Enigmatic “love bites” and an indirect mating plug: revision of Thunberga Jäger, 2020 with description of new species (Araneae: Sparassidae: Heteropodinae)

Abstract

The huntsman spider genus ThunbergaJäger, 2020 is revised. Twenty-five species are described for the first time: Thunberga alienaspec. nov. (♂), T. befotakaspec. nov. (♂), T. boyanslatspec. nov. (♀), T. calaspec. nov. (♀), T. conductorspec. nov. (♂, ♀), T. darainaspec. nov. (♂, ♀), T. elongataspec. nov. (♀), T. gosuraspec. nov. (♀), T. jaerviispec. nov. (♀), T. jyotispec. nov. (♀), T. mafiraspec. nov. (♂, ♀), T. malalaspec. nov. (♂, ♀), T. mamaspec. nov. (♂, ♀), T. matomaspec. nov. (♀), T. millotispec. nov. (♂), T. paulyispec. nov. (♂, ♀), T. panusilemspec. nov. (♀), T. platnickispec. nov. (♂, ♀), T. rothorumspec. nov. (♂), T. rugosaspec. nov. (♀), T. samsagalaspec. nov. (♂), T. soruagspec. nov. (♀), T. v-insignitaspec. nov. (♀), T. wasserthalispec. nov. (♀), T. woodaespec. nov. (♂, ♀). The male of T. greta is described for the first time. One species is transferred to Thunberga: T. laterifusca (Strand, 1908) comb. nov. (from Eusparassus), it is considered a nomen dubium. The distribution range of the genus includes now Madagascar with adjacent islands and Mayotte. Photos of living spiders are shown for the first time revealing a possible new diagnostic character: a small white patch in front of the fovea. Another new diagnostic character is a distal V- to U-shaped field of bristles situated ventrally on metatarsus IV, the metatarsus III exhibits ventro-distally a short to very stout bristle embedded in a scopula. Metatarsi I and II possess only scopula without bristles distally. In the female genitalia, plugs were observed not only at the copulatory openings, but in few cases also at the unpaired anterior pocket, the first known case within the Entelegynae that structures other than the copulatory openings are plugged. Externally recognisable mating plugs to various degrees were found in twelve out of twenty-three species known from females. Sixteen of these exhibited paired scars at the dorsal prosoma. It is hypothesized that males grab the females with their chelicerae and cause small punctuations in the cuticle (so-called “love bites”). Morphological and possible behavioural characters of Thunberga species are discussed.