Isoplenodia 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 : 26

Genus Isoplenodia Prout, 1932

Diagnosis (based on Sihvonen 2005). Monophyly supported by eight synapomorphies: (1) pilifer absent (unique); (2) ventrolateral sensilla on proximal part of male flagellomere in multiple rows; (3) anterior ventral lamina of metathoracic metafurca absent; (4) opening on male metathoracic dorsal sclerite absent (unique; character state ‘present’ illustrated in Sihvonen 2005, Fig. 112); (5) male hindleg tarsomeres 1–5 fused; (6) cerata fully developed; (7) mappa bare; (8) ventral margin of tegumen unmodified and straight. Based on the present study, the following additional characters may be diagnostic but require further analysis: male genitalia: sacculus of valva present as a row of short, stout setae; juxta v-shaped; aedeagus bent ventrally, with a keel-shaped extension ventrally; female genitalia: lamella antevaginalis weakly sclerotized, remainder of genitalia membranous; signum absent; corpus bursae with or without small sclerotized spines.

Description. Adult: small moths, wingspan 14–19 mm ( Figs. 1–8 ). Head smooth-scaled; male antenna fasciculate or bipectinate, female antenna fasciculate. Pilifer absent. Wings light brown, medial lines faintly expressed; forewing with one or two areoles; if two areoles, R5 from distal areole, stalked with R2–R4 ( Fig. 1 ). Opening on male metathorax dorsal sclerite absent. Male hindleg outer margin hair pencil poorly developed or absent; tarsomere segments 1–5 fused, claws absent. Female hind tibia with 2 terminal spurs. Male abdomen and genitalia ( Figs. 9–20 ): anterolateral extensions on male 2nd sternite absent. Anterior margin of male 8th sternite elongated medially or concave; cerata symmetrical or rudimentary; mappa present; membranous, posterolateral appendices absent. Socii setose. Valvae symmetrical: dorsal valvula soft, setose; ventral sacculus rudimentary, upturned, almost joined ventromedially, its margin covered with pointed setae. Juxta weakly sclerotized, narrow at base, with wing-like processes. Vinculum enlarged, dorsally narrow, v-shaped. Aedeagus curved ventrally, with keel-shaped ventral extension and long caecum; vesica without sclerotizations. Female genitalia ( Figs. 21–29 ): Lamella antevaginalis weakly sclerotized; ductus seminalis opens from ductus bursae; corpus bursae elongated sac, unsclerotized or with weak spines.

Biology and Distribution. Four species are known, one from Madagascar and three from continental Africa ( Fig. 41 ). Isoplenodia moths appear to be rare, or difficult to find, with only 52 specimens located in the collections studied. Limited available data suggest that the African species are associated with wet forest or marsh mosaic habitats. The immature stages are unknown.

Figures

FIGURE 1. Detail of forewing areoles and vein venation of Isoplenodia arrogans (Geometridae genitalia slide No. 20547, BMNH).

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.

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

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 15 – 20. Male genitalia of Isoplenodia spp. Diagnostic features indicated. 15. I. kisubiensis (holotype), genitalia. Prep. No. 1326 / Pasi Sihvonen (TMP). 16. I. kisubiensis (holotype), 8 th sternite. Prep. No. 1326 / Pasi Sihvonen (TMP). 17. I. kisubiensis (holotype), aedeagus. Prep. No. 1326 / Pasi Sihvonen (TMP). 18. I. arabukoensis (holotype), genitalia. Prep. No. 1329 / Pasi Sihvonen (TMP). 19. I. arabukoensis (holotype), 8 th sternite. Prep. No. 1329 / Pasi Sihvonen (TMP). 20. I. arabukoensis (holotype), aedeagus. Prep. No. 1329 / 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).