Cerasommatidia arrowi

Arriaga-Varela, Emmanuel, Tomaszewska, Wioletta, Szawaryn, Karol, Robertson, James, Seidel, Matthias, Ślipiński, Adam & Fikáček, Martin, 2023, The resurrection of Cerasommatidiidae, an enigmatic group of coccinelloid beetles (Coleoptera: Coccinelloidea) based on molecular and morphological evidence, Zoological Journal of the Linnean Society 197 (4), pp. 1078-1115 : 1091

CERASOMMATIDIA ARROWI BRÈTHES, 1925

( FIGS 3A, F , 4A–G , 20B )

Cerasommatidia arroaei Brèthes, 1925: 201 . – Pakaluk et al., 1994: 228; Shockley et al., 2009: 27.

Material examined: Holotype, male, BRAZIL: Rio de Janeiro (Corcovado), 11.V.1912 // Cerasommatidia arroaei nov. spec. Brèthes ( BMNH).

Diagnosis: Cerasommatidia arroaei is most similar to C. plaumanni in overall appearance and by sharing the anterior bordering line of the pronotum disappearing medially ( Fig. 4B ). However, it can be distinguished from C. plaumanni by having the posterior margin of the pronotum not bordered and by the aedeagus regularly curved and possessing a much longer tegmen ( Fig. 3F ) than in C. plaumanni .

Description: Body: length 1.4 mm, 1.4 times as long as wide, 1.8 times as long as high, short oval and moderately convex, black with dark-brown legs, antennae and palpi ( Fig. 3A ).

Antenna nearly 0.35 of length of body; antennomeres 1–5 longer than wide; antennomeres 6, 7, 9 subquadrate and antennomere 8 slightly transverse.Apical labial palpomere short and subtruncate, 1.3 times as long as wide.

Pronotum 2.2 times as wide as long, 2.2 times as wide at widest part than at front angles ( Figs 3A , 4B ). Anterior margin with fine bordering line vanishing medially; lateral margins narrowly, gently bordered; base not bordered. Prosternal process with apex about 0.65 of width of procoxal cavity, narrowest near halflength, weakly widened apically, with raised lateral carinae, reaching almost apical quarter of prosternum, with central part between carinae slightly depressed.

Elytra 1.0 mm long, about as long a wide, 2.9 times as long and 1.2 times as wide as pronotum; lateral margins visible from above at basal two-thirds ( Fig. 4C ). Metaventrite with fine setiferous punctures ( Fig. 4E ). Mesoventral process about 1.1 times as wide as mesocoxal diameter ( Fig. 4E ).

Legs. Meso- and metatrochanters flattened, weakly angulately produced posteriorly.

Male genitalia ( Fig. 3F ). Aedeagus with penis long and comparatively narrow, sclerotized, curved, with simple apex. Tegmen large, submembranous, long; tegminal strut large, flattened, membranous.

Female unknown.

Distribution: Brazil ( Fig. 20B ).

Figures

Figure 3. Morphology of Cerasommatidia spp. A, Cerasommatidia arroaei holotype, dorsal habitus of dismembered specimen. B, Cerasommatidia plaumanni paratype, dorsal habitus. C–E, Cerasommatidia plaumanni: C, head, dorsal. D, meso- and metaventral structures. E, abdomen with male terminalia and genitalia partially visible through the abdominal ventrites. F, Cerasommatidia arroaei male genitalia. Scale bars: 1 mm.

Figure 4. Morphology of Cerasommatidia arroaei. A, head, dorsal. B, pronotum (arrow: posterior margin of pronotum). C, left elytron, dorsal. D, details of elytral surface. E, metaventrite. F, metatarsus. G, abdomen, ventral (arrow: postcoxal line).

Figure 20. Geographical distribution of Cerasommatidiidae spp. A, distribution of species in eastern Caribbean region. B, distribution of species in southeastern Brazil. C, distribution of species in Madagascar.