A New Distribution Record of Darkling Beetle (Coleoptera, Tenebrionidae, Cnodalonini) from Goa and Kerala, India

The tribe Cnodalonini Oken, 1843 (Coleoptera: Tenebrionidae: Stenochiinae) comprises a group of moderately sized to large darkling beetles distributed mainly in tropical and subtropical regions. Globally, the tribe includes more than 600 described species, most of which occur in the Oriental and Afrotropical regions (Bouchard et al., 2005).

In India, the tribe is moderately represented, with about 25–35 species reported mainly from the Western Ghats and northeastern parts of the country (Masumoto, 1993; Hegde & Vasanthakumar, 2021). Members of this tribe are characterized by an elongate body form, incrassate antennae, distinct elytral striae, and sexually dimorphic tibial modifications in some taxa.

The genus Gebienocamaria Masumoto, 1993 includes large, flattened beetles distributed in South and Southeast Asia. Gebienocamaria girardi Masumoto, 1993 was originally described from India (Tamil Nadu) and later reported from Maharashtra (Masumoto, 1993; Hegde & Vasanthakumar, 2021). The present study reports G. girardi for the first time from Goa and Kerala, based on collections in the National Zoological Collections of the Zoological Survey of India, Western Regional Centre, Pune (ZSI-WRC).

The identification of the specimen was carried out under a Leica S9i stereomicroscope with inbuilt photographic facility, following Masumoto (1993). Body measurements, including total body length and maximum body width, were taken using vernier callipers. Male genitalia were dissected following the method of Kalawate & Hillert (2021) and examined under the microscope. The images were processed and enhanced in Adobe Photoshop 2019. The identified specimens are deposited at the National Zoological Collections of the Zoological Survey of India, Western Regional Centre, Pune, Maharashtra, India (ZSI/WRC).

Systematic account

Order: Coleoptera Linnaeus, 1758
Family: Tenebrionidae Latreille, 1802
Subfamily: Stenochiinae Kirby, 1837
Tribe: Cnodalonini Oken, 1843
Genus: Gebienocamaria Masumoto, 1993

Species: Gebienocamaria girardi Masumoto, 1993

(Fig. 1)

Material examined. 01 Male, Goa, South Goa, Biodiversity Park and vicinity, Bhagwaan Mahaveer Wildlife Sanctuary and Mollem National Park; 26.ix.2024; coll. Rita Deb & Party (ZSI, WRC, Ent-1/5341); 01 Male, Kerala, Wayanad, Tholpetty Wildlife Sanctuary; 06.x.2024; coll. Md. Jafer Palot (ZSI-WRC-Ent-1/5342).

Diagnostic characters. Body length: 26-27.5mm, Body width: 9-10mm. Body elongate, moderately flattened and robust, dark bronze to blackish with a slight metallic sheen; dorsal surface finely punctate. Head slightly narrower than pronotum with small but prominent eyes; antennae moderately long, gradually incrassate distally. Pronotum sub-rectangular, slightly wider than long, with evenly distributed punctures. Elytra elongate, parallel-sided, bearing distinct longitudinal punctate striae with slightly convex intervals. Ventral surface dark, sparsely punctate; legs strong. In male specimens, the protibia bears a noticeable fringe of hairs along the apical half, which serves as a useful sexual diagnostic character.

Figure 1.  Gebienocamaria girardi Masumoto, 1993 male. A. Dorsal habitus, B. Ventral habitus, C. Head and pronotum, D. Scutellum with basal elytra, E. Aedeagus, lateral view, F. Aedeagus, dorsal view.

Male genitalia. The genitalia capsule is elongate; the median lobe is narrow and gradually tapers towards the apex. Apex pointed in dorsal view and slightly curved in lateral view, consistent with the original description of the species.

Distribution. India: Tamil Nadu, Maharashtra (Hegde & Vasanthakumar 2021), Goa and Kerala (present study).

These records extend the known distribution of the species within the Western Ghats region.

The examined specimens conform to the original description of Gebienocamaria girardi Masumoto, 1993, in overall morphology and male genital characters. The present records from Goa and Kerala extend its known distribution within the Western Ghats, highlighting its wider range and contributing to a better understanding of regional faunal diversity and biogeography.

Bouchard, P., Lawrence, J. F., Davies, A. E. and A. F. Newton 2005. Synoptic classification of the world Tenebrionidae. Annales Zoologici, 55: 499–530.

https://www.zin.ru/animalia/Coleoptera/pdf/bouchard_synoptic_classification_tenebrionidae.pdf

Hegde, V.D. and D. Vasanthakumar 2021. The tribe Cnodalonini from Maharashtra with two new records. Journal of Threatened Taxa, 13(7): 18947–18948. https://doi.org/10.11609/jott.5799.13.7.18947-18948

Kalawate, A.S. and O. Hillert 2018. A new species and new records of the genus Bolboceras Kirby, 1819 (Coleoptera: Geotrupidae: Bolboceratinae) from India. Zootaxa, 4457. 595–599.

https://doi.org/10.11646/zootaxa.4457.4.10.

Masumoto, K. 1993. Larger flattened species of camariine genera from Asia. Japanese Journal of Entomology, 61(2): 217–234.