Thereus cacao 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 : 215-216

Thereus cacao Faynel & Fåhraeus sp. nov.

LSIDurn:lsid:zoobank.org:act: 44F527B2-7D3C-460A-85C6-134D6B0FEDBE

Figures 6, 7 , 36 , 52 , 68 , 87

Type material. Holotype male ( Fig. 6 ), FW: 17.65 mm, labelled as “ GUYANE FR. // Cacao —2 ème retenue // 9 VIII 2007 // 12h25 C. schomburgkii ” (white rectangular label, black printed); “C. FAYNEL // n° 1755” (white rectangular label, black printed); “CF-LYC-380” (orange rectangular label, black printed); “ Thereus sp. ♂ // Prep. gen. n° 620 // 3. VII. 2019 // C. FAYNEL” (white rectangular label, black printed); “CFCF032 // Thereus cacao ♂ // 27/11/2022 // Diss. Klaudia Florczyk” (green rectangular label, black printed); “ Holotype ♂ // Thereus cacao // Faynel & Fåhraeus, 2025 ” (red rectangular label, black printed). The GPS data are 04°33'36''N, 52°27'46"W. Currently in RCCF collection. The holotype will be deposited in MNHN.

Paratypes ( 2♂, 2♀). FRENCH GUIANA . 1♂, same data as holotype, Coll. C. Faynel n° 1756, gen. prep. K. Florczyk CFCF032 ( RCCF) ; 1♀, Cacao, Piste Bassin , Théodore Yatcha leg., ex-coll. Christian Castelain, CF- LYC-1062*, gen. prep. K. Florczyk CFCF033 ( RCCF, illustrated on Fig. 7 ) . ECUADOR. Sucumbios. 1♀, Cerro Lumbaqui Norte , 0°01'7 N, 77°19.2' W, 1.vi.2007, 900-1000m, R.C. Busby leg., RCB05125 ( RCB) . PERU. Cusco. 1♂, Rio Araza , 500-900m, xii.1994 - ii.1995, C. Tello leg., Coll. A. Moser 637 ( AMC) .

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

Diagnosis and description. Thereus cacao sp. nov. forms a clade with T. endera and T. geminus sp. nov. ( Fig. 1 ). It differs from them by: (1) dorsal blue-violet coloration on males (grey blue in T. endera and blue in T. geminus sp. nov.) with a largest extent on FW; (2) red orange scales in VHW cell CuA 1 -CuA 2 occupying all the space between the postmedian line and the distal margin with a bigger black triangular spot inside; (3) VFW postmedian line much closer to the outer margin and VHW postmedian line recognizable by its regular series of circumflex-shaped marks between M 1 and 2A; (4) 2.24% mean genetic divergence with T. endera and 2.99% with T. geminus sp. nov. ( Table 3). Male ( Fig. 6 ). FW length: 17.6 mm, n=2. Wings. DFW blue violet with reduced black apex. DHW cell Rs-M 1 almost completely covered with blue-violet scales. VFW beige-brown with the postmedian line much closer to the outer margin. Male genitalia ( Fig. 52 ). One male dissected. Similar to T. endera and T. geminus sp. nov., but with a greater distance between the dorsal support of the brush organs and the saccus in lateral view (double arrow on Fig. 52 ); saccus wider in ventral view; 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 concave. Female ( Fig. 7 ). FW length: 17.9 mm, n=1. Wings. Similar to T. endera and T. geminus sp. nov. but with reduced VHW red cubital spot and bigger black triangular spot inside. Female genitalia ( Fig. 68 ). One female dissected. Ductus bursae longer to T. endera , shorter to T. geminus sp. nov., ostium bursae not regularly shrinking like in the other two species. 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 same type locality, similar ventral wing patterns, the same COI sequence and hence the same BIN (AEF5159).

Ethology. Both males collected in French Guiana were found feeding on Cordia schomburgkii A. DC. ( Boraginaceae ) during sunny hours, a catch at 12:25 pm, another at 12:35 pm.

Sympatry. Thereus cacao sp. nov. occurs in sympatry with T. endera in Cusco, Peru, and in allopatry with T. geminus sp. nov. ( Fig. 87 ).

Known distribution ( Fig. 87 ). French Guiana. Ecuador (SU). Peru (CUS).

Etymology. Cacao is a village in French Guiana where the inhabitants, mostly Hmong people arrived from Laos in 1977 and live mainly from agricultural practices. Specimens of Thereus cacao sp. nov. were found on the way to the basin, a reservoir that supplies the village with drinking water and it is surrounded by well-preserved forest. It is a non-Latin noun, in apposition.

Remarks. One male from Peru, Cusco (not yet barcoded), appears to belong to this species according to wing pattern. It was stored separately from T. endera in AMC.

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 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.