Isoplenodia arrogans Prout, 1932

Sihvonen, Pasi & Staude, Hermann S., 2010, Revision of Isoplenodia Prout, 1932 with new records from continental Africa (Lepidoptera: Geometridae, Sterrhinae), Zootaxa 2453, pp. 25-41 : 28-32

Isoplenodia arrogans Prout, 1932

Figs. 2, 3 , 9–11 , 21–23

Isoplenodia arrogans, Prout, 1932 , Novitates Zoologicae 37: 237, ( Isoplenodia ). Types: 6 males, 1 female (in BMNH), North Madagascar: Diego Suarez [=Antsiranana].

Isoplenodia arrogans ab. degener Prout, 1932, Novitates Zoologicae 37: 237, ( Isoplenodia ). Types: 1 male (in BMNH), [ Madagascar]; unavailable infrasubspecific name.

Material Examined. Syntype: Ƥ, labelled: “[North Madagascar]: Diego Suarez [=Antsiranana],/ Feb.– April, 17./ (G. Melou); Geometridae / genitalia slide/ No. 22584 [in BMNH]”, examined. Syntypes: 6 males, labelled: ”[North Madagascar]: Diego Suarez [=Antsiranana],/ Feb.– April, 17./ (G. Melou) [in BMNH]”, examined. Other specimens: ɞ, labelled: ”Ambondro,/ Andray, S. Mad.[agascar], / early Oct. [19]34. / (R. Catala).; Rothschild / Bequest / B.M. 1939-1.; Geometridae / genitalia slide/ No. 20527 [genitalia, Pasi Sihvonen prep.]; Geometridae / genitalia slide/ No. 20547 [wings]; Geometridae / genitalia slide/ No. 20577 [head, thorax, Pasi Sihvonen prep.] [in BMNH]”, examined.

Description. Wings. Male wingspan 15–16 mm (forewing length 8 mm) (n=8); female 20 mm (forewing length 10 mm) (n=1). Wings rust to light brown, markings weak, dark brown; forewing costa approximately of the same color as forewing; antemedial line barely visible, more pronounced in female(s); medial and postmedial lines weak; postmedial line with two angles; female medial area weakly tinted with red-brown; terminal line present, dark; fringes concolorous with wings. Only postmedial line visible in hindwings (males) or medial and postmedial line continued in hindwings (female(s)). Discal spots distinct in both wings. Wings colored below as above, but lighter, markings weaker; discal spots weak. Head. Labial palpi short, upturned, ochreous. Proboscis developed normally. Frons and vertex ochreous, smooth scaled; collar dark brown. Antennae brown dorsally. Male antennae bipectinate; female antennae fasciculate. Thorax. Concolorous with wings; legs concolorous with wings; foreleg tibial spurs absent; midleg tibia with two terminal spurs, of unequal length; male hindleg tibia slightly enlarged, outer margin hair pencil weakly expressed; tarsomeres of male hindleg tarsus fused, pretarsus absent; female hindleg tibia with two terminal spurs. Abdomen. Concolorous with thorax and wings. Tympanal organs large, round, almost joined medially; ansa wide at base, expanding, narrowest below hammer-header apex; these organs present in female also. Sternites 3–7 of male weakly sclerotized, unmodified; anterior margin of male sternite 8 medially elongated; mappa bare, round; cerata present, symmetrical, apical brushes absent; tergites 1–7 of male undifferentiated; tergite 8 weakly narrower in posterior margin. Female sclerites undifferentiated. Male genitalia. Small, fused, ovoid. Uncus absent; socii long, setose, widest below apex; dorsal lobe of valva (valvula) soft, setose, long; ventral lobe of valva (sacculus) rudimentary, upturned, almost joined ventromedially, sacculus margin covered with soft setae; juxta rather weakly sclerotized, base long, with long wing-like processes, apex slightly bent ventrally; vinculum enlarged, dorsally wide, v-shaped. Aedeagus rather thin, bent ventrally about 90 degrees; caecum long, round; distinct, keel-shaped extension in ventral part; vesica unsclerotized. Female genitalia. Papillae anales soft, setose; apophyses posteriores and apophyses anteriores approximately of equal length; region around ostium bursae weakly sclerotized; proximal part of ductus bursae sclerotized laterally only; ductus seminalis membranous, opens from ductus bursae laterally; corpus bursae elongated, partially weakly spinose.

Biology and Distribution. Known only from Madagascar ( Prout 1932, Prout 1929 –1935, Viette 1990), in the north from Antsiranana and in the south from Ambondro. Northern specimens have been collected during February and April; the only southern specimen was taken in October. Immature stages and biology unknown.

Figures

FIGURES 2 – 8. Adults of Isoplenodia spp. Diagnostic features indicated. 2. I. arrogans Prout male, Madagascar, early October 1934 (BMNH). 3. I. arrogans Prout female (syntype), Madagascar, February – April (BMNH). Photo courtesy of the Natural History Museum, London, UK. 4. I. vidalensis male (holotype), South Africa, 13 November 1999 (TMP). 5. I. vidalensis female (paratype), South Africa, 13 November 1999 (HSS). 6. I. kisubiensis male (holotype), Uganda, 25 November 2005 (TMP). 7. I. arabukoensis male (holotype), Kenya, 21 July 2002 (TMP). 8. I. arabukoensis female (paratype), 21 July 2002 (HSS). Scale bar = 10 mm.

FIGURES 9 – 14. Male genitalia of Isoplenodia spp. Diagnostic features indicated. 9. I. arrogans Prout, genitalia. Geometridae genitalia slide No. 20527 (BMNH). 10. I. arrogans Prout, 8 th sternite. Geometridae genitalia slide No. 20527 (BMNH). 11. I. arrogans Prout, aedeagus. Geometridae genitalia slide No. 20527 (BMNH). 12. I. vidalensis (holotype), genitalia. Prep. No. 1233 / Pasi Sihvonen (TMP). 13. I. vidalensis (holotype), 8 th sternite. Prep. No. 1233 / Pasi Sihvonen (TMP). 14. I. vidalensis (holotype), aedeagus. Prep. No. 1233 / Pasi Sihvonen (TMP).

FIGURES 21 – 29. Female genitalia of Isoplenodia spp. Diagnostic features indicated. 21. I. arrogans Prout (syntype), genitalia. Geometridae genitalia slide No. 22584 (BMNH). Photo courtesy of the Natural History Museum, London, UK. 22. I. arrogans Prout (syntype), ostium bursae. Geometridae genitalia slide No. 22584 (BMNH). Photo courtesy of the Natural History Museum, London, UK. 23. I. arrogans Prout (syntype), corpus bursae. Geometridae genitalia slide No. 22584 (BMNH). Photo courtesy of the Natural History Museum, London, UK. 24. I. vidalensis (paratype), genitalia. Prep. No. 1232 / Pasi Sihvonen (HSS). 25. I. vidalensis (paratype), ostium bursae. Prep. No. 1232 / Pasi Sihvonen (HSS). 26. I. vidalensis (paratype), corpus bursae. Prep. No. 1232 / Pasi Sihvonen (HSS). 27. I. arabukoensis (paratype), genitalia. Prep. No. 1327 / Pasi Sihvonen (HSS). 28. I. arabukoensis (paratype), ostium bursae. Prep. No. 1327 / Pasi Sihvonen (HSS). 29. I. arabukoensis (paratype), corpus bursae. Prep. No. 1327 / Pasi Sihvonen (HSS).