TRIBE NYGMIINI n.
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Rhypotoses Collenette

Type species: atima Collenette, Java, Sumatra.

The forewing venation of the genus, reviewed by Collenette (1953), is diagnostic, with vein R1 anastomosing with Rs opposite the branch of R5: R2- R4 branch off more distally than R1 and R5. This areole is therefore not homologous with the more typical one of other tribes such as Orgyiini where R1 is independent. A similar areole is seen in the New Guinea genera Parakanchia Bethune-Baker and Soretoneura Collenette (Mackey, 1981). They bear some resemblance to Rhypotoses also in facies and male genitalia. In the hindwing, both M1 + Rs and M3 + CuA1 are strongly stalked.

The forewing facies involves strong antemedial and postmedial fasciae consisting of black spots in the spaces, usually with paler edging on the side towards the medial. Sexual dimorphism in many species is extreme, with some females resembling Nygmia species such as poppaea and venata, and having been confused with other species such as N. guttistriga (See Nygmia poppaea Collenette comb.n, Nygmia venata Collenette comb.n, Nygmia guttistriga Walker stat. rev. & comb.n).

In the male abdomen, tymbals are present. The genitalia usually have a simple, triangular uncus, a large, rounded saccus and rounded or quadrilateral valves, the apex in the latter usually acute, and the ventral angle often with a distinct lobe. The aedeagus is simple, sometimes with weak lateral processes, and the vesica is without cornuti, but sometimes scobinate.

The female genitalia often have the ovipositor lobes rather triangular, the ring of segment 8 finely and densely setose; the ductus and bursa are small, flimsy, unsclerotised, the latter without a signum. The ductus may have some basal sclerotisation.

The biology of one of the Bornean species is noted below.

Schintlmeister (1994) removed ruptata Walker to Euproctis, but its features, along with those of adela Collenette, are typical of Rhypotoses. The genus is most diverse in Sundaland, with only ruptata extending significantly further north. Three species, nigrocrocea Walker, nigriplaga Swinhoe and biformis Holloway, are transferred from Aroa Walker. No species has been recorded east of Sundaland.

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