The toughest recorded spider egg case silks are woven into composites with tear-resistant architectures.
In this communication, we report important preliminary evidence for possibly the toughest egg case silk threads recorded to date spun by the hermit spider, Nephilengys cruentata (G¯=193MJm(-3)). We further elucidate that the egg case itself is woven with a specialised repeat cross-weave that when subjected to tension, drives perpendicular-to-force threads to pile. This piling of threads constrains damage to small areas and retains the architectural integrity of the surrounding egg case material. We deduce that by having ultra-tough threads coupled to a tear resistant architecture, N. cruentata is able to protect its eggs from predators with a considerable level of effectiveness.
Laboratory of Paper Coating and Converting, Centre for Functional Materials, Abo Akademi University, Porthaninkatu 3, 20500 Turku, Finland. Electronic address: parvez.alam@abo.fi.
Parvez
P
Alam
Kisumu Insect Farms, Kenya.
Danish
D
Otieno
Laboratory of Paper Coating and Converting, Centre for Functional Materials, Abo Akademi University, Porthaninkatu 3, 20500 Turku, Finland.
Matin
M
Nuhamunada
Kisumu Insect Farms, Kenya.
Roselyn
R
Anyango
Kisumu Insect Farms, Kenya.
Jared
J
Odoyo
Kisumu Insect Farms, Kenya.
John
J
Odhiambo
Kisumu Insect Farms, Kenya.
Kenneth
K
Onyango
D000818:Animals; D008855:Microscopy, Electron, Scanning; D047011:Silk / Q000737:chemistry* / Q000648:ultrastructure; D013112:Spiders / Q000254:growth & development / Q000378:metabolism*
D047011:Silk
Egg case; Hermit spider; Nephilengys cruentata; Silk; Tear resistance; Toughness