Scymnus (Scymnus) arciformis Chen, Wang, and Ren (Coleoptera: Coccinellidae), a New Record for India

Abstract

The genus Scymnus Kugelann, 1794 belongs to the tribe Scymnini in the subfamily Coccinellinae and is distributed worldwide (Che et al. 2021; Ślipiński 2007). More than 800 species of this genus are known to date (Gordon 2000; Kovář 2007; Pang and Yu 1993; Pang et al. 2004; Poorani 2002; Ślipiński 2007). This genus is divided into eight subgenera of which four are reported from India, Neopullus Sasaji, 1971, Orthoscymnus Canepari, 1997, Pullus Mulsant, 1846, and Scymnus Kugelann, 1794 (Chen et al. 2013; Poorani 2002). Many species of this genus, including economically important species, are unknown due to poor sampling and documentation, and as a result, only eight species have been reported from India (Poorani 2002; Poorani and Thangjam 2019). Chen et al. (2013) revised the subgenus Scymnus from China and described 27 new species, including Scymnus (Scymnus) arciformis Chen, Wang, and Ren, 2013 from Yunnan and Hainan. The aim of this paper is to report S. arciformis for the first time from India, from a mango (Mangifera indica L.; Anacardiaceae) tree in Jharkhand heavily infested with leafhoppers (Hemiptera: Cicadellidae). With this addition, the number of species of S. (Scymnus) in the Indian fauna has increased to nine. The paper with the original description (Chen et al. 2013) lacks detailed description and illustrations of head appendages, terminal ventrites, and female genitalia. Here we include illustrations and descriptions of these structures, providing measurements and ratios to allow for more precise identification as well as differentiation of the sexes of this species. The antenna and mouthparts were dissected, dehydrated with ethanol, then preserved in a cavity slide with glycerol. For genitalia dissection, the specimens were relaxed overnight, and the abdomen was removed and kept in 10% KOH for 30 minutes. The genitalia and terminal abdominal segments were dissected, rinsed with water, dehydrated in ethanol, then preserved in genitalia vials after imaging. General morphological characters were studied using a Leica stereo zoom microscope M205C and M205FA and imaging was done using a Leica MC190HD and Leica EC4 digital camera. The maps were constructed using Google Maps. Morphological terminology used mainly follows Chen et al. (2013) and Ślipiński (2007). Adobe Photoshop 7 software was used for processing the images. Voucher specimens were deposited in the National Pusa Collection (NPC), Division of Entomology, ICAR-IARI Research Institute, New Delhi, India.