Vehilius jabre, Souza & Medeiros & Dolibaina & Kerpel, 2023

Souza, Janiely Alves De, Medeiros, Adalberto Dantas De, Dolibaina, Diego Rodrigo & Kerpel, Solange Maria, 2023, A new species of Vehilius Godman, 1900 (Lepidoptera, Hesperiidae, Hesperiinae) endemic to the Caatinga, northeastern Brazil: taxonomy, biology and behavior, Zootaxa 5360 (2), pp. 239-254 : 251-252

The immatures of Vehilius jabre sp. nov.

The larvae of most hesperiid species show little morphological variation between instars, and differentiation between them is usually done by measuring the width of the head capsule ( Bächtold et al. 2012; Silva et al. 2021). However, in addition to the width of the head capsule, the larvae of V. jabre sp. nov. exhibited morphological variation between instars. For example, in the first two instars, the head is black, becoming light with brown or black stripes from the third instar. The black head in the early instars is also present in Vehilius vetula (Mabille, 1878) and V. stictomenes ( Janzen & Hallwachs 2009; Cock 2012). The larvae of V. jabre sp. nov. go through five instars, as observed in V. vetula and V. stictomenes ( Janzen & Hallwachs 2009) . However, the difficulties to acquire data on the immature stages relative to other sources of information (i.e., adult morphology, molecular data) represents one of the biggest gaps in the knowledge of skippers, which in turn prevents its use in the systematic study of the group. Thus, more studies on this subject will allow the use of immature morphology, biology, and behavior integrated with traditional adult morphology and molecular data in order to generate stronger systematic hypotheses for the group.

The construction of shelters by hesperiid larvae has been frequently studied ( Weiss et al. 2003; Greeney 2003; Greeney 2009; Greeney & Warren 2011; Baer & Marquis 2021) and may be associated with the protection of immatures against natural enemies and an increase in their survival ( Lind et al. 2001; Weiss 2003, 2006; Mega & Araújo 2008). During larval ontogeny, V. jabre sp. nov. constructs only one type of shelter in the third, fourth, and fifth instar: type 1 no-cut shelter ( Greeney 2009). This type of shelter is built by folding an entire leaf in half along the midvein, and it is also found in V. stictomenes ( Janzen & Hallwachs 2009) and other Hesperiini , such as Cymaenes alumna (A. Butler, 1877) , Cymaenes tripunctus (Herrich-Schäffer, 1865) , Tigasis sp. , and Vettius phyllus (Cramer, 1777) ( Janzen & Hallwachs 2009; Cock 2009, 2012). The presence of this type of shelter in different groups of Moncina suggests a phylogenetic signal, which could be used in future evolutionary reconstructions after more immature data are gathered.

The larvae of V. jabre sp. nov. eject their faeces from the shelter. This behavior has also been recorded in at least 17 families of Lepidoptera , including Hesperiidae ( Weiss 2006) . According to several authors, faecal ejection constitutes a strategy to reduce exposure to pathogens and natural predators by removing olfactory clues ( Weiss et al. 2003; Weiss 2003; 2006). This behavior was not documented for Vehilius species before.

Regarding host plant use, Vehilius species are considered oligophagous, as the larvae feed on different genera and species of Poaceae . Vehilius stictomenes , Vehilius inca (Scudder, 1872) , and Vehilius vetula (Mabille, 1878) have been recorded feeding on Paspalum L., Homolepsis Turcz., and Panicum L. ( Kendall, 1976; Beccaloni et al. 2008; Janzen & Hallwachs 2009; Warren et al. 2009; Cock 2011). In the present study, the larvae of V. jabre sp. nov. were found on Panicum trichoides , and this is the first record of this host plant for the genus.

Endemism and conservation

The Caatinga is the largest area of tropical dry forest on the globe; however, half of its original coverage has been lost, and the remainder is highly fragmented and under different pressures. Currently, only 8% of the Caatinga is legally protected under Brazil’s national reserve legislation, and less than 2% is in reserves with full legal protection ( Teixeira et al. 2021). This scenario makes the rich and still largely unknown biodiversity of the Caatinga vulnerable. Regarding the Lepidoptera , the biome is home to the currently only known population for the endangered subspecies Heraclides himeros baia (Rothschild & Jordan, 1906) ( Papilionidae ) ( Kerpel et al. 2014).

Currently, there is not a list of the endemic taxa of butterflies in the Caatinga, but here we tentatively recognized five species: two riodinids, Melanis caatingensis (Nobre & Callaghan, 2014) and Sertania lambedor (P. Jauffret, J. Jauffret & Pessoa, 2008) , and three skippers, Cogia cursinoi (O. Mielke, 1979) , and Cogia eliasi (O. Mielke, 1979) in Eudaminae , and Chirgus veturius (Pl̂tz, 1884) in Pyrginae. Thus, V. jabre sp. nov. is added to this short list and represents the first member of the subfamily Hesperiinae endemic to this biome. None of the butterflies endemic to the Caatinga are included in the present Brazilian red list of endangered fauna, in part because of their wide distribution ( C. eliasi , Ch. veturius ), but mainly because the available information on their distribution is scanty. Vehilius jabre sp. nov. is expected to occur in most of the Caatinga extension, and the current few records only reflect the limited knowledge of the Lepidoptera fauna of the biome.

The description of V. jabre sp. nov. not only contributes to the knowledge of Moncina diversity but also expands the information on the identification, conservation, and preservation of hesperiid species in Northeast Brazil. Additionally, this new endemic species comes at a time when the sustainability of the Caatinga ecosystem is critically endangered ( Leal et al. 2017). Finally, it is worthy to mention that the site where the new species was first found is part of the recently created Serra de Teixeira National Park ( Brasil 2023), which will protect Pico do Jabre and its biodiversity.