A spider is a tree with at most one branch (a vertex of degree least 3) centred the if it exists, and any otherwise. graph G arachnoid for v G, there exists spanning v—in other words: are spiders everywhere! Hypotraceable graphs non-traceable in which all vertex-deleted subgraphs traceable. Gargano et al. (2004) defined as natural generalisations traceable asked existence that (i) non-hypotrace...

The influence of web design on prey capture efficiency was investigated in the orb-webs of Octonoba sybotides under different prey conditions (abundant and limited). The insects captured by artificial traps under limited prey conditions were smaller than those captured under abundant prey conditions. O. sybotides webs with spiral stabilimenta (SP webs) have a narrower mesh and a larger catching...

In animal societies, behavioral idiosyncrasies of the individuals often guide which tasks they should perform. Such personality-specific task participation can increase individual task efficiency, thereby improving group performance. While several recent studies have documented group-level benefits of within-group behavioral (i.e., personality) diversity, how these benefits are realized at the ...

BACKGROUND Interspecific coevolution is well described, but we know significantly less about how multiple traits coevolve within a species, particularly between behavioral traits and biomechanical properties of animals' "extended phenotypes". In orb weaving spiders, coevolution of spider behavior with ecological and physical traits of their webs is expected. Darwin's bark spider (Caerostris dar...

A twig-lining population of Latouchia swinhoei Pocock, 1901 (Ctenizidae) was found in Okinawa in a habitat also densely populated by other trapdoor spiders (Ryuthela nishihirai, Mesothelae). Specimens were tested in the laboratory for their utilization of objects offered to them for attachment to the rim of the burrow. The behavioural capacity of twig-lining is discussed in comparison with othe...

TWO VENERABLE groups of spiders spin orb webs: the cnbellate Ulobondae, weavers of calamistrated sticky silk, and the ecribellate Araneidae, weavers of true viscid silk (Figs. 12.2, 12.1). "Cnbellate" spiders possess a cnbellum and a calamistrum. The cnbellum is a flat, complex spinning plate from which the cnbellate silk issues; the calamistrum is a comb of bristles on the fourth metatarsi use...