Arbanitis melancholicus (Trapdoor Spider)
Workbook
13 July 2020 Male spider found wandering on wall beneath bedroom window. Ran to ground when we tried to capture him.
Several photographs taken of living spider. Lacks first pair of legs, but is otherwise intact.
Diagnostic features of family Idiopidae include:
front row of eyes curved downwards and eye field is wider than long (Fig. 4)
spinnerets are short, projecting only to the end of the abdomen
caput is covered in fine, golden hairs (Fig. 4)
Diagnostic features of genus Arbanitis include (Rix et al, 2017):
eye group is rectangular, with curved anterior row (Fig. 4)
many fine golden hairs on carapace (Figs 1-4)
two processes - RTA and dRTA - on male pedipalps (Fig 6)
tip of embolus is not bifurcate (Fig. 8)
Identified as Arbanitis melancholicus with reference to Wishart (2006).
Diagnostic features:
Large brown spider - capace length 6mm
Embolic apophysis present (arrow Fig. 9)
Embolus without prominent ridge, embolic flange with ~6 folds (Figs. 8, 9)
Embolus tip with bend (Fig. 9)
Cymbium with dorsal spines, not bristles (Figs. 6, 7)
Embolic apophysis placed about midway (Fig. 9)
Retrolateral tibial apophysis (RTA) of palp is pointed (Fig. 7)
Spinules on RTA (Fig. 7)
Large, hooked distal RTA (Fig. 7)
Male venter with dark scattered spots (Fig. 10)
Frozen on 14 July and stored in absolute ethanol #130720b.
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