Trouessartia cacica, Hernandes, 2023

Hernandes, Fabio Akashi, 2023, Feather mites (Acariformes: Astigmata) from the yellow-rumped cacique, Cacicus cela (Linnaeus, 1758) (Passeriformes: Icteridae) in Brazil, with description of four new species, Journal of Natural History 57 (2), pp. 257-284 : 269-274

publication ID 10.1080/00222933.2023.2174459


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scientific name

Trouessartia cacica

sp. nov.

Trouessartia cacica sp. nov.

( Figures 7 View Figure 7 –9,13(b))

Type material

Holotype male (#5398), paratypes 2 females (#5399–5400) ex Cacicus cela (Linnaeus, 1758) ( Passeriformes : Icteridae ), BRAZIL, Bahia State, Ilhéus, campus of UESC, 14.7597222°S, 039.2302778°W, found dead, 14 December 2020, Anibal R. Oliveira coll GoogleMaps . Paratypes 1 male and 2 females (#5401–5403), same host species, BRAZIL, Pará State, Fazenda Fartura, 9.666667°S, 50.383333°W, Santana do Araguaia, dead after collision with glass window, 11 September 2013, David V. Boas-Filho coll. (#557); 1 female (#5404), same host species, BRAZIL, Amazonas State, Lago Cumapi, Jap#754 (E3), 31 July 2007, Jason Weckstein coll.


Male ( Figures 7 View Figure 7 (a,b), 9 (a–9,f), 13(b)), holotype (measurements for 1 paratype in parentheses). Length of idiosoma from anterior end to bases of setae h3 470 (455), greatest width of idiosoma at level of setae d1 211 (214). Length of hysterosoma from sejugal furrow to bases of setae h3 296 (283). Prodorsal shield: length along midline 152 (146), greatest width posterior to scapular setae 147 (141), lateral margins sinuous, with two concavities at the level of trochanters II and posterior level of scapular shields, antero-lateral extensions roughly angular, not extending to bases of epimerites Ia between legs I and II, lateral margins not fused with scapular shields, posterior angles acute, surface smooth, posterior margins and angles distinctly darker ( Figure 7 View Figure 7 (a)). Vertical setae ve represented by alveoli. Internal scapular setae si thin setiform, 24 (25) long, separated by 60 (62); external scapular setae se 135 (161) long, separated by 100 (98). Humeral shield with setae c2 thin, setiform, 41 (39) long. Setae c3 lanceolate, without subapical tooth, 18 (17) long. Prohysteronotal and lobar shields not split, delimited from each other by transverse bow-shaped fold. Prohysteronotal shield: length 205 (201), greatest width at level of setae humeral shields 141 (136), lateral margins roughly sinuous, with shallow concavities at level of setae d2, dorsal hysterosomal apertures (DHA) absent, surface smooth, all borders distinctly darker than central area. Dorsal setae d1, d2 present, minute. Setae h1 inserted dorsally between setae ps2 and h2. Length of lobar shield excluding lamellae 75 (81). Opisthosoma attenuate posteriorly; opisthosomal lobes fused to each other along midline forming a sclerotised median septum, with only apical parts of lobes posterior to setae h2 separated by narrow parallel-sided terminal cleft, length of cleft from anterior end to apices of lamellae 34 (38), width in anterior part 10 (9). Lamellae semicircular, margins smooth, length from bases of setae h3 to lamellar apices 18 (17). Setae h2 302 (324) long, setae h3 137 (181) long. Distance between levels of dorsal setae and setal pairs: c2:d2 81 (85), d1:d2 56 (46), e1: e2 47 (43), e2:h2 74 (74), h2:h3 19 (20), h2:h2 39 (33), h3:h3 36 (33).

Epimerites I free. Rudimentary sclerites rEpIIa present, large, irregularly shaped, with a small lacuna inside. Humeral shield ventrally fused with epimerites III. Genital apparatus situated between levels of trochanters III and IV, length 34 (35), greatest width 14 (13) ( Figures 7 View Figure 7 (b), 9(f)), aedeagus short, anterior tip tapering. Epiandrum present, small, rounded, situated at level of anterior pair of genital papillae. Postgenital plaque present, semicircular; setae g thin, filiform, with bases not touching each other. Epimerites IVa present, their anterior level not reaching the level of setae g. Adanal apodemes as mild ridges posterolateral to the adanal suckers. Translobar apodeme present. Setae ps3 inserted on small triangular adanal shields anterior to adanal suckers. Adanal suckers 13 (15) in diameter, distance between centres of discs 21 (24). Setae 4b situated posterior to level of setae 3a, setae g and 4a roughly at the same transverse level. Distance between ventral setae: 4b:3a 12–9, 4b:g 77–76, g:ps3 67:65, ps3:ps3 32–38.

Legs IV with ambulacral disc extending to apices of terminal lamellae. Setae sR of trochanters III lanceolate, with acute apex, 14 (13) long. Modified setae d of tarsus IV barrel-shaped, with discoid cap, situated at distal half of the segment; modified setae e hemispheroid, without cap, situated apically ( Figure 9 View Figure 9 (d)). Length of solenidia: σ of genu I 47 (43), σ of genu II 9 (11), σ of genu III 21 (18), φ of tibia I 65 (66), φ of tibia II 69 (74), φ of tibia III 56 (55), φ of tibia IV 28 (29), ω1 of tarsus I 15 (19), ω3 of tarsus I 32 (36), ω1 of tarsus II 19 (19).

Female ( Figures 8 View Figure 8 (a–), 9 (e), 13(b)), range for 5 paratypes. Length of idiosoma from anterior end to apices of lamellar lobar processes 526–548, greatest width 210–234. Length of hysterosoma from sejugal furrow to apices of lamellar lobar processes 313– 329. Prodorsal shield: shape and surface as in male, 156–165 in length, greatest width 147–164 ( Figure 8 View Figure 8 (a)). Vertical setae ve represented by alveoli. Setae si thin setiform, 24–26 long, separated by 67–72; setae se 120–149 long, separated by 100–111. Humeral shields with setae c2 thin setiform, 36–47 long. Setae c3 narrowly lanceolate, without subapical tooth, 19–21 in length. Hysteronotal shield: length from anterior margin to bases of setae h3 312–326, width at largest part at the level of setae d1 152–164, lateral margins sinuous, with two concavities slightly anterior to level of setae d2, DHA absent, surface without ornamentation, borders distinctly darker than remaining surface. Dorsal setae d1, d2 present, minute. Setae h1 thin piliform, 5–6 long, situated antero-mesal to bases of setae h2. Distance between bases of h1 and lateral margins of hysterosoma 11–14. Width of opisthosoma at level of setae h2 72–81. Setae ps1 positioned dorsally on opisthosomal lobes, slightly closer to bases of h3 than to h2, equidistant from outer and inner margins of lobe. Distance from bases of setae h3 to membranous apices of lobes 51– 59. Setae f2 absent. Setae h2 256–287 long, setae h3 199–267. Supranal concavity open posteriorly into terminal cleft. Length of terminal cleft including supranal concavity 140– 148, width of cleft at level of setae h3 14–21. Interlobar membrane narrow. External copulatory tube short finger-shaped, situated on free margin of interlobar membrane, 18–26 long. Primary spermaduct guide very short, not reaching the level of setae h1. Spermatheca as in Figure 8 View Figure 8 (c), secondary spermaducts about 25 long. Distance between levels of dorsal setae and setal pairs: c2:d2 81–84, d1:d2 46 –59, d2:e2 97–108, e1: e2 41–47, e2:h2 67–74, h2:h2 56–69, h3:h3 52–573.

Epimerites I free. Epigynum 50–60 in length, 99–111 in width ( Figure 8 View Figure 8 (b)). Epimerites IVa present, thin. Adanal sclerites absent. Setae ps3 situated at posterior level of anal opening. Setae sR of trochanters III lanceolate, with acute apex, 13–17 long. Legs IV with ambulacral disc extending to level of setae h3. Length of solenidia: σ of genu I 38–44, σ of genu II 10–12, σ of genu III 16–21, φ of tibia I 59–72, φ of tibia II 68–81, φ of tibia III 55–60, φ of tibia IV 19–33, ω1 of tarsus I 16–21, ω3 of tarsus I 27–37, ω1 of tarsus II 18–23.

Differential diagnosis

The new species, Trouessartia cacica sp. nov., belongs to the capensis group ( Mironov and Chandler 2020) and is similar to T. mangaratibensis Berla, 1959 described from Psarocolius decumanus (Pallas, 1769) (Icteridae) in having, in males, setae g p iliform, postgenital plaque present, and terminal lamellae rounded, and in females, setae h1 piliform, and copulatory tube present. The new species differs from the latter in having in both sexes darkly sclerotised margins of the hysteronotal shield. In males of T. cacica sp. nov. the prohysteronotal shield is relatively longer (length × width about 1.5), and in females, the external copulatory tube is remarkably shorter, not reaching the level of setae ps1, and a few elongate lacunae are present on the hysteronotal shield posterior to setae e2. Both sexes of T. mangaratibensis have no noticeable sclerotisation on the anterior and lateral margins of the hysteronotal shield anterior to the level of setae d2; in males, the length × width ratio of prohysteronotal shield is about 1.2, and in females, the copulatory tube reaches the level of setae ps1, and the central area of hyteronotal shield around setae e2 is smooth.


The type specimens of the feather mites described by H.F. Berla – 43 species, including T. mangaratibensis (see Pacheco and Parrini 1999; Valim and Hernandes 2006), and also non-type material of A. gracilis ( Trouessart, 1885) , redescribed by Berla (1959) – were kept in the National Museum of Rio de Janeiro, and were destroyed in the fire of 2018.


The new species name derives from the generic name of the type host, Cacicus , and is an adjective.


Departamento de Geologia, Universidad de Chile


Royal British Columbia Museum - Herbarium

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