Myriochila (Monelica),

Serrano, Artur R. M., 2013, Myriochila (Monelica) Confluentesubtilis (W. Horn, 1914) (Coleoptera: Carabidae: Cicindelinae): Elevation To Species Status And New Record For Guinea-Bissau, The Coleopterists Bulletin 67 (3), pp. 318-320 : 318-319

MYRIOCHILA (MONELICA) CONFLUENTESUBTILIS (W. HORN, 1914) ( COLEOPTERA : CARABIDAE : CICINDELINAE ): ELEVATION TO SPECIES STATUS AND NEW RECORD FOR GUINEA – BISSAU

ARTUR R. M. SERRANO Centro de Biologia Ambiental/Departamento de Biologia Animal, Faculdade de Ciências da Universidade de Lisboa, R. Ernesto de Vasconcelos, C2 PT-1749-016 Lisboa, PORTUGAL [e-mail]

The tiger beetle fauna of Guinea-Bissau, taking into account the relatively minor surface area of the country (37,000 km 2), is particularly rich with 37 species ( Serrano 2012), i.e. ≈1 species/ 1,000 km 2. Despite the fact that most tiger beetle species of Guinea-Bissau are more or less widely distributed throughout Africa from the Sahara to South Africa, some species seem to be more restricted in their distributions (see Serrano 2007, 2011, 2012). Cylindera (Ifasina) gulbenkiana Serrano is the only endemic species in Guinea- Bissau ( Serrano 2012).

Guinea-Bissau is a small West African country dominated by plains and covered by diverse ecotypes of vegetation, such as mangrove, herbaceous savannah, shrubby savannah, open dry forest, closed dry forest, and submoist forest or moist forest (Cantanhez) among others (Porter et al. 2004). Large areas have been cleared by human activities for agriculture, charcoal works, and, during the last two decades, the cultivation of cashew trees. The fragmentation and/or destruction of forest habitats have contributed to the decline or even extinction of local populations of some tiger beetle species ( Serrano 2007, 2012).

During an entomological expedition to Guinea – Bissau in June/ July 1995, I collected 19 tiger beetle species/subspecies ( Serrano 1997). Among those taken were 17 specimens (eight ♂♂, nine ♀♀) collected near Prábis (N11°47′05.13″, W15°45′39.51″, 6 m elevation), which I assigned to Myriochila (Monelica) fastidiosa vicina (Dejean) . On the comments to this subspecies, I pointed out that the specimens from that locality were found on “milieu humides et salins” and “présentent une couleur bronze verdâtre brilliant (pareille à M. pauliani )”. Later, remarking on Myriochila (Monelica) vicina (Dejean) , Serrano (2012) pointed out that “the specimens sampled in Guinea – Bissau close to the edges of salt marshes in the “Prabis” region resemble M. vicina confluentesubtilis (W. Horn, 1914) , a form recognized by the enlarged white elytral margins” ( Fig. 1 ). In an attempt to clarify this issue, I decided to study again these specimens from Prábis and compare them with dozens of specimens of M. vicina vicina ( Fig. 2 ) that had been collected in Guinea – Bissau ( Serrano 1997, 2007, 2012). My analysis confirmed the differences already found by Werner and Oesterele (2000) to separate M. vicina vicina from M. vicina confluentesubtilis , namely the elytral markings widened and marginally coalescent and a slightly different shape of the aedeagus ( Figs. 3, 4 ) (also figs. 7 and 9 in Werner and Oesterele 2000). The inner sac pieces for both species are similar, but slightly more sclerotized in M. confluentesubtilis . Moreover, the lateral margins of the pronotum are slightly arcuate outwards in M. vicina vicina and straight in M. vicina confluentesubtilis . Therefore, I can now categorically state that the specimens from Prábis belong to M. vicina confluentesubtilis .

This population of M. vicina confluentesubtilis is rather homogeneous, and although Werner and Oesterele (2000) maintained its subspecific status, I believe that it should be elevated to species level, Myriochila confluentesubtilis (W. Horn, 1914) , new status. The two forms were never found in the same habitat in Guinea – Bissau. While M. vicina vicina was always found in open areas of savannas and open dry forests always away from the edges of ponds or of any water courses, M. confluentesubtilis was only found close to or on the edges of salt marshes. Werner and Oesterele (2000) reported, based on Burgeon (1937), that apparently both forms could be sympatric in one locality (Sampwe, Katanga, coordinates: S9°21′15.41″, E27°26′20.27″ E, 921 m elevation) in the Democratic Republic of Congo. Myriochila confluentesubtilis was previously recorded only in this African country and its discovery in Guinea – Bissau represents a new country record, increasing the number of known species to 38 for this country. This disjunct distribution is very interesting and reflects a similar case with Myriochila peringueyi immaculipennis (W. Horn) ( Serrano 2011) . Thus while M. vicina vicina has a broad distribution, being known from most West and Central African countries (Werner and Oesterele 2000), M. confluentesubtilis is only known from Guinea – Bissau and the Democratic Republic of Congo. This disjunct distribution is probably due to the lack of surveys of the typical habitats where this species occurs, namely near the edges of salt marshes, mangroves, or even other type of swamps.

The specimens of M. confluentesubtilis from Guinea – Bissau are deposited in the Entomology Collection of the author at the Faculdade de Ciências, Universidade de Lisboa.

Figures

Figs. 1–2. Myriochila species. 1) M. confluentesubtilis, male collected near Prábis, Guinea-Bissau; 2) M. vicina vicina, male collected near Binar, Guinea-Bissau.

Figs. 3–4. Myriochila species, aedeagi, lateral view. 3) Myriochila confluentesubtilis; 4) M. vicina vicina.