Phaenochitonia Stichel, 1910 (Riodinidae: Symmachiini) contains 7 species distributed on Neotropics, and they are easily confounded with species of Comphotis (Incertae Sedis section) but can be distinguished by the presence of concealed androconial scales in the abdominal tergites of the males (an exclusive character of Symmachiini) and the Sc vein not fused with R₁ (Hall & Willmott 1996; Callaghan & Lamas 2004). The females, usually with orange or red transverse bands on the fore wings or on both wings, are very different from the males which possess red markings traversing both wings or restricted to the inner margins of the hind wings (Hall & Willmott 1996).

Phaenochitonia pseudodehilis Hall & Willmott, 1996 was described based on a single male specimen from Cuiabá - River System, Mato Grosso, Brazil (Hall & Willmott 1996). Since then, the female of P. pseudodebilis has been unknown. Here we provide the first description of the female of P. pseudodehilis and an update on its geographical distribution, which until now was known only from its type locality.

Fig. 1.

Female of Phaenochitonia pseudodebilis Hall & Willmott, 1996: A, dorsal view, and B, ventral view.

Description of Phaenochitonia Pseudodebilis Female

Description (Figs. 1 and 2): Fore wing length 7 mm. Ground color of dorsal and ventral surfaces dark brown with an orange transverse band on both wings. The basal area of both wings on ventral surface with general spot pattern similar to male. Abdomen entirely brown, different from that of the male, which has a red stripe on dorsum. Female genitalia: sterigma formed by a rectangular lamella antevaginalis and an inverted U-shaped postvaginalis lamella; ductus bursae thinned, with apical third sclerotized and about three times length of bursa copulatrix; bursa copulatrix totally membranous, with a hook-shaped signum dorsally.

Remarks on the Distribution of Phaenochitonia Pseudodebilis

The only known record of P. pseudodebilis was from its type locality, Cuiabá - River System, Mato Grosso, Brazil. However, by the examination of the Riodinidae deposited in the Collection of Entomology Padre Jesus Santiago Moure, Department of Zoology of the Federal University of Paraná (DZUP), 13 specimens of P. pseudodebilis collected in the 1970s at Alto Rio Arinos, Diamantino, Mato Grosso, were identified. Later, in the 1990s, 5 males and 1 female were also observed and collected in gallery forests about 18 km from Ribeirão Cascalheira, which is 530 km northeast of Diamantino. The individuals were always associated with a gallery forest, a humid forest characteristic of the Cerrado (Brazilian savanna) vegetation.

Fig. 2.

Female genitalia of Phaenochitonia pseudodebilis Hall & Willmott, 1996: A, lateral view, and B, ventral view.

The Cerrado domain has a heterogeneous physiognomy, ranging from open areas to dense forests, and is highly threatened due the loss of many of its native areas (Myers et al. 2000). The gallery forests play an key role in the maintenance of diversity of the Lepidoptera of the Cerrado (Camargo 2001; Brown & Giffordi 2002; Scherrer et al. 2013), which underscores the importance of preserving these habitats.

The records of P. pseudodebilis are scarce, as are those of many other butterflies that occur in the Cerrado biome. Thus it is important to emphasize the need to intensify the development of well-sampled inventories of butterflies in the Cerrado domain, as well as in the transitional areas between the Cerrado and Amazonia. Probably new records of P. pseudodebilis will be revealed as new inventories are performed in this area, enabling a better assessment of its distribution and its conservation status.