Isoplenodia vidalensis, Sihvonen, Pasi & Staude, Hermann S., 2010

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 : 32-33

Isoplenodia vidalensis sp. n. Sihvonen & Staude

Figs. 4, 5 , 12–14 , 24–26

Material Examined. Holotype: 3, labelled: “ HOLOTYPE / Isoplenodia vidalensis / Sihvonen & Staude [red rectangular label]; South Africa, / Kwazulu-Natal, Cape / Vidal, St. Lucia / reserve, coastal dune / forest / 20 m, 28.08 S. 32.33 E / 13-11-1999, H.S. Staude; South Africa / St Lucia Res / Cape Vidal / 32.33. 0 0 0 E 28.08. 0 0 0 S / 13.XI.1999 20 m / H.S. Staude 9438 / Hss d000.db; Genitalia prep. / No. 1233 / Pasi Sihvonen [blue rectangular label); Genitalia prep. / No. 1268 / Pasi Sihvonen [hindleg, blue rectangular label] [in TMP]”. Paratypes: 21 3 8 Ƥ: 1 3 2 Ƥ, labelled: “ PARATYPE [yellow rectangular label]; South Africa, / Kwazulu-Natal, Cape / Vidal, St. Lucia / reserve, coastal dune / forest / 20 m, 28.08 S. 32.33 E / 13-11-1999, H.S. Staude; South Africa / St Lucia Res / Cape Vidal / 32.33. 0 0 0 E 28.08. 0 0 0 S / 13.XI.1999 20 m / H.S. Staude 9438 / Hss d000.db; Genitalia prep. / No. 1232 / Pasi Sihvonen [blue rectangular label] [in HSS]”. 1 3 1 Ƥ, labelled: “ PARATYPE [yellow rectangular label]; South Africa, / Kwazulu-Natal, Kosi Bay Coastal Reserve/Manzengwenya, coastal forest/grassland/ 27.15.44S.32.46. 0 8 E / 50 m, / 18-10-1998, H.S. Staude; South Africa / Kosi Bay Coastal Res / Manzengwenya, 27.15.440S.32.46. 0 80 E / 18-X-1998, 50m, 9441 / Hss d000.db [in HSS]”. 2 Ƥ, labelled: “ PARATYPE [yellow rectangular label]; South Africa, Northern / Province, Gundani village, / Brachystegia woodland, / 840m, 22.39S. 30.34E, / 26-11-2000, H. S. Staude; South Africa / Gundani village / 30.34.000E 22.39.000S / 26 XI 2000 840m / H. S. Staude 9439 / Hss d000.db; [in HSS]”. 1 Ƥ, labelled: “ PARATYPE [yellow rectangular label]; RSA [ South Africa], Kwazulu- Natal / Kosi Bay Nature Reserve / 50m, 26.53S 32.51E / 12 x 2002, R & E Kyle; [In the private collection of H. S. Staude, Magaliesburg, South Africa]”. 3 3, labelled: “ PARATYPE [yellow rectangular label]; [ South Africa]Mutale [river][22°49´S, 30°24´E], Venda / N.Province [Limpopo] / 06/03/97 / N.J. Duke; [in TMP]”. 1 3, labelled: “ PARATYPE [yellow rectangular label]; Charters Creek [28°13´S, 32°25´E] / kz-Natal [KwaZulu-Natal] / RSA [ South Africa] / 5-6/10/97 / N.J. Duke; 2 males, labelled: ” PARATYPE [yellow rectangular label]; [ South Africa] Wylies Poort [22°55´S, 29°55´E] / Soutpansberg / N.Transvaal [Limpopo] / 24-26/1/88 / N.J. Duke; [in TMP]”. 2 3 2 Ƥ, labelled: “ PARATYPE [yellow rectangular label]; St.Lucia [28°22´S, 32°24´E] / kz-Natal[KwaZulu-Natal] / RSA [ South Africa] / 11-12/02/97 / N.J. Duke; [in TMP]”. 9 3, labelled: “ PARATYPE [yellow rectangular label]; [ South Africa] [KwaZulu-Natal] Zululand / Dukuduku forest / 32°20΄E 29°21΄S(sic) [28°21΄S] / 4& 5/2/89 / N.J. Duke; [in TMP]”. 1 3, labelled: “ PARATYPE [yellow rectangular label]; [ South Africa][KwaZulu-Natal],Mkuzi.Nat.Game Reserve [27°40´S, 32°19´E] / 23–26 IV 1982 / Scoble & Lawrenson; [in TMP]”. 1 3, labelled: “ PARATYPE [yellow rectangular label]; South Africa / Natal [KwaZulu-Natal] / St. Lucia Bay / 29°23΄S 32°25΄E (sic) / 29–30 IX 1974 [no collector cited]; [in TMP]”.

Description. Wings. Male wingspan 13–15 mm (forewing length 7–7.5 mm) (n=4); females 16–19 mm (forewing length 8–9 mm) (n=7). Females are larger and ground color is lighter. Wings rust brown, markings dark brown to black (males) or ochreous brown, markings light brown with tint of red, particularly in terminal area (females). Forewing costa rust brown; antemedial line barely visible, medial and postmedial lines clearly identifiable but weak; postmedial line with two angles; female medial area weakly tinted with red; terminal line absent; fringes slightly darker than ground colour. Only postmedial line barely visible in hindwings. Discal spots distinct, dark in forewings, weak or absent in hindwings. Wings colored below as above, but lighter, markings weaker; discal spots distinct also in hindwings. Head. Labial palpi short, upturned, light brown. Proboscis developed normally. Frons and vertex brown, smooth scaled; collar brown. Dorsal surface of antennae rust brown at base, lighter towards apex, mixed sparsely with black scales. 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, without hair pencils and spurs; 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-headed apex; these organs present in female also. Sternites 3–7 of male weakly sclerotized, unmodified; anterior margin of male sternite 8 weakly developed medially; mappa bare, round; cerata absent, only rudimentary sclerotizations present laterally; tergites 2–7 of male undifferentiated; tergite 8 weakly concave caudally. Female sclerites undifferentiated. Male genitalia. Small, fused, ovoid. Uncus absent; socii short, weakly setose; dorsal lobe of valva (valvula) soft, setose, short; ventral lobe of valva (sacculus) rudimentary, upturned, almost joined ventromedially, sacculus margin covered with stout setae; juxta rather weakly sclerotized, base very short, with long wing-like processes, apex slightly bent ventrally; vinculum enlarged, dorsally narrow, u-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 slightly longer than apophyses anteriores; region around ostium bursae weakly sclerotized; proximal part of ductus bursae sclerotized, cup-shaped; ductus seminalis membranous, opens from ductus bursae dorsally; corpus bursae elongated, unsclerotized.

Etymology. The name vidalensis is derived from the locality of the holotype, Cape Vidal.

Biology and Distribution. I. vidalensis is known from two disjunct areas in South Africa ( Fig. 41 ). The type locality, Cape Vidal, KwaZulu-Natal ( Fig. 30 ), and five other nearby localities all fall within the vegetation type CB 1 Maputaland Coastal Belt ( Mucina & Rutherford 2006). This vegetation type is a flat, frost free, coastal plain comprising a grassland/forest mosaic with interspersed marshes and lakes; annual average rainfall is 1200 mm, distributed throughout the year. The second group of Isoplenodia populations occurs in remnant riverine forest pockets situated on the northern slopes of the Soutpansberg mountain range in Limpopo Province. These frost free forest pockets are embedded within the drier savanna vegetation type SVcb21 ( Mucina & Rutherford 2006); annual rainfall is up to 900 mm per year, distributed throughout the year. The surrounding plains have an annual rainfall of 400–500 mm per year, with a distinct dry and wet season. I. vidalensis may prefer frost free wet habitats that retain some moisture throughout the year, and it is possible that these disjunct populations are connected via the adjacent wet areas in Mozambique (which have been poorly surveyed). The immature stages are unknown.

Figures

FIGURE 30. Coastal dune forest habitat of Isoplenodia vidalensis in eastern South Africa: the Greater St. Lucia Wetland Park in KwaZulu-Natal. Photo H. S. Staude.

FIGURE 41. Map of Africa and Madagascar displaying the known distribution of Isoplenodia species.

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).