Plexippoides regius

Plexippoides regius was first described in 1981 by Wanda Wesołowska.[1] It is one of over 500 species identified by the Polish arachnologist.[2] She initially described it as a nomen nudum, placed in the genus Plexippoides.[3] The genus was first proposed by Jerzy Prószyński in 1977, but was not fully described until 1984.[4] The genus name is derived from Plexippus, first raised by Carl Ludwig Koch in 1846. The word plexippus is Greek and can be translated striking or driving horses. It was the name of a number of heroes in Homer's Iliad.[5] The genus was placed in the subtribe Plexippina in the tribe Plexippini by Wayne Maddison in 2015, who listed the tribe in the clade Saltafresia.[6] It was allocated to the subclade Simonida, named in honour of the French arachnologist Eugène Simon.[7] In 2016, Prószyński combined it with 40 other genera into the group Hyllines, named after the genus Hyllus.[8] Genetic analysis has found that the species is related to those of the genera Evarcha and Telamonia.[9]

In Korea, the spider is known as the two-lined jumping spider, or Wang-eo-ri-du-jul-kkang-chung-geo-mi (Korean: 왕어 리 두줄깡충거 미).[10] Prószyński suggested that spiders identified as Helicius kimjoopili found in Korea are in fact members of this species.[11] This was confirmed and Plexippoides joopili is now a synonym for the species.[10]

Plexippoides regius is a small jumping spider. The male has a body length between 6.9 and 8.55 mm (0.272 and 0.337 in).[12] The cephalothorax measures between 3.3 and 3.91 mm (0.130 and 0.154 in) in length and typically 2.8 and 2.5 mm (0.110 and 0.098 in) in width. The elongated carapace varies between individual examples, with some being orange or yellow-brown and others dark brown. All have a very dark brown or black eye field. There are two brown bands that mark the carapace from behind the eyes to the rear. The chelicerae are reddish-brown and the remainder of the mouthparts brown. The spider has two front teeth and one back tooth. The abdomen is a yellow-brown oval, measuring between 3.59 and 4.07 mm (0.141 and 0.160 in) in length and typically 2.2 mm (0.087 in) wide. The topside is yellow and has a marking of two brown stripes stretching down from front to back and a zigzag pattern on the edges. The underside is yellowish-brown and has a dense covering of dark hairs. The legs and spinnerets are also yellowish-brown, although the legs have a dense covering of thorn-like bristles. The pedipalps are yellow with a broad cymbium that protrudes to the end of the tibial spike, or apophysis. The palpal bulb is nearly spherical and has a long centrally-located embolus that encircles it.[13][14]

The female has a body length between 7.01 and 8.65 mm (0.276 and 0.341 in).[12] The cephalothorax measures between 3.59 and 3.91 mm (0.141 and 0.154 in) in length and typically 2.93 mm (0.115 in) in width, while the abdomen is between 3.91 and 4.56 mm (0.154 and 0.180 in) in length and typically 2.57 mm (0.101 in) in width.[13][14] The body shape and markings are similar to the male. The orange carapace has two light brown stripes similar to the male and the abdomen has a similar pattern, although lighter. The legs and spinnerets are similarly yellowish-brown. The chelicerae are orange and the clypeus yellow.[15] It has a light yellowish-brown sternum shaped like a shield, truncated to the front.[16] The epigyne is a medium-sized oval with a depression towards the front where the copulatory openings can be found. The copulatory openings lead to very coiled seminal ducts. The spermathecae are heavily sclerotised and many-chambered.[17]

In shape, Plexippoides regius is typical of the genus, but can be distinguished by the two stripes that mark the abdomen and are recalled in the species name.[18]

Plexippoides regius is found in China, Korea and Russia.[1] The holotype was found in North Hamgyong Province in North Korea in 1970. Examples were also identified in other areas of the country, including South Hamgyong Province.[13] The spider was observed living in the cities of Chongjin in 1987 and Pyongyang in 1990, the latter near the Tomb of King Tongmyong.[19]

The first example of Plexippoides regius to be found in Russia was discovered in Primorsky Krai in 1979.[20] It was subsequently found in China. In 2002, specimens were collected in Henan, being discovered in Baligou, Huaiheyuan National Forest Park and the regions around Mount Song. In 2006, further discoveries were made, including in the rural areas of Tongbai. It has also been found in Dengfeng, Huixian, Xinyang, Linzhou, Luanchuan, Lushi, Neixiang, Songxian Jiyuan and Yiyang. [21] Outside Henan, the spider has been spotted in Beijing and the Chinese provinces of Anhui, Hebei, Hubei, Jilin, Shanxi, Sichuan and Zhejiang.[12]

The spider lives in mountain and field grassland. It thrives both in trees and on blades of grass.[18] The spider can be particularly found around shrubs and bushes.[16]