Thereus antecum Faynel & Fåhraeus, 2025

Faynel, Christophe, Huertas, Blanca, Crom, Jean-François Le, O’Brien, Richard & Fåhraeus, Christer, 2025, Diagnostic male secondary sexual structures and wing patterns in the Thereus genena species group (Lepidoptera: Lycaenidae: Theclinae) with the description of nine new species from Colombia, Peru, Brazil and French Guiana, Zootaxa 5728 (2), pp. 201-246 : 216-217

Thereus antecum Faynel & Fåhraeus sp. nov.

LSIDurn:lsid:zoobank.org:act: 4E97C256-50F2-4DBC-81CD-5DC66A76123F

Figures 8, 9 , 37 , 53 , 69 , 83 , 89

Type material. Holotype male ( Fig. 8 ), FW 17.15 mm, labelled as “ Guyane Française // 11. VII. 2008 // Roura // Cacao // Piste de la source // E. Amar Leg ” (white rectangular label, black printed); “Coll. DIRINGER” (white rectangular label, black handwritten); “CF-LYC-2165” (orange rectangular label, black printed); “CFCF155 // Thereus antecum ♂ // 23/04/2024 // Diss. Klaudia Florczyk” (green rectangular label, black printed); “ Holotype ♂ // Thereus antecum // Faynel & Fåhraeus, 2025 ” (red rectangular label, black printed). The GPS data of the type locality are 04°33'36'' N, 52°27'46" W. Currently in RCCF, will be deposited in MNHN.

Paratypes ( 4♂, 3♀). FRENCH GUIANA . 1♂, Cacao , Prise d’eau sur Cordia , 4.5543, -52.4634, 5.xii.2020, L616, CF-LYC-1428*, coll. Nino Page & Maeva Leroy ; 1♂, Roura , Camp Patawa, jardin, light trap, 4.5443, -52.1527, 05.vi.2021, L769, NPML_lyc38, coll. Nino Page & Maeva Leroy ; 1♂, Cacao , sentier de la source, 04°33'36''N, 52°27'46"W, 6.viii.2015, coll. Louis Diringer ; 1♂, Route de Kaw , PK 16, 261m, 04°37'38''N, 52°17'30"W, 21.vii.2011, coll. Louis Diringer ; 1♀, Route de Kaw , PK 6 sur C. schomburgkii , 29.i.2006, S. Brûlé leg., Coll. C. Faynel n° 1702, CF-LYC-429*, gen. prep. K. Florczyk CFCF034 ( RCCF, illustrated on Fig. 9 ) ; 1♀, Antecum Pata , 20.ii.2009, light trap, Poirier et Dalens leg., Coll. C. Faynel n° 1848, CF-LYC-449* ( RCCF); 1♀, Galion , 12.vii.1995, J.Y. Gallard leg., Ex. coll. Gallard N ° 137♀, gen. prep. C. Faynel 034, RCCFXPL5A07* ( RCCF) .

They have now the following labels “ Paratype ♂ [or ♀] // Thereus antecum // Faynel & Fåhraeus, 2025 ” (blue rectangular label, black printed) .

Diagnosis and description. Thereus antecum sp. nov. is the largest species of the group, sister to T. borbaensis sp. nov. in the phylogenetic tree ( Fig. 1 ), from which it is distinguished by the absence of a DFW scent patch. T. antecum sp. nov. is close ventrally to T. endera , T. geminus sp. nov. and T. cacao sp. nov. with the following differences: (1) male DFW androconia slightly pointed basally with a black halo distally ( Fig. 37 ); (2) male DHW cell Rs-M 1 completely covered by blue; (3) female dorsal coloration more grey blue; (4) only few red scales present on VHW, between cubital spot and anal spot; (5) valvae tips pointed, not rounded like the others; (5) huge mean genetic divergence: 6.56 % with T. endera , 6.83 % with T. geminus sp. nov. and 5.21 % with T. cacao sp. nov. ( Table 3). Male ( Fig. 8 ). FW length: 17.7 mm, n=2. Wings. DFW shiny metallic blue covering half the wing, oval brown scent pad, with a black halo distally. DHW blue scales covering space between veins Rs and 2A. VHW with only a few orange scales in CuA 2 -2A not connecting the anal and the cubital red spots. Male genitalia ( Fig. 53 ). One male dissected. Characterized by a large tegumen in lateral view; dorsal processes supporting the dorsal pair of brush organs not perpendicular to the tegumen edge but turned dorsally; valvae with very sharp posterior ends; saccus narrow and pointed; penis not straight with coecum forming an arch of approximately 150° relative to the axis of the penis. Eighth tergite subrectangular, anterior border convex, posterior one almost straight. Female ( Fig. 9 ). FW length: 19.9 mm, n =3. Wings. dull grey blue dorsally, beige-brown ventrally but lighter than male, same ventral wing pattern. Female genitalia ( Fig. 69 ). One female dissected. Short ductus bursae but wide in ventral view. No signum observed in the corpus bursae, and no sclerotized element in between the papillae anales. Eighth tergite subrectangular, anterior border convex, posterior one concave. The association of the sexes was based on similar type locality, similar ventral wing patterns, the same COI sequence and hence the same BIN (ACK2035).

Ethology. According to label data, males and females feed on Cordia schomburgkii A. DC. ( Boraginaceae ). A male was caught at 9:30am and another at 11:00am ( Fig. 83 ). A male and a female were attracted by light trap (photo-positiveness).

Sympatry. Thereus antecum sp. nov. occurs in sympatry with T. cacao sp. nov. and T. praxioides sp. nov. in French Guiana ( Figs 86, 87 , 89 ).

Known distribution ( Fig. 89 ). French Guiana.

Etymology. Antecume-Pata is a village on the Maroni River, southwest of French Guiana, near the border with Suriname, where Wayana ethnic group is living. It was founded at the initiative of André Cognat (1938- 2021). Antecume was his Wayana adopted name. One of the female paratype of the new species has been found by members of the French Guiana Entomological Society during a light trap organized near this village. It is a noun in apposition, not latinized.

Remarks. This species was wrongly identified as T. genena ( Faynel 2010) .

Figures

FIGURE 1. Thereus genena species group, phylogenetic tree generated with IQ-Tree using 83 COI sequences. Each specimen has the following information (if available): scientific name, process ID, country, department. Type material in red. Method of construction of the tree: Maximum-Likelihood.

FIGURES 2–17. Adults of Thereus. 2. ♂ Thereus endera (ST, Brazil, NHMUK). 3. ♀ Thereus endera (ST, Thecla thestia, Brazil, NHMUK). 4. ♂ T. geminus sp. nov. (HT, Peru, NHMUK). 5. ♀ T. geminus sp. nov. (PT, Peru, RCCF). 6. ♂ T. cacao sp. nov. (HT, French Guiana, MNHN). 7. ♀ T. cacao sp. nov. (PT, French Guiana, RCCF). 8. ♂ T. antecum sp. nov. (HT, French Guiana, MNHN). 9. ♀ T. antecum sp. nov. (PT, French Guiana, RCCF). 10. ♂ Thereus genena (ST, Brazil, NHMUK). 11. ♀ Thereus genena (Brazil, NHMUK). 12. ♂ Thereus angulus stat. rev. (HT, Colombia, ICN-MHN). 13. ♂ Thereus angulus stat. rev. (Peru, RCCF). 14. ♂ T. borbaensis sp. nov. (HT, Brazil, SMF). 15. ♂ T. ramirezi sp. nov. (HT, Peru, NHMUK). 16. ♂ T. chontachaca sp. nov. (HT, Peru, MUSM). 17. ♀ T. chontachaca sp. nov. (PT, Peru, RCCF).

FIGURES 34–49. Male forewing androconia. 34. ♂ Thereus endera. 35. ♂ T. geminus sp. nov. 36. ♂ T. cacao sp. nov. 37. ♂ T. antecum sp. nov. 38. ♂ Thereus genena. ♂ 39. ♂ Thereus tiasa. 40. ♂ Thereus angulus stat. rev. 41. ♂ T. borbaensis sp. nov. 42. ♂ T. chontachaca sp. nov. 43. ♂ T. ramirezi sp. nov. 44. Thereus ortaloides stat. rev. 45. ♂ T. confusus sp. nov. 46. ♂ T. praxioides sp. nov. 47. ♂ Thereus praxis. 48. ♂ Thereus ortalus. 49. ♂ T. aguacatal sp. nov. Wings not at same scale for comparison purpose.

FIGURES 50–59. Male genitalia. From left to right: left lateral view with penis in place, left lateral view with penis and brush organs removed (at least one), ventral view and penis in lateral view above. Black arrows show diagnostic characters (see in the text). 50. Thereus endera. 51. Thereus geminus sp. nov. 52. Thereus cacao sp. nov. 53. Thereus antecum sp. nov. 54. Thereus genena. 55. Thereus tiasa. 56. Thereus angulus stat. rev. 57. Thereus borbaensis sp. nov. 58. Thereus chontachaca sp. nov. 59. Thereus ramirezi sp. nov. Scale bars: 1 mm.

FIGURES 66–77. Female genitalia. Left lateral view (at left), ventral view. 66. Thereus endera. 67. Thereus geminus sp. nov. 68. Thereus cacao sp. nov. 69. Thereus antecum sp. nov. 70. Thereus genena. 71. Thereus tiasa. 72. Thereus chontachaca sp. nov. 73. Thereus ortaloides stat. rev. 74. Thereus confusus sp. nov. 75. Thereus praxioides sp. nov. 76. Thereus praxis. 77. Thereus ortalus. Scale bar: 1 mm.

FIGURES 81–85. Thereus species of the genena group and other similar Lycaenidae species that could be confused with in the field. 81. Thereus praxioides sp. nov., male, French Guiana (picture courtesy of Pascal Bonin). 82. Thereus near endera, in copula, Bolivia (picture courtesy of Gottfried Siebel). 83. Thereus antecum sp. nov., female feeding on Cordia schomburgkii, French Guiana (picture courtesy of Alexandre Vinot). 84. Rekoa stagira (Hewitson), female, French Guiana (picture courtesy of Stéphane Brûlé). 85. Strephonota cyllarissus (Herbst), female, French Guiana (picture courtesy of Jean-Yves Gallard).

FIGURES 88–89. Geographic distribution of the species of Thereus belonging to the genena group (question mark for imprecise data placed in the center of the province/state). 88. T. aguacatal sp. nov., T. borbaensis sp. nov., T. chontachaca sp. nov., T. ramirezi sp. nov. 89. T. antecum sp. nov., T. genena, T. tiasa.

FIGURES 86–87. Geographic distribution of the species of Thereus belonging to the genena group (question mark for imprecise data placed in the center of the province/state, circle for mounted specimen data, square for iNaturalist data). 86. T. ortalus, T. ortaloides stat. rev. (), T. confusus sp. nov., T. praxis, T. praxioides sp. nov. 87. T. endera, T. angulus stat. rev., T. cacao sp. nov., T. geminus sp. nov.