Journal of Threatened Taxa | www.threatenedtaxa.org | 26 June 2022 | 14(6): 21318–21320
ISSN 0974-7907 (Online) | ISSN 0974-7893 (Print)
#8052 | Received 19 May 2022 | Finally accepted 14 June 2022
Rediscovery of Gardena melinarthrum Dohrn from Sri Lanka
Tharindu Ranasinghe 1 & Hemant V. Ghate 2
1 Butterfly Conservation Society of Sri Lanka, 762/A, Yatihena, Malwana 11670, Sri Lanka.
2 Post Graduate Research Centre, Department of Zoology, Modern College of Arts, Science & Commerce (Autonomous), Shivajinagar, Pune, Maharashtra 411005, India.
1 email@example.com, 2 firstname.lastname@example.org (corresponding author)
The foregoing paper by Hiremath et al. (2022) points out that even though Gardena melinarthrum Dohrn, 1860 was first described on the basis of an apterous specimen collected from Sri Lanka (= Ceylon), there were no details of the location; more important fact is that there is no subsequent record of this species from Sri Lanka since 1860.
We are now confirming the presence of G. melinarthrum from Sri Lanka, after a gap of over 150 years, from three different localities shown in the map (Image 2). We are only providing photographic evidence, as the specimen collection was not permitted. All observed individuals were macropterous.
All the individuals were photographed using Canon EOS 7D or Canon EOS 7D Mark ii camera, with a Canon EF 100 mm f/2.8 L IS USM macro Lens. The map was prepared using Las Palmas version of QGIS.
All the specimens observed were about 25 mm long and showed specific proportion of the various regions of the fore leg which are diagnostic: especially important key character showed by the specimens was that the basal spineless area of the fore femur was about one-third of the total length of the femur. Wygodzinsky (1966) additionally mentioned in the key that the basal spineless area is at least 10 times in length of the first femoral spine (including its basal tubercle). These characters are evident in the close up images provided here (Image 1c).
The first observation of G. melinarthrum on 28 January 2016, was in Puleliya, Anuradhapura District of Sri Lanka. It was photographed on outside wall of a village house, at around 1910 h, most probably attracted to the electric lights on the wall. The area surrounding the house was a typical home garden with some crops and wild vegetation (Image 1a).
Another individual was photographed when it was attracted to the lights, in a guest house situated in front of a man-made lake, on 02 October 2021, in Mahaoya, Ampara District of Sri Lanka, at around 2030 h. It was actively flying towards the light (Image 1b).
Most recent sighting of this species was during a biodiversity assessment survey in Mannar District of Sri Lanka. Two individuals of G. melinarthrum were observed on 10 March 2022 in Andankulam at 1220 h. One individual was observed resting on a web of the spider Parawixia dehaani (Doleschall, 1859) and the other one was resting on a twig, few meters away, in nearby forest habitat.
Since most Emesinae tend to be nocturnal (Wygodzinsky 1966), the same can be assumed for G. melinarthrum as well, since both these observed individuals in Andankulam did not move and appeared to be resting during day time, in a shaded area. The insect was actually observed flying towards light at night on two separate occasions.
A map showing three recorded locations is presented here (Image 2). All the recorded locations are from the dry zone of Sri Lanka. Based on that, we can assume that this species mostly inhabits dry mix evergreen forests, but we can’t say with conviction that this species is restricted to the dry zone. More targeted surveys are needed to confirm its range of distribution within Sri Lanka.
It is indeed heartening that such a delicate predatory bug is still present and is quite widely distributed in Sri Lanka. We did not observe any apterous form, may be because we did not look closely at the various undisturbed places that harbor spider webs. A search for such areas will be surely fruitful. This note is a kind of rediscovery of this interesting bug.
Hiremath, S.R., S. Saikia & H.V. Ghate (2022). Authentic report of the emesine bug Gardena melinarthrum Dohrn, 1860 (Hemiptera: Heteroptera: Reduviidae) from India. Journal of Threatened Taxa 14(6): 21296–21301. https://doi.org/10.11609/jott.7902.14.6.21296-21301
Wygodzinsky, P.W. (1966). A monograph of the Emesinae (Reduviidae, Hemiptera). Bulletin of the American Museum of Natural History 133: 1–614.