The forgotten tigers: the arboreal tiger beetles of Sri Lanka

Abstract

Thirty-one species of arboreal tiger beetles are known to occur in Sri Lanka of which twenty-five species are stated to be endemic. However, the group has not been studied for more than a century and the last organised records are provided by Fowler (1912) in his studies of the 'Fauna of British India including Ceylon and Burma (Coleoptera General Introduction and Cicindelidae and Paussidae)'. Due to high endemicity rates, biodiversity value and current disturbances and destruction to natural forests of the country, which are the main habitat types of the arboreal tiger beetles, it is important that this insect group be thoroughly studied. Therefore, a study was initiated on the 'Diversity, distribution and habitat types of arboreal tiger beetles (Coleoptera, Cicindelinae) of Sri Lanka', funded by the National Science Foundation of Sri Lanka. This review compiles and records previous information on the arboreal tiger beetles of Sri Lanka, which will provide a foundation for future studies and reveal gaps in the knowledge of this insect group. The review discusses: 1) taxonomy of the arboreal tiger beetles, highlighting the genera found in Sri Lanka and their affinities to arboreal tiger beetle genera elsewhere in the world; 2) previous locations and distribution of species throughout the island and districts and provinces from which species are not recorded, habitat and micro-habitat types; 3) morphological characters of genera and species and unique characters used for the separation of species, life-cycle strategies; and 4) methods employed to collect arboreal tiger beetle species and threats to the survival of this insect group.

Cicindelinae of Sri Lanka: New record of the arboreal tiger beetle Tricondyla gounellei Horn, 1900

“…Upon identifi cation the collected tiger beetles belonged to seven species in three genera; genus Derocrania (4 species), genus Neocollyris (1 species) and genus Tricondyla (2 species) identifi ed as T. granulifera and T. gounellei. According to the existing information, six of these species have been previously recorded from several locations in the country (Dangalle, 2018), except Tricondyla gounellei, hence, a new record for Sri Lanka.…”

“…Further, T. granulifera is slightly larger (Male: 24.08 ± 0.62 mm, n = 2; Female: 23.22 ± 0.76 mm, n = 2) than T. gounellei (Male: 21.16 ± 0.29 mm, n = 3; Female 20.42 ± 0.14 mm, n = 2). Identifi cation and separation of species by the authors are based on the keys and descriptions of Horn 1904, Maindron 1904, Fowler 1912and Naviaux 2002 The genus Tricondyla is represented in Sri Lanka by fi ve species, namely, Tricondyla femorata, Tricondyla tumidula, Tricondyla coriacea, Tricondyla nigripalpis and Tricondyla granulifera of which the latter three species are endemic (Dangalle, 2018). The present study adds a previously unrecorded species, Tricondyla Journal of the National Science Foundation of Sri Lanka 48 2June 2020 gounellei to the list.…”

“…Tiger beetles (Coleoptera, Cicindelinae) are an important group of predatory insects that play a major role in ecosystems, being an integral part of the food chains and bioindicators of the environment. Thirty-one species of arboreal tiger beetles are known from Sri Lanka of which twenty-fi ve species are endemic to the island (Dangalle, 2018). According to the existing records (Tennent, 1860;Horn, 1904;Fowler, 1912;Naviaux, 2002) and collections maintained in the country (National Museum of Colombo, Sri Lanka; Horticultural Crop Research and Development Institute, Gannoruwa, Sri Lanka) the arboreal tiger beetles in Sri Lanka belong to fi ve genera -Collyris (1 species), Protocollyris (1 species), Neocollyris (12 species), Derocrania (12 species) and Tricondyla (5 species).…”

Tiger beetles (Coleoptera, Cicindelidae) of Northern Mindanao region (Philippines): checklist, distributional maps, and habitats

“…In many regions of the world the highest diversity and species richness of epigeic tiger beetles are noted mostly on lowland areas that had a variety of habitats such as coastal areas, river banks, grasslands, and sand dunes attractive for tiger beetles (e.g., Pearson and Cassola 1992 ; Pearson et al 1997 ; Jaskuła 2011 , 2015 ; Dangalle et al 2014 ; Jaskuła et al 2019 ; Jaskuła and Płociennik 2020). On the other hand, in the tropical regions large number of Cicindelidae are typical arboreal taxa (e.g., Wiesner 1992 ; Pearson and Vogler 2001 ; Moravec 2007 ; Dangalle 2018 ) and large forests, especially natural ones, are characterized by high species diversity of such tiger beetles. In Northern Mindanao region, where more than 60% of its entire area is classified as forest land, 48% of all recorded Cicindelidae taxa are noted as arboreal taxa (Table 2 ).…”

Arboreal Tiger Beetles Recorded from Lowland Crop Cultivations in Sri Lanka

“…According to past literature arboreal tiger beetle species belonging to five genera are found in Sri Lanka. Of them, the three genera -Collyris, Neocollyris, Protocollyris, do not have fused elytra and are able to fly (Dangalle, 2018). However, species of the other two genera, Derocrania and Tricondyla, found in the crop cultivations have fused elytra and are unable to fly.…”