4在中部缩短，通常大部分隐藏在S3下方，有横向的中凹陷且顶端边缘有缺刻；S4的顶端外侧叶有一束分支刚毛且边缘有粗壮、简单、弯曲的刚毛；S5有U形的渐变带和刚毛斑，有时不明显；阳茎瓣的外侧扩展呈双叶状，且阳茎基腹片的后缘中部强烈成角。这些物种共同构成了Ruizantheda属内的一个新类群，并与先前已知的Ruizantheda inca Coelho、Felizardo、Engel、R. aerugineus Coelho、Felizardo、Engel以及R. kallos Coelho、Felizardo、Engel共享一个短的外生殖突板，该板在主生殖突叶的顶端之前终止，且其背表面有长刚毛。在Ruizantheda属的其他物种中，外生殖突板延伸至主生殖突叶的顶端之外且没有刚毛。构成Ruizantheda这个独特亚组且在此处进行处理的物种有：R. nigra新种、R. colombiana新种、R. venezuelana新种、R. baeri (Vachal)新组合、R. pilosa新种以及R. gaullei (Vachal)新组合。其中两个新物种将该属的分布范围向北扩展到了哥伦比亚和委内瑞拉。除了对这些物种的描述和图示外，还提供了Ruizantheda广义上的物种的更新检索表。
