Neopleurophora

Ament, Danilo Cesar & Amorim, Dalton De Souza, 2013, Taxonomic revision of the genus Neopleurophora Brown (Diptera: Phoridae), with the description of thirty seven new species, Zootaxa 3657 (1), pp. 1-93 : 68-75

Neopleurophora synapomorphies

Neopleurophora was originally erected based on two synapomorphies ( Brown, 1992), which do not apply to all the species herein described:

(1) Hypandrium with elongated process on left lobe. This can be understood in Brown’s illustrations as left lobe of hypandrium enlarged (1992, fig. 23B). Most species herein described have a large left lobe of the hypandrium, even though there are some few exceptions, as N. dichaeta and N. synaptodrilus . Large left hypandrial lobe can also be found in outgroups, such as Mannheimsia .

(2) Hypandrium with anterior left lateral process. This process was not observed in some species described here (e.g., N. odontopyga , N. acrochaetopyga and N. tanytarsus ), and in many of them it is not a conspicuous process.

With the addition to the genus of the species described here, these features remain as synapomorphies, but probably supporting less inclusive clades within the genus. It is proposed here as Neopleurophora synapomorphies the hypopygial anterior protrusion of the left epandrial posterior margin, usually bearing a thin membrane, and a rotation of 90º of the hypopygium.

Brown’s (1992) hypothesis of surstilar fusion and shift

In the reconstruction of the phylogenetic relationships between the Phorinae genera by Brown (1992), great part of the phylogenetic resolution comes from a transformation series of the surstyli that was ordered a priori. One of the groups supported by this feature is a clade gathering Neopleurophora + Chaetocnemistoptera + Plethysmochaeta + Coniceromyia .

Given the importance of the homology of the surstyli conditions for the subfamily phylogeny and the possibility that different codification schemes can be constructed for these conditions, the status of the relationships of Phorinae genera should be at least for the time considered doubtful. Other characters should be used to test the resulting clades, so a robust phylogenetic hypothesis for the subfamily can be obtained. New characters have been recently studied, such as molecular data (Brown, pers. com.) and detailed hypopygial morphology ( Ament, 2012; Nakayama, 2012) that certainly will add up to the understanding of the relationships between the genera of the subfamily.

Outgroup comparison and the morphological variation in Neopleurophora

Some features show considerable variation between Neopleurophora species as well as between species belonging to other genera within the Phorinae . The difficulty in treating these characters is aggravated as there is no clear resolution of the genera closely related to Neopleurophora , as commented above. Therefore, outgroup sampling can influence greatly the states optimization within Neopleurophora . Important characters for the taxonomy of the genus that can suffer from this outgroup sampling bias are:

(1) The mid/hind tibial chaetotaxy. Neopleurophora species generally present an increased number of mid and hind tibial setae, in comparison to other Phorinae genera. Some species of Chaetocnemistoptera , Plethysmochaeta and Chaetopleurophora , however, present a similar chaetotaxy in these tibias, what can put into question the apomorphic condition of the presence of many tibial setae in Neopleurophora .

(2) Bifurcation of the epandrial medial process. The epandrial medial process can be either bifurcated or nonbifurcated among Neopleurophora species. Both conditions are also found in the genera Chaetocnemistoptera , Plethysmochaeta and Coniceromyia .

(3) Hypoproct number of setae. Neopleurophora species can have two to 13 hypoproct setae. The outgroup genera generally have two hypoproct setae, but there are also the exceptions as Coniceromyia with 2–4 setae, Kuenburgia bifurcata with four and Rhynchomicropteron with six setae.

Perspectives

The Neopleurophora leg chaetotaxy and epandrium, hypandrium and phallic morphology seem to be congruent in many grouping proposals within the genus. Although this provides the first clues in the Neopleurophora species relationship, the taxonomy of the genus still warrants outgroup phylogenetic resolution so correct states optimization can be made within Neopleurophora .

This study dealt with a large quantity of material collected from many localities of the Neotropical Region revealing a large number of undescribed species. The real diversity of the genus, however, may be much higher than this, as indicated by the high number of Neopleurophora singletons— species only known from a single specimen.