Prymnotomis cecidicola shares with the closely related Hexeretmis Meyrick the porrect maxillary palpi, forewing cleft only to 1/5 from termen, and pattern of wing venation. However, it differs from this genus in general appearance in coloration pattern and by presenting deeper hindwing clefts (ca 1/3 of wing length), as pointed out by Meyrick (1931). P. cecidicola can be separated from the congeneric P. crypsicroca Meyrick by the smaller size of the latter, whose forewing length of the type specimen measures ca 6 mm, and by the less contrasting coloration of P. crypsicroca, especially in relation to the hindwing. The basal process of the valva of the male genitalia is upturned, finger-like, covered with sparse filiform setae in P. crypsicroca, while in P. cecidicola it is turned down, looking like a claw, bearing short, stout spines on the base.

Description of adults (Figs 2–19). Male. Forewing length (mean ± standard error) = 9.34±0.45 mm; n = 6. Body with most scales greyish brown, interspersed by either isolated or small patches of either entirely light grey or bicoulored scales, mostly with whitish beige at the base and pale greyish brown at the apex (Fig. 2). Palpi and thoracic legs a little lighter at distal portion of each segment (Figs 7, 8). Abdominal segments also lighter ventrally. Head bearing paired tufts of scales on posterior vertex that project mesally, forming a collar (Fig. 6). Similar to description of P. crypsicroca provided by Meyrick (1931): maxillary palpus small; labial palpus well developed, porrected, with middle segment more than double the other two in length (Fig. 7); antennae filiform, reaching ca 2/3 forewings in length, with flagellomeres ventrally ciliated; forewings mostly dark grey; a wavy whitish line on costal edge marking alternate dark fuscous spaces; a short and fine whitish, transversal bar on end of cell; three wavy whitish parallel lines crossing the terminal lobes (Fig. 2), proximal one weakly defined, restricted to basal intersections (Fig. 3); fringe concolours with adjacent scales; hind wings mostly dark grey distally, with basal half whitish, densely permeated on base with dark grey scales (Fig. 4); three fine white wavy lines on lobes and associated fringes (Fig. 5), similar to description of forewings. Genitalia (Figs 9–16): Uncus narrow, downcurved near middle and spatulate (Figs 9, 11, 13), with distal margin showing medially a slightly developed, pointed process. Median arm of gnathos strait and flattened, with a bow-shaped, distal margin bearing filiform setae (Figs 9, 11, 14). Tegumen short, compact, rounded dorsally (Fig. 9). Juxta straight, narrow and flat, forked on both ends (Figs 11, 16) with a pair of long, cylindrical arms bearing minute and sparse setae on widened distal ends (Figs 11, 15). Valva membranous, with cucullus well developed, widened in distal half, bearing long filiform setae on distal, rounded margin; basal process well developed and sclerotized, claw-like, bearing a few stout spines on base (Figs 9–11). Aedeagus similar in length to valva, tubiform, slightly curved, bearing a pair of indistinctly shaped, sclerotized plates apically. Vesica with elongated and narrow plates of indistinct shape. Coecum penis ca two-thirds of total length of aedeagus (Figs 9, 12). Female. Virtually no differences from male regarding size and coloration. Genitalia (Figs 17–19): Papillae anales elongated, narrowly rounded apically, bearing sparse, long and short setae (Fig. 19). Eighth tergum broad with relatively long setae at distal on ventral margin. Posterior and anterior apophyses thin, similar to each other in length. Ostium bursae broad, opening near posterior margin of eighth sternum; antrum narrower, wide medially, slightly sclerotized on distal margin; ductus bursae membranous, wide medially, similar to anterior apophyses in length. Ductus seminalis inserted on distal third of ductus bursae. Corpus bursae membranous, ovoid, ca 2/3 ductus bursae in length, wall covered with minute microtrichea (Fig. 18), without signum.

Description of immature stages. Last instar larva (Figs 20–34, 51): Head capsule width (mean + standard error) = 1.88±0.01 mm; body length = 15.24+1.31 mm, n = 5. Body slightly cuneiform, proportionally wider in the middle abdominal segments (Fig. 20). Head tan-brown, with frontoclypeal area, labrum and mandibles darker (Figs 21–23, 51). Thorax and abdomen light yellow (Fig. 51), turning into reddish prior to pupation. Prothoracic shield slightly melanized, with faint patches of light brown spots located laterally. Anal plate and thoracic legs not melanized. Head: subrectangular, with lateral margins convex, semiprognathus; a sculptured area latero-dorsally on posterior margin (Figs 24, 27). Frontoclypeus subtriangular, with adfrontal sutures extending to apex of epicranial notch (Fig. 21). Five poorly developed, laterally located stemmata (Figs 22, 24). Labrum (Fig. 25) slightly bilobed, with three pairs of setae on distal margin, two pairs laterally on proximal margin and another pair mesally. Antenna (Fig. 26) 2-segmented; basal segment with five sensilla on distal margin, two short and stout, one minute, and two long with more than 3x the length of the others; distal segment much thinner and shorter, bearing one short sensilla on distal margin. Mandible well developed with four cusps along distal margin and two setae basally on external surface. Maxilla (Fig. 28) with palpus and galea well developed, stipes bearing well-developed flap-like, distally forked protrusions that project mesally (Fig. 29). Spinneret short, conical (Figs 28, 29). Labial palpus (Fig. 29) bi-segmented; distal segment thinner and much shorter, both with well-developed apical seta. Chaetotaxy (Fig. 20): MD group trisetose; F unisetose; C group bisetose; A group trisetose, with A1 longer than A2 and A3; AF group bisetose; S group trisetose, with S2 and S3 longer than S1; L unisetose, SS group trisetose. Thorax (T) and abdomen (A): Integument covered with microtrichia (Figs 30, 33, 34). Thoracic legs well developed (Fig. 30), with stout tarsal claw bearing a tooth on ventral basis (Fig. 31). Circular spiracles (Fig. 32) with slightly elevated peritreme, laterally on T1, and A1–8. Abdominal pseudopodia short (Figs 33, 34), on A3-6 and A10, with crochets arranged on uniserial and uniordinal, as a penellipse. Chaetotaxy (Fig. 20): T1 with D, XD and SD group bisetose, all on the dorsal shield; D2 longer than D1; XD similar to each other in length; SD2 shorter than SD1; L group bisetose, both on the same pinacula, with L1 shorter and latero-dorsal to L2; SV bisetose, with SV1 shorter than SV2. T2-3 with D group bisetose, similar to prothorax; SD bisetose; L1 trisetose, with L1-2 anterior to L3, and posterior to SD; SV and V unisetose. Abdominal segments (A) with only short setae that are more or less aligned on the middle region of each segment, which are herein tentatively named. A1 with D and L groups bisetose; SD and SV unisetose; V present. A2 with D and L groups bisetose; SV trisetose; SD unisetose; V present. A3-6 with D and L groups bisetose; SD unisetose; SV trisetose, with SV2 and SV3 on proleg; MV3 and V present. A7-9 with D, SV and L groups bisetose; SD unisetose; MV3 and V present. A10 with D and SD groups bisetose, located within the anal plate; L bisetose; SV trisetose; V present.

Pupa (Figs 35–48). Body cylindrical, yellowish brown, mean length (± standard error) = 9.6 ± 1.74 mm; maximum width = 4.08 ± 0.07 mm; n = 5. Head with vertex deprived of setae and without a differentiated gall-cutter (Figs 38–41). Frons wide, posteriorly expanded mesally to the eyes. Clypeus subtrapezoidal, also without setae. Antennae filiform, reaching the distal end of the middle legs. Mandibles small, rounded, latero-posterior to the clypeus. Maxillary palpi small, rounded, latero-posterior to the eyes. Proboscis well developed, reaching A2. Prothorax fairly developed, deprived of setae, bearing postero-laterally a wide open spiracle (Fig. 43). Hindwings concealed by forewings; the latter with six well marked longitudinal lobes on external surface (Fig. 44), extending to sixth abdominal segment. Protho-, meso- and methatoracic legs reaching the third, fifth, and seventh abdominal segments, respectively. Thoracic and abdominal setae extremely reduced in size (Fig. 45); one pair dorsally on mesothorax and A1; two pairs of such setae on metathorax and A2-7, one dorsal and the other lateral, dorsally to spiracles. Abdominal spiracles rounded, with slightly elevated peritreme (Fig. 46), laterally on A2–7; spiracle on A8 partially closed (Fig. 47). Distal margin of the last abdominal segment with six pairs of stout, distally hooked setae (Fig. 48).

Material examined. All specimens examined came from galls associated with Cordiera elliptica (Cham.) Kuntze (Rubiaceae) at Embrapa Cerrados, as already described. Adults were reared by V.O. Becker, from galls collected during October 1982-83 (LMCI 313 series). Immatures were either dissected or reared by C.M. Pereira and A. Specht, from galls collected by C.M. Pereira (LMCI 349 series) on 19.x.2018. Additional galls were collected by G.R.P. Moreira & J. Fochezato (LMCI 346 series) on 1-4.xii.2018.

Holotype male, BRAZIL: DF, Planaltina, 1100 m, 14.i.1985, ex Cordiera elliptica (Cham.) Kuntze (Rubiaceae) (Becker, 57100) (VOB). Paratypes: 11 males, 4 females, 3.xii.1984-8.i.1985, same data as holotype; 1 female, same data as holotye, but 20.ii.1976, at light (Becker, 19564); 2 male, 1 female, same data as holotype, but 15-30.xii.1982 (Becker, 40740); 1 male, same data as holotype, but 15.x.1982, at light (Becker, 40613); 11 males, 1 female, same data as holotype, but 14.xi-23.xii.1983, at light (Becker, 41731); 1 male, same data as holotype, but 5.i.1984, at light (Becker, 56053). Additional paratypes, same data as holotype: 3 male (VOB 57100, 3.xii.1984, deposited LMCI 313-869; VOB 41731, 26.xii.1983, deposited at LMCI 313-874; LMCI 313-879/VOB 40740, donated to DZUP/DZ 33.402), and 3 ♀♀ (VOB 57100, 19.xii.1984, deposited LMCI 313-870; VOB 41731, 5.xii.1983, deposited at LMCI 313-876; VOB 41731, 14.xii.1983, donated to DZUP/DZ 33.412).

Additional material examined, not type specimens: 1 female, GO, Ipameri, 10.X.1988 (Becker, 59682); MG, Nova Lima, 850m: 2 males, 25-27.xii.1982; 2 males, 1-10.i.1985; 1 female, 30.xii.1988; all at light (Becker, 50290, 55772, 60523) (VOB, USNM, NHMUK). Pinned-dried adults with genitalia preparations mounted in Canada balsam on slides – 2 males (VOB 40740, 17.i.1983, deposited at LMCI 313-867; VOB 40740, 15.xii.1982, deposited at LMCI 313-880); 2 females (VOB 57100, 6.xii.1984, deposited at LMCI 313-872; VOB 40740, 30.xii.1982, deposited at LMCI 313-878). Immatures fixed in Dietrich’s fluid and preserved in 70% ethanol – three last instar larvae (VOB 1519, 2.x.1984, deposited at LMCI 313-865A); five pupae (VOB 1519, 2.x.1984, deposited at LMCI 313-865B); twelve mature galls (CMP 008-01, donated LMCI 349-1); five empty, senescent galls (LMCI 346-01). Also, two last instar larvae, preserved in 100% ethanol at -20 °C, used for DNA extraction (CMP 008-04, donated to LMCI 349-2). Two last instar larvae preparations, also mounted in Canada balsam on a slide (VOB 1519, donated to LMCI 313-865C).

Other species examined (pinned-mounted adults): Prymnotomis crypsicroca Holotype male, BRAZIL: ES, [Baixo] Guandú, ES, 1920 (Hoffmann) (NM, Vienna) (g.s. NM 13322). Hexeretmis pontopora Meyrick, 1??? Holotype males, BRAZIL: PA, Taperinha, 11-20.vi.1927 (Zerny) (NM, Vienna) (g.s. NM 13321. Alinguata neblina Fleming, Alotype male, VENEZUELA: [Aragua], Rancho Grande, 3.vii.1946 (Fleming) (AMNH) (g.s. VOB).

Distribution. Prymnotomis cecidicola is known from the Brazilian Savanna, within the biome called “Cerradão” (= Cerrado stricto sensu; for a description, see Parron et al. 1998) where their host-plant and associated galls were found. The adults of this species do not come readily to light, as shown by the few specimens studied. The third author collected all over the Cerrado region of Brazil for over 30 years. At the type locality (Planaltina) he collected this species regularly in places very close to the host plant where the galls were common.

Host plant. Galls of P. cecidicola have been found only in association with Cordiera elliptica (Cham.) Kuntze (Rubiaceae) (Fig. 49), a plant native to the Brazilian Savanna (Cerrado Biome), with distribution ranging from northeast Bahia to southeast São Paulo state. It is a dioecious shrub (1.5 to 3.0 m high), with thin, cylindrical, glabrous branches, having dimorphic inflorescences; these are fasciculate on male plants, but only solitary flowers appear on female ones (Matsuoka LG, UFG, unpublished data). Also according to this author, flowers appear during the dry season (from July to September), fruits maturing later on, during the peak of the rainy season (from November to December), which was confirmed by our field observations. At the type locality, C. elliptica is commonly known as “marmelinho” and “marmelada-de-pinto”, being found scattered on vegetation, particularly along trails. The fruits are consumed by native people either fresh or as a home-made jelly.

The species name is derived from the Greek kekis – idos = gall + the Latin co – col = with; to be treated as feminine.

Mature galls of P. cecidicola (Figs 50–53) measure on average (± standard error) 1.80 ± 0.34 cm (n = 5) in diameter. They are green when active, spherical, unilocular and develop individually on C. elliptica inflorescences of both male and female plants. Thus we infer they are induced early on flower buds, since male flowers are dehiscent. Cordiera elliptica fruits are also green and spherical during development, but a little smaller (maximum diameter = 1.49±0.14 cm; n = 5) and turn brown when mature (Fig. 55). Contrary to P. cecidicola galls that have a smooth surface, C. elliptica fruits show conspicuous style scars distally (Fig. 50). Empty galls of P. cecidicola dry up, turning black, remaining attached to the plant (Fig. 56).

Larvae of P. cecidicola assume an arched position within their galls by placing the body around the fecal pellets left inside the gall. These are packaged and positioned centrally, as a sphere, firmly attached to the gall wall (Fig. 51), except when leaving the gall, when fecal pellets are left aside (Fig. 53). This sphere also contains the larval exuviae packaged within the feces. It is apparently increased in size and modelled periodically, being covered each time by a fine, blackish, silk net.

The body of full-grown P. cecidicola larvae progressively changes to red before pupation, when they leave the gall through a circular orifice made laterally on the gall wall (Fig. 52). Invariably when offered sandy soil and dried-broken leaves at the bottom of the rearing plastic pots in the laboratory, they built a flat, semi-rectangular, tied, silk-woven cocoon with debris attached (Fig. 54). Exit orifices were present on the surface of empty galls found in the field. Since we did not encounter cocoons attached to the host plant bearing empty galls under these conditions, we presume pupation occurs in the litter, which should be explored further.

Cordiera elliptica plants bearing galls of P. cecidicola were found scattered in the field, density varying from one to four galls per plant. Field collections suggested that at the type locality P. cecidicola is a univoltine species. Galls and associated larvae were noticeable during the end of the dry season (August) up to beginning of the rainy season (October), thus coinciding in phenology with the reproductive phase of the host plant, described above. Full-grown larvae and pupae were obtained in late October. Emergence of adults under laboratory conditions was recorded from November to January.

Figures 2–8. 

Pinned-dried adult of Prymnotomis cecidicola sp. nov. (2) dorsal view, and corresponding morphology (3–7) in detail: (3) right forewing apical angle (indicated by rectangle in Fig. 2); (4) left hind wing discal cell area (marked by asterisk in Fig. 2); (5) right hind wing outer margin (delimited by brackets in Fig. 2); (6,7) head in dorsal and lateral views, respectively; (8) left hind leg, anterior view. Scale bars: 2.5, 1, 1, 1, 0.5, 0.5, 2 mm, respectively.

Figures 9–16. 

Male genitalia morphology of Prymnotomis cecidicola sp. nov. under light microscopy: (9, 11) general, lateral and ventral views, respectively (aedeagus omitted in Fig. 11); (10) valva, lateral (area marked with rectangle in Fig. 9); (12) aedeagus, lateral; (13) apex of uncus, ventral (indicated by asterisk in Fig. 11); (14) distal portion of gnathos (pointed by open arrow in Fig. 11); (15) arms of juxta, lateral (indicated by closed arrow in Fig. 11); (16) base of juxta (pointed by seta in Fig. 11). Scale bars; 200, 100, 200, 200, 100, 100, 70, 100 µm, respectively.

Figures 17–19. 

Female genitalia morphology of Prymnotomis cecidicola sp. nov. under light microscopy: (17) general view, ventral; (18, 19) detail of corpus bursae and papillae anales, respectively (areas marked with rectangles in Fig. 17). Scale bars: 200, 30, 50 µm, respectively.

Figures 20–23. 

Last larval instar of Prymnotomis cecidicola sp. nov. under light microscopy: (20) chaetotaxy, lateral view; (21–23) head under dorsal, ventral and lateral views, respectively. Scale bars: 1 mm; 100, 100, 100 µm, respectively.

Figure 24–34. 

Morphology of Prymnotomis cecidicola sp. nov. last larval instar under scanning electron microscopy: (24) head, lateral view; (25) labrum, dorsal; (26) antenna, lateral; (27) latero-dorsal area of head in detail; (28) maxillae and labium, antero-ventral; (29) labium in detail (area marked by rectangle in Fig. 28; asterisk indicates associated flap-like protrusions of stipes); (30) mesothoracic leg, postero-lateral; (31) tarsal claw in detail, posterior (open arrow indicates basal spine); (32) prothoracic spiracle, lateral; (33) proleg of fifth abdominal segment, lateral; (34) last two abdominal segments, lateral. Scale bars: 200, 50, 50, 50, 100, 25, 100, 25, 50, 50, 200 µm; 0.5, 0.5, 0.5 mm, respectively.

Figures 35–37. 

Prymnotomis cecidicola sp. nov. pupa under light microscopy, in dorsal (35), ventral (36) and lateral (37) views. Scale bar: 0.5 mm.

Figure 38–48. 

Morphology of Prymnotomis cecidicola sp. nov. pupa under scanning electron microscopy: (38–40) head, under dorsal, ventral and lateral views, respectively; (41) vertex of head, anterior; (42) buccal appendages, ventral; (43) prothoracic spiracle, dorsal; (44) left forewing, lateral; (45) mesothoracic seta, dorsal; (46, 47) fourth and eight abdominal spiracles, respectively, lateral; (48) dorsal hooks of last abdominal segment, lateral. Scale bars: 500, 100, 200, 100, 500, 25, 50, 50, 50 µm, respectively.

Figure 49–56. 

Natural history of Prymnotomis cecidicola sp. nov. on C. elliptica: (49) host plant at the type locality; (50) young fruit and gall on female plant (gall is marked by asterisk; closed arrow indicates style scar of the fruit); (51) dissected gall showing last instar larva (seta indicates sphere made of faeces and exuviae attached to the gall wall); (52) external aspect of empty gall, showing larval exit orifice (pointed by open arrow); (53) dissected empty gall, showing sphere of packaged faeces and exuviae with fecal pellets left aside (pointed by closed arrow) by the larva before leaving for pupation; (54) fresh cocoon made by last larval instar in association with sand grains and dead-broken leaves under laboratory conditions; (55) mature fruit; (56) senescent empty gall. Scale bars: 3, 3.5, 4, 1, 3.5, 3.5 mm, respectively.