Spintharus, HENTZ, 1850

SPINTHARUS HENTZ, 1850 View in CoL

As other theridiids, ecribellate araneoids with three tarsal claws and few or no leg spines, lacking rebordered labium, and bearing a distinct comb of setae on the fourth tarsus that is most robust in females. Carapace and abdomen pale to bright yellow. Carapace low and nearly circular. Female abdomen variable in shape, elongated to kite-like shaped, sometimes with humps, decorated with a number of small black and four larger white dots, often surrounded by red markings in the female. Dark or white stripe typically separating the uniformly coloured venter from the ornate dorsum. Colulus small bearing two setae. Male epiandrous glands may be absent ( Agnarsson, 2004: fig. 69F). Eight eyes, with lateral eyes juxtaposed, however, eye size and placement somewhat variable. Eyes typically surrounded by black markings. Chelicerae small and slender, with a single tooth, or a tooth-like process ( Agnarsson, 2004: fig. 70E, F). Legs long and thin, with leg formula 4123 and leg IV only slightly longer than leg I. Usually four small trichobothria dorsally on tibia I, four on tibia II. Trichobothria on all metatarsi (1–2), 4–5 dorsal trichobothria on female palpal tibia. Male palp with an embolus forming a single wide spiral, a large conductor and bearing a paracymbial hood ( Fig. 4J; Agnarsson, 2004: 468). Epigynum a small pit with copulatory openings separated by more than their diameter. Spermathecae clearly visible through the cuticle. Web simple H shaped ( Fig. 1A), with sticky globules near substrate ( Eberhard et al., 2008). See Hentz (1850), Levi (1954a, 1963a) and Durán-Barrón et al. (2013) for additional descriptions and diagnoses.

Note on diagnoses: We are faced with the same problems observed by Levi (1954a, 1963a) observing high variability in habitus coloration within and across species, and relatively simple and variable genitalia ( Fig. 2I–K), that offer limited information for clear diagnoses. There is no doubt that Herbert Levi was the greatest theridiid taxonomist the field has seen, and his inability to detect geographically structured diagnostic variation within this complex is revealing. Thus, our diagnoses rely primarily on molecular data. We describe, under ‘diagnosis’ morphological traits that may be of some aid in the morphological identification of the species including female abdomen shape and colour pattern, and male papal embolus shape and angle. However, in most cases, such ‘diagnoses’ are vague at best and will probably be even less useful when more variation is revealed through further specimens and when further new species will be described.

Description of colour patterns and abbreviations: We attempt to describe female abdominal shape and colour patterns focusing on the four white blotches, four posterior-most dark spots and extent of red colour markings of the abdomen. Blotches and spots will be abbreviated as follows: anterior white blotches (AWB), posterior white blotches (PWB), dark spots (DS), anterior dark spots (ADS), posterior dark spots (PDS), red markings will be abbreviated (RM), see Figure 4K for clarification.