Range extension of the Lilac Silverline Apharitis lilacinus to southern Rajasthan and a review of the literature

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The Lilac Silverline Apharitis lilacinus (taxonomy following Varshney & Smetacek 2015) is an exceedingly rare species of butterfly of the family Lycaenidae (also referred to as "the blues" or "gossamer-winged butterflies") that was first described in 1884 from a specimen with unknown origin (Moore 1884). Little is known of its ecology, distribution, and conservation status in India. In this note, we describe a recent observation of the species that constitutes a range extension. We also provide a thorough review of literature relating to this species with the intent to collate dispersed information to develop a better understanding of the ecological requirements of the Lilac Silverline.
On 18 February 2020, during a visit to the southern part of Kumbhalgarh Wildlife Sanctuary in southern Rajasthan, we spotted a lycaenid butterfly sunning itself perched on a rock in an area that was severely degraded by cattle grazing, with few scattered trees of Butea monosperma, Lannea coromandelica, Acacia species, and Mallottus philippensis amid sparse Lantana camara (Image 1a,b). The butterfly sighting was <50m from a dried stream bed. We uploaded images of the butterfly to the online repository iNaturalist. org as an unidentified Lycaenidae (www.inaturalist. org/observations/38831801).
Multiple reviewers identified the species as the Lilac Silverline, and we too confirmed the identification with butterfly experts and with photographs available on the world wide web. The specimen we photographed was a dry season form with a part of one wing missing possibly due to a predation attempt (Image 1a). This is the first record of this butterfly species from the Aravalli Hills and is also the first record from Rajasthan State (Sharma 2014;Jangid et al. 2016). Careful observations for this species throughout the year will help to confirm if it is resident in the area or a seasonal visitor.
Historic literature points to the Lilac Silverline always being rare in locations it has been recorded in. Early collections of butterflies include a few specimens of the Lilac Silverline 40km from Rawalpindi, Pakistan in November 1885 (described incorrectly as a new species called Azanus uranus; Butler 1886), and from Mhow in Madhya Pradesh (described as a new species called Aphnaeus aestivus; Swinhoe 1886). Very small numbers of the species have also been collected from Kasauli (Himachal Pradesh), Malda (West Bengal), Bengaluru (Karnataka) and north Lakhimpur (Uttar Pradesh) of both the wet and dry forms (Riley 1925). Observations have J TT been made of the species' habits at Chandigarh (Punjab), Hardwar (Uttaranchal), and at Palmaner in Chittoor District (Andhra Pradesh; Wynter-Blyth 1957). These early records point to the species being widespread but always sparse.
More recent observations of the Lilac Silverline have been few but significant. The species was rediscovered in Bengaluru after a century by A.R. Nitin on 23 December 2012 (de Nazareth 2013), and is now regularly photographed throughout the year, at Hessarghatta Lake with eggs and caterpillars indicating that the location has a resident breeding population of the species (Sheshadri et al. 2013;Sengupta et al. 2020). Another photographic record was obtained for the first time in northeastern India in May 2018 in Daying Ering Wildlife Sanctuary in Arunachal Pradesh (Kaman 2018). The Lilac Silverline was also photographed on 25 September 2019 from the Agastya Campus in Chittoor District, less than 60km from Hesaraghatta Lake in Bengaluru, constituting a rediscovery of the species in Andhra Pradesh (R. Bhanumati pers. comm. 2020). The Agastya Campus has been restored to a scrub-savanna mixture from fallow fields, and only one sighting of the Lilac Silverline has been made there despite multiple years of observations for butterflies (R. Bhanumati pers. comm. 2020).
Both historic and current observations match the distribution provided by Varshney & Smetacek (2015) for the Lilac Silverline: "Gujarat to Karnataka; Himachal Pradesh to Assam". Our record from Rajasthan adds to the distribution range, and to existing conclusions that the species is widespread in the Indian subcontinent September, and the species is resident in Bengaluru. Available information is therefore inadequate to comment on the seasonality of the species in other locations.
A few observations are available of the habitats required by the Lilac Silverline. Wynter-Blyth (1957) notes that the species is scarce but widespread in open plains, scrubby hills, and in gram fields. Hesaraghatta, where recent observations of the species have been made, is an urban wetland heavily disturbed by human activity (Sheshadri et al. 2013), and the recent sighting in Chittoor is from an institutional campus (R. Bhanumati pers. comm. 2020). Our observation of the Lilac Silverline was from a heavily degraded part of the Kumbhalgarh Wildlife Sanctuary (see Image 1). The observations collectively suggest that the Lilac Silverline frequents a range of habitats, perhaps most commonly using areas that experience human activity, including low levels of urbanization, cropping, and cattle grazing. The sightings at Hesaraghatta and our observation at Kumbhalgarh were made close to natural water sources suggesting that this species is often found near surface water.
It is fortunate that the Lilac Silverline is so widespread and appears to be compatible with several forms of human disturbance given the high protection status of the species (Schedule II of the Indian Wildlife Protection Act 1972; Sengupta et al. 2020). In some locations like Bengaluru, the rarity of this butterfly species has attracted photographers in large numbers whose traversing of the habitat in vehicles indiscriminately appear to be destroying its host plant species in the only site where the species is confirmed to have a breeding population (Seshadri et al. 2013). Such uncontrolled activities require to be curtailed to enable