Neaetha wesolowskae

Neaetha wesolowskae was first described by Barbara Patoleta & Marek Żabka in 2020.[1] It was allocated to the genus Neaetha, which itself had been first raised by Eugène Simon in 1884.The genus is named for two Greek words, néos, which means new, and théa, which can be translated as aspect.[2] The species is named for the Polish arachnologist Wanda Wesołowska.[3]

The species is hard to distinguish from others in the genus, leading to Patoleta and Żabka suggesting that understanding the relationships between the different species will require study of the genes rather than their physical attributes. [4] A DNA analysis study undertaken by Wayne Maddison and Marshall Hedin identified that the genus is most closely related to the g|enus Salticus.[5] It has also phylogenetic similarities with Carrhotus and Hasarius, amongst other genera of jumping spiders. The genus was placed in the subtribe Harmochirina in the tribe Plexippini by Maddison in 2015.[6] These were allocated to the clade Saltafresia.[7] The subtribe is divided into harmochirines and pellenines, and the genus is allocated to the latter group, which is characterised by living on the open sunny ground.[8]

The spider is small. The male has a brown carapace that is 1.49 mm (0.059 in) long and 1.3 mm (0.051 in) wide, robust, and with a distinctive sloping thorax. The abdomen is 1.2 mm (0.047 in) long and 0.71 mm (0.028 in) wide and has a pattern of three wide brown stripes. The clypeus and legs are brown. The chelicerae are brown, with two forward teeth and one rear tooth. The spinnerets are light brown. The palpal bulb has an ovoid tegulum and an embolus that is crescent-shaped. The shape of the embolus differentiates the species from the related Neaetha absheronica, Neaetha membrosa , and Neaetha tomkovichi.[3]

The female has a similar carapace, although smaller at 0.86 mm (0.034 in) long and 0.74 mm (0.029 in) wide. The legs are slightly lighter than the male and the bristles on the clypeus are longer, but otherwise the female is similar to the male. Only the abdomen differs, as it is both smaller, measuring 0.97 mm (0.038 in) in length and between 0.72 mm (0.028 in) in width, and has a pattern of darker spots on a yellow background. The epigyne is large with a central pocket. The copulatory ducts are short and the spermathecae are sclerotized.[9] The females of the genus are generally hard to distinguish.[10] This species has distinctive ovoid, rather than crescent-shaped copulatory openings. Particularly, the spider is very similar to Neaetha tomkovichi, differing in the having a larger pocket on the epigyne and the way that the spermathecae are separated rather than together.[3]

The species is endemic to Thailand.[1] The male holotype of the species was found in the Kanchanaburi province in 1979. The female paratype was found in Chonburi province during the same year. This is the most easterly that the genus has been observed. The species lives in rainforests.[4]