Fusius distinctus Miller, 1957

Liu, Yingqi, Li, Hu & Cai, Wanzhi, 2023, Taxonomic revision of the African assassin bug genus Fusius (Heteroptera: Reduviidae: Peiratinae), European Journal of Taxonomy 910, pp. 25-55 : 36-42

Fusius distinctus Miller, 1957

Figs 6–9

Fusius distinctus Miller, 1957: 62 . Type locality: Belgian Congo [ DR Congo].

Fusius sylvestris Miller, 1957: 62 . Type locality: Uganda: Mpanga Forest. Syn. nov.

Fusius distinctus distinctus – Dispons 1969: 3. — Maldonado Capriles 1990: 358.

Fusius distinctus sylvestris – Dispons 1969: 4. — Maldonado Capriles 1990: 358.

Diagnosis

Body color black and red in large part; anterior lobe of pronotum entirely black, posterior lobe of pronotum red; legs blackish brown to black, except tarsi brown; most apex of clavus yellowish white; humerus on posterior lobe of pronotum distinct and plump; median pygophore process slender and tapered, apical half slightly twisted in caudal view, knife-shaped in lateral view with apex sharp; apex of right paramere with a round process; apical margin of dorsal phallothecal sclerite roundly angulated; process on lower right corner of lateral phallothecal sclerite tiny and sharp.

Material examined

Holotype

DEMOCRATIC REPUBLIC OF THE CONGO • ♂; “ Holotype; Type; E. BELG. CONGO: ix-x. 1946. T. H. E. Jackson. B.M.1946-354.; Fusius distinctus sp. n. (holotype) N.C.E. Miller det. 1956”; NHMUK 013586553 ( Fig. 6 ).

Paratypes

CAMEROON • 1 ♂; “ Paratype; FRENCH CAMEROONS: D’Ja Posten . Lat. 3.15 N. Long. 13.30. E. 15. v-1. vii. 1936. F.G. Merfield.; Brit. Mus. 1936-654.; Fusius distinctus sp. n. (paratype) N.C.E. Miller det. 1956”; NHMUK 013586554 • 1 ♀; “ Paratype; FRENCH CAMEROONS: D’Ja Posten . Lat. 3.15 N. Long. 13.30. E. 15. v-1. vii. 1936. F.G. Merfield.; Brit. Mus. 1936-654.; Fusius distinctus sp. n. (paratype) N.C.E. Miller det. 1956”; NHMUK 013586555 ( Fig. 7 ) .

Holotype of Fusius sylvestris Miller, 1957

UGANDA • ♂; “ Holotype; Type; Uganda Prot. Mpanga Forest. Toro . 4,800 ft. 13-23 nov. 1911.

S.A. Neave., 1912-193; Fusius sylvestris sp. n. (holotype) N.C.E. Miller det. 1956”; NHMUK 013586556 ( Fig. 8 ).

Additional material

DEMOCRATIC REPUBLIC OF THE CONGO • 2 ♂♂, 1 ♀; “ BELGIAN CONGO: 30 mls. N of Beni on Mambasa rd . 3,000 ft. 18-20. ix. 1959.; Cambridge E. African. Exped B.M.1960-50”; NHMUK .

Redescription

MEASUREMENTS [in mm, ♂ (n = 5), ♀ (n = 2)]. Body length 9.78–9.90 (♂), 10.69–11.71 (♀); maximum width of abdomen 3.23–3.50 (♂), 3.68–3.71 (♀); head length 1.63–1.68 (♂), 1.67–1.82 (♀); length of anteocular part 0.87–0.89 (♂), 0.80–0.97 (♀); length of postocular part 0.39–0.42 (♂), 0.42–0.45 (♀); head width 1.18–1.22 (♂), 1.28–1.32 (♀); eye width in dorsal view 0.21–0.22 (♂), 0.21–0.26 (♀); width of interocular space 0.68–0.76 (♂), 0.81–0.84 (♀); width of interocellar space 0.20–0.29 (♂), 0.27–0.28 (♀); lengths of visible labial segments I:II:III = 0.54–0.60:1.06–1.10:0.46–0.51 (♂), 0.50– 0.69:1.03–1.10:0.52–0.61 (♀); lengths of antennal segments I:II:III:IV = 0.86–0.84:1.71–1.77:?– 0.91:? (♂), 1.00–1.01:1.59–1.87:?–1.11:? (♀); length of anterior pronotal lobe 1.60–1.71 (♂), 1.97– 2.02 (♀); length of posterior pronotal lobe 0.90–1.10 (♂), 0.91–1.10 (♀); width of anterior pronotal lobe 2.30–2.51 (♂), 2.40–2.64 (♀); width of posterior pronotal lobe 2.88–3.22 (♂), 3.11–3.47 (♀); scutellum length 0.90–1.12 (♂), 0.83–1.06 (♀); maximum width of scutellum 1.23–1.29 (♂), 1.21–1.46 (♀); hemelytron length 6.99–7.41 (♂), 7.33–8.10 (♀).

COLORATION. Body color black and red in large part ( Figs 6–8 ); head black with labium brown; antenna blackish brown to black ( Figs 6–8 ); anterior lobe of pronotum black, posterior lobe of pronotum red ( Figs 6A , 7A , 8A ); scutellum, pleura and sterna black ( Figs 6–8 ); legs blackish brown to black, except tarsi brown ( Figs 6–8 ); base of clavus red, middle part with an oblong black spot, most apex yellowish white; corium red with a triangular black spot on area between Cu and Pcu; membrane blackish brown with a yellowish white band crossing two cells, margins of band irregular, apical part of membrane paler ( Figs 6A , 7A , 8A ); connexivum red with inner part sometimes reddish brown ( Figs 6–8 ); abdominal sternites black with lateral area red ( Figs. 6B, 6C , 7B, 7C , 8B, 8C ).

STRUCTURE. As in generic description. Humerus on posterior lobe of pronotum distinct and plump ( Figs 6A , 7A , 8A ).

MALE GENITALIA. Median pygophore process slender and tapered, apical half slightly twisted in caudal view ( Fig. 9B ), knife-shaped in lateral view with apex sharp ( Fig. 9C ); left paramere ( Fig. 9D ) slightly longer than right paramere ( Fig. 9E ), apex of left paramere blunt ( Fig. 9D ), apex of right paramere with a round process ( Fig. 9E ); apical margin of dorsal phallothecal sclerite roundly angulated ( Fig. 9F ); process on lower right corner of lateral phallothecal sclerite tiny and sharp ( Fig. 9I ). Other structures as in generic description.

Distribution

DR Congo: Beni; Cameroon: East Province; Uganda: Mpanga Forest.

Remarks

The character Miller (1957) used to distinguish F. distinctus Miller, 1957 and F. sylvestris Miller, 1957 is “legs, abdomen ventrally, except narrowly ventro-laterally, black” in F. distinctus , or “legs, abdomen ventrally, except broadly ventro-laterally, piceous” in F. sylvestris . In Dispons’ revision (1969) of Fusius , F. sylvestris was degraded as subspecies of F. distinctus and the character he used in the key to distinguish the two subspecies is “lateral part of abdominal sternites with narrow red band, rest area black” in F. distinctus distinctus or “lateral part of abdominal sternites with broad red band, rest area dark brown” in F. distinctus sylvestris .

Firstly, “black”, “piceous” and “dark brown” are relatively similar colors, and from our observation, the main colors of the abdominal sternites of the type specimens of these two nominal species are too similar to be well distinguished ( Figs 6B , 7B , 8B ). In addition, the red area on the lateral part of the abdominal sternites of the holotype of F. distinctus is relatively narrow indeed ( Fig. 6C ), but it is broad in the paratypes of F. distinctus ( Fig. 7C ), and not significantly narrower than that in the holotype of F. sylvestris ( Fig. 8C ). So, the color pattern of the abdominal sternites is an intraspecific variation and could not be a stable diagnostic character.

The type localities of F. distinctus and F. sylvestris, DR Congo and Uganda, are two neighboring countries without obvious geographical barrier between them. Hence, as there is no distinct morphological differences and geographical isolation between the two subspecies Dispons (1969) proposed, we regard F. sylvestris Miller, 1957 as a junior subjective synonym of F. distinctus Miller, 1957 .

Figures

Fig. 6. Fusius distinctus Miller, 1957, holotype, ♂ (NHMUK 013586553), habitus. A. Dorsal view. B. Ventral view. C. Lateral view. Scale bar = 2.00 mm.

Fig. 7. Fusius distinctus Miller, 1957, paratype, ♀ (NHMUK 013586555), habitus. A. Dorsal view. B. Ventral view. C. Lateral view. Scale bar = 2.00 mm.

Fig. 8. Fusius sylvestris Miller, 1957, holotype, ♂ (NHMUK 013586556), habitus. A. Dorsal view. B. Ventral view. C. Lateral view. Scale bar = 2.00 mm.

Fig. 9. Male genitalia of Fusius distinctus Miller, 1957, non-type specimen from DR Congo (NHMUK). A–C. Pygophore. D. Left paramere. E. Right paramere. F–I. Phallus. A, G. Ventral view. B. Caudal view. C, H–I. Lateral view. D–E. Outer ventrolateral view. F. Dorsal view. Scale bar: A–E = 1.00 mm; F–I = 0.85 mm.