Theridion zonulatum

Like related species, Theridion zonulatum shows clear sexual dimorphism in size, with females being notably larger than males.^[3]

Females have a body length ranging from 3.30 to 4.01 mm, with the abdomen displaying distinctive black coloration marked by transverse white bands that create a zebra-like banding pattern both dorsally and laterally.^[3] The legs show dark annulations (ring-like markings). The cephalothorax measures approximately 1.02 mm in length and 1.04 mm in width, while the abdomen is about 2.31 mm long and 1.57 mm wide.^[3]

Males are considerably smaller, with body lengths ranging from 2.17 to 2.28 mm.^[3] They share similar coloration patterns with the females, including the characteristic transverse striping on the abdomen and annulated legs.^[4]

Theridion zonulatum constructs a distinctive and complex web structure known as a "gumfoot-sheet web," which is built across the surface of green leaves.^[3] This web represents a combination of two different theridioid web types: Type 3 (Theridion-type) and Type 4 (Coleosoma-type) webs, both of which typically lack gumfoots in other species, though T. zonulatum incorporates gumfoot elements.^[3]

The web architecture consists of three distinct layers. The upper layer forms a flat "roof" constructed from unequally spaced, parallel frame-lines that serve as supporting structures, interconnected by viscid (sticky) lines arranged in a zigzag pattern.^[3] The middle layer features an expanded, bowl-shaped sheet with a knock-down trap mechanism. The lower layer contains irregularly scattered gumfoots attached to the leaf surface.^[3]

The size and complexity of the web structure depends on the dimensions of the selected leaf, with larger leaves accommodating more supporting structures and consequently larger sheet components.^[3] The spider maintains a gumfoot-free median area along the sheet to facilitate its movement within the web.^[3]