Tactusa flexus Fibiger

Fibiger, Michael, Han, Hui-Lin & Kononenko, Vladimir S., 2011, Five new species and one new subspecies of Micronoctuidae from China, with a checklist of Chinese species, including Taiwan (Lepidoptera: Noctuoidea, Micronoctuidae), Zootaxa 2777, pp. 41-53 : 45-46

Tactusa flexus Fibiger , new species

( Figs. 8 , 18 )

Type material. Holotype. Male, China, Yunnan prov., Jiangcheng, 15–17.ix.2008, leg. Han, H.L. & Liu, E., genit. prep. 6214 M. Fibiger, coll. NEFU.

Diagnosis. T. flexus is best placed in the T. artus Fibiger 2010 species-group, that comprises 10 species ( Fibiger 2010). It differs from the other species in the artus species-group by the broad valva; ampulla inwardly and outwardly almost straight, with upturned tips; the dorsal tip with short, stout spines, directed outwards; coecum very short and broad, triangular; phallus strongly coiled, curved up and down; carina with bifurcately pointed apex. It differs from other Tactusa species by the almost equally broad, prominently dorsally upturned ampulla; the medially extremely constricted juxta-anellus plate; and at ductus ejaculatorius the very broad; and prominently curved phallus.

Description. Adult ( Fig. 8 ). Wingspan: 11.5 mm, forewing narrow. Head, patagia, and base of costa black; ground colour of forewing light beige, with black costal-medial patch, and with black subterminal and terminal area, including fringe; cross-lines absent, except relatively broad white-beige subterminal line and a terminal line marked by black intervenal dots; reniform stigma almost invisible, beige, outlined by a few brown scales. Hindwing unicolourous grey, with discal spot; fringe grey. Ventral surface light brown.

Male genitalia ( Fig. 18 ). Upper part of tegumen thread-like; vinculum and saccus of triple width; saccus short, V-shaped; valvae relatively wide, asymmetrical, right valva shorter; costa inwardly with short, triangular flap; ampulla broad and wide, ventral part largest, dorsal upper part slightly upturned, with a short row of small spinelike setae; digitus small, plate-like, heavily sclerotised; juxta very short, triangular, strongly constricted medially, with semi-circular opening dorsally for position of phallus; phallus tapered from ductus ejaculatorius, strongly curved; carina pointed; vesica unarmed.

Female unknown.

Bionomics. The biotope is a moist, mainly broad-leaf forest with shrubs and herbaceous plants, close to a river. All specimens were collected at light in mid September. The early stages are unknown.

Distribution. ( Fig. 30 ) China (Yunnan prov.).

Figures

FIGURES 1 – 8. Micronoctuidae spp., adults. 1. Bellulia bibella, male, holotype, China, Yunnan (NEFU); 2. B. bibella, female, paratype, China (NEFU); 3. Mimachrostia fasciata, male, China, Yunnan (NEFU); 4. Micronoctua occi, female, China, Liaoning (NEFU); 5. Parachrostia pura, male, holotype, China, Yunnan (NEFU); 6. Parachrostia pura, male, paratype, China, Yunnan (NEFU); 7. Tactusa virga, male, holotype, China, Yunnan (NEFU); 8. Tactusa flexus, male, holotype, China, Yunnan (NEFU).

FIGURES 14 – 18. Micronoctuidae spp., male genitalia. 14. Bellulia bibella, holotype, China, Yunnan (NEFU); 15. Mimachrostia fasciata, China, Yunnan (NEFU); 16. Parachrostia pura, holotype, China, Yunnan (NEFU); 17. Tactusa virga, holotype, China, Yunnan (NEFU); 18. Tactusa flexus, holotype, China, Yunnan (NEFU).

FIGURES 26 – 30. Collecting sites and distribution map. 26. Broad-leaved and mixed forest, Huangguoshu, Prov. Guizhou. 27. Broad-leaved forest and banana plantations, Huangguoshu, Prov. Guizhou; 28. Broadleaved forest, Jiangcheng, Prov. Yunnan; 29. Mixed forest with Pinus yunnana, Lancang, Prov. Yunnan 30. Distribution map. Collecting localities: 1. Huangguoshu (Prov. Guizhou) 2. Guanling (Prov. Guizhou); 3. Lincang (Prov. Yunnan); 4. Mojiang (Prov. Yunnan); 5. Jiangcheng (Prov. Yunnan); 6. Lancang (Prov. Yunnan); 7. Jinghong (Prov. Yunnan).