TERMITOXENIINAE, Wasmann, 1901

Brown, Brian V., Amorim, Dalton De Souza & Kung, Giar-Ann, 2015, New morphological characters for classifying Phoridae (Diptera) from the structure of the thorax, Zoological Journal of the Linnean Society 173 (2), pp. 424-485 : 454

TERMITOXENIINAE + ( PHORINAE + METOPININAE )

21. Vein M 1: (0) basally terminating posterior to R 4+5, (1) appearing to be attached to R 4+5 ( Fig. 13A–H ).

Most phorids, except chonocephalines, have the base of vein M 1 appearing to be attached to, or arising from, vein R 4+5.

22. Ventral third of anepisternum: (0) microtrichose, like dorsal two-thirds (1) bare, shiny ( Fig. 14A–F ).

The entire anepisternum is covered with microtrichia in Platypezidae ( Figs 2, 14A ), Ironomyiidae , Lonchopteridae ( Figs 3, 14B ) and Sciadocerinae . Both genera of Chonocephalinae ( Fig. 14C ) have the anepisternum partly covered with microtrichia and we have coded this condition as 0. Most Termitoxeniinae ( Fig. 14D ) (but not Javanoxenia ) and remaining phorids ( Fig. 14E, F ) have a characteristically shiny area on the ventral third of the anepisternum. This feature also indicates in Figure 48 below that the Termitoxeniinae would be sister to the Metopininae + Phorinae .

23. Midcoxa anterodorsally: (0) rounded, (1) broadened, squared ( Fig. 28A–F ).

There seems to be some secondary changes in the shape of the midcoxa among phorine genera (and, hence, some reversions in the subfamily), but this feature defines an important clade including hypocerines, diplonevrines and other genera, but not Aenigmatias .

24. Midcoxa posterodorsally: (0) with edge inclined, distance from attachment dorsally and posterolateral suture short, (1) extending posteriorly, distance from attachment dorsally to posterolateral suture long ( Fig. 28A–F ).

The dorsal end of the midcoxa in the Diptera groundplan articulates to the midcoxifer, ventrally at the end of the mesopleural suture, which marks the limit between the katepisternum and the anepimeron (or to the meron, in the dipteran groups in which this sclerite is part of the pleura). The changes we can see in this part of the phorid mesopleuron involve the shape and articulation of the midcoxa on the thorax. In Platypezidae ( Fig. 28A ), Lonchopteridae ( Fig. 3) and sciadocerines ( Fig. 28B ), the coxa is slender, pointed dorsally, connecting to the suture between the katepisternum and the meron. In these groups, the base of the coxa is roughly symmetric, with both anterior and posterior edges mirroring each other. A parallel change is possibly the shape of the anterior margin of the meron. In platypezids, sciadocerines and Chonocephalus , the anterior margin of the meron is gently curved anteriorly ( Fig. 28A–C ), while in most other phorids there is an angle at the anterior margin of the meron ( Fig. 28D–F ). The anterior and posterior edges of the midcoxa basally evolved independently, and therefore the modifications are coded as two separate characters. In Chonocephalus ( Fig. 5 ), most Termitoxeniinae , some Metopininae and some Phorinae , the plesiomorphic shape is more or less conserved, although slightly more rounded than the pointed coxae of outgroup families coded here as 23(0) and 24(0). In some phorines and some metopinines, the anterodorsal margin is more squared (character 23), and in some phorines the margin between the dorsal attachment and the posterior lateral suture is greatly enlarged (character 24). The derived state of both these characters is found in a group of higher phorines defined by several other characters in this analysis (see below). Indeed, within the Metopininae and the Phorinae , some other character states are found. In the basalmost metopinine genus, Ctenopleuriphora , for example, both of the primitive states are found, suggesting that some of the derivations within the Metopininae are not homologous with those in the Phorinae . As we are not concerned with analysis within the Metopininae in this paper, we set aside the character states in Metopininae and encode them all as non-comparable. There are other changes in the upper posterior part of the midcoxa in some phorine genera. This will be dealt with by us at a later date. For now, it comes out as a homoplasy between Coniceromyia and related genera in a small clade, and hypocerines, including Hirotophora gen. nov. and Neopleurophora .

Figures

Figure 5 SEM of thorax of Chonocephalus (Phoridae, Chonocephalinae), lateral view.

Figure 13 Characters 4 and 7. Character 4 (black arrows). R4+5 ending at wing tip (0); R4+5 ending before wing tip (1); R4+5 at most at distal one-third of wing length (2). Character 7 (grey arrows). R1 reaching at least distal third of wing (0); R1 reaching distal half of wing (1); R1 reaching basal third of wing (2). A, Lindneromyia. B, Lonchoptera. C, Sciadocera. D, Chonocephalus. E, Pseudacteon. F, Coniceromyia. G. Latiborophaga. H, Trophithauma.

Figure 14 Characters 5 and 22. Character 5 (white arrows). Katepisternum and anepisternum continuous (0); with a furrow separating anespisternum from katepisternum (1); with furrow almost reaching ventral margin of thorax (2). Character 22 (black arrows). Ventral third of anepisternum microtrichose (0); ventral third of anepisternum bare (1). A, Callomyia. B, Lonchoptera. C, Chonocephalus. D, Termitophilomyia. E, Gymnophora. F, Latiborophaga.

Figure 28 Characters 23 (white arrows) and 24 (black arrows). Character 23. Midcoxa anterodorsally rounded (0); squared (1). Character 24. Midcoxa posterodorsally with distance between dorsal attachment and posterolateral suture short (0); long (1). A, Plesioclythia. B, Sciadocera. C, Chonocephalus. D, Beckerina. E, Coniceromyia. F, Latiborophaga.

Figure 48 Strict consensus of the six most-parsimonious trees of implied weight analysis of the data matrix in Table 3. Only unambiguous characters are optimized. Character states 0 and 2 indicated, otherwise state = 1. Black circles correspond to characters with single origin in the analysis, open circles correspond to characters with more than one step in the analysis.