Ceratocista Gustafsson & Bush, new genus

Brueelia Kéler, 1936a: 257 (in partim).

Type species. Brueelia antennatus Ansari, 1956a: 139

Diagnosis. Ceratocista n. gen. (Figs 153–160) is most similar to Resartor n. gen. (Figs 161–167), and these two genera share the following characteristics: pos and pns absent; tps absent in both sexes; marginal carina interrupted only submedianly and displaced section at osculum forms nail-like thickening of dorsal anterior plate; female subgenital plate flares into medianly displaced cross-piece; proximal mesosome slender; parameral blades slenderly triangular, somewhat extended distally; female tergopleurite IX+X fused with tergopleurite XI; sternal plate VI of both sexes with 2 sts. However, antennae are sexually dimorphic in Ceratocista (Figs 155–156) but not in Resartor (Fig. 163), and while ss are present on male tergopleurites II–VIII in Resartor (Fig. 161), these are present only on tergopleurites VII–VIII in Ceratocista (Fig. 153). In both genera the mesosomal lobes are extended laterally to overlap dorsally with the parameres, but Resartor (Fig. 165) does not have the large postero-lateral brush-like extensions of these lobes found in Ceratocista (Figs 157–158), nor are the antero-lateral triangular sections of the lobes found in Ceratocista present in the male genitalia of Resartor . The frons is clearly hyaline in Resartor (Fig. 163), whereas in Ceratocista it is pale but apparently sceloritzed but translucent (Fig. 155). Ventral anterior plate absent in Resartor (Fig. 163) but present in Ceratocista (Fig. 155).

The lateral extensions of the mesosomal lobes in Ceratocista are similar to those found in Psammonirmus n. gen. (Fig. 150), but the differences between these two genera are substantial, and have been listed under Psammonirmus .

Description. Both sexes. Head narrow, concave-dome shaped (Fig. 155). Marginal carina broad, interrupted submedianly. Displaced section forms nail-like marginal carinal plate at osculum, delimited posteriorly by sinuous ridge. Dorsal preantennal suture arises from interruptions of marginal carina, not medianly continuous and not reaching ads or dsms. Ventral carinae with finger-like median protrusion; carinae diffuse anterior to pulvinus. Ventral anterior plate present. Head setae Fig. 155; avs2 much shorter than avs3; pos and pns absent. Antennae sexually dimorphic, with male scape (Fig. 155) much elongated and thicker than female scape (Fig. 156). Temporal carinae not visible; mts 3 only macrosetae. Gular plate roughly triangular.

Prothorax rectangular (Figs 153–154); ppss on postero-lateral corner. Proepimera hammer-shaped medianly. Pterothorax pentagonal; lateral margins divergent and posterior margin convergent to median point (Figs 153–154). Meso- and metasterna not fused, one seta on postero-lateral corner on each side of each plate. Metepisterna hammer-shaped medianly. mms moderately interrupted medianly. Leg chaetotaxy as in Fig. 25, except fI-p2, fI-v4 absent.

Abdomen (Figs 153–154) broadly oval, much stockier in male than in female. Terminal end of abdomen rounded in male, deeply divided in female. Abdominal chaetotaxy as in Table 2. Tergopleurites II–IX+X in male and tergopleurites II–VIII in females narrowly divided medianly, rectangular, but more posterior tergopleurites in males triangular. Female tergopleurite IX+X fused to tergopleurite XI. Sternal plates medianly continuous, rectangular, approaching but not reaching pleurites. Pleural incrassations with dorsal and ventral median margins. Re-entrant heads moderate to large. Male subgenital plate triangular with lateral indentation on segment IX+X. Female subgenital plate trapezoidal (Fig. 160), reaching vulval margin where it flares into a medianly displaced cross-piece.

Male genitalia as in Figs 157–159. Proximal mesosome slender, elongated. Gonopore open only distally. Mesosomal lobes large, overlapping with parameres dorsally, fringed on distal margin. 3 ames anterior to gonopore. Parameral heads blunt, with accessory sclerite. Parameral blades slenderly triangular; pst1–2 both sensilla, submarginal.

Host distribution. Ceratocista is presently known only from a single host species of the genus Grammatoptila Reichenbach, 1872, in the family Timaliidae .

Geographical distribution. Presently known only from South Asia.

Etymology. Ceratocista is formed by Greek “ kérato ” for “horn” and Latin “ cista ” for “chest”, referring both to the box-shaped head and the prominent male antennae (Fig. 155) of the only known species of this genus. Gender: feminine.

Included species

* Ceratocista antennata (Ansari, 1956a: 139) n. comb. [in Brueelia]