The Seychelles Archipelago comprises 115 islands in the western Indian Ocean. Along with Madagascar, Comoros, Réunion, Mauritius and Rodrigues these islands form the Malagasy subregion, which is part of the Afrotropical biogeographical region. The Seychelles experience a tropical humid climate (Walsh 1984), and can be broadly divided into the northern granitic and southern coral islands (Braithwaite 1984) (Fig. 1). The granitic islands, along with the two coral islands of Bird and Denis, make up the inner Seychelles islands. The Lepidoptera fauna of the Seychelles can be considered fairly well-known, with much historical and recent work been done (Matyot 2005; Gerlach & Matyot 2006). This paper presents a new hawkmoth record for Seychelles. Furthermore, an updated biogeographical checklist of all known Seychelles hawkmoth species is provided.
A single specimen of the large hawkmoth Euchloron megaera megaera (Linnaeus, 1758) (Fig. 2) was collected on the 27 October 2005 adjacent to the Veuve Special Nature Reserve on the granitic Seychelles island of La Digue at La Passé (Fig. 1: inset map). The specimen was found resting on a white coloured wall at 0730 h. The specimen is housed in the private collection of the author. The Veuve Special Nature Reserve was set up in 1982 to protect the last remaining population of the Critically Endangered Seychelles Black Paradise flycatcher, Terpsiphone corvina (Newton, 1867) (Aves: Muscicapidae) (Currie 2002), locally known as ‘Veuve’. The reserve lies on the western plateau of the island and was originally covered with marshland, and extensive indigenous forests dominated by Calophyllum inophyllum L. (Calophyllaceae) and Terminalia catappa L. (Combretaceae) trees. Most of the original vegetation has been removed or degraded, with wetland drainage, agricultural and urban development being significant anthropogenic threats (Skerrett et al. 2001). Although this hawkmoth is easily identifiable it can be confused with the smaller but similar looking Basiothia medea (Fabricius, 1781).
Distribution and faunal affinities of the Seychelles hawkmoths. C = Comoros; Ma = Madagascar; R = Réunion; M = Mauritius; A = Continental Africa; SE = Seychelles Endemic; X = taxon present in geographic area; (X) = taxon present as different subspecies in geographic area. Taxon distribution based on Carcasson (1967); Lawrence (2009); Matyot (2005); Pinhey (1962).
Two other species of hawkmoths have been recorded from La Digue. These are Acherontia atropos (Linnaeus, 1758) (Fletcher 1910) and Cephonodes tamsi Griveaud, 1960 (Mazzei 2009). C. tamsi is endemic to the granitic Seychelles islands where it is Red-Listed as Critically Endangered (Gerlach & Matyot 2006).
Larvae of E. megaera are polyphagous on numerous species within the plant family Vitaceae. E. m. megaera larvae have been recorded on Cissus sp. and Vitis sp. (Kroon 1999). In Seychelles, these plant genera are represented by C. rotundifolia (Forskk.) Vahl and V. vinifera L. respectively. V. vinifera has been recorded on Mahé and Praslin, and C. rotundifolia occurs on Mahé (Friedmann 2011). However, there are no records of these plants on La Digue so far.
Euchloron megaera is widespread across the Afrotropical region where five subspecies are recognised: 1) E. m. megaera (Linnaeus, 1758) occurs throughout most of Africa south of the Sahara, including Grand Comore in the Comoros; 2) E. m. asiatica (Haxaire & Melichar, 2009) is found in Yemen; 3) E. m. lacordairei (Boisduval, 1833) occurs on Madagascar and the Comoro islands of Mayotte, Mohèli and Anjouan; 4) E. m. orhanti (Haxaire, 2010) is found on Réunion; 5) E. m. serrai (Darge, 1970) is restricted to São Tomé off the west coast of Africa.
Interestingly, the Seychelles specimen belongs to the African mainland subspecies and not the Madagascan or Réunion subspecies. Whether this moth has been previously overlooked by researchers or the species was recently introduced is unknown. It may represent a vagrant specimen or an ephemeral population. An analysis of the faunal affinities of the Seychelles butterfly fauna found that the granitic islands shared a closer affinity to continental Africa than to Madagascar or Comoros (Lawrence 2014), suggesting that natural arrival of this species in Seychelles cannot be dismissed.
This record increases the number of hawkmoth species found in Seychelles to 15. One species is represented by two subspecies making the total number of taxa 16 (Table 1), of which 31.25% are endemic (i.e. three species and two subspecies). Five taxa are widespread across the Afrotropical region including the Malagasy subregion, and three species are confined to the Malagasy subregion.
I would like to thank Dr. I. Kitching of the Natural History Museum, London for identifying the specimen and for information on the distribution of Hippotion aurora subspecies.