<p>Development of spiderlings of <i><a href="//commons.wikimedia.org/wiki/Latrodectus_mactans" title="Latrodectus mactans">Latrodectus mactans</a></i> from Lima, Peru. Left venter, right dorsum with legs. 1:After hatching (males and females). 2: After first molt (males and females). 3: After second molt (males and females); at right, variant pattern. 4: After third molt (penultimate male) 5: After fourth molt (adult male). 6: After third molt (female). 7: After fourth molt (female). 8: After fifth molt (female). 9: After sixth molt (adult female).
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Molts are counted after leaving egg-sac; there is one molt within egg-sac. White: white; crosshatch: light brown; double crosshatch: dark brow; light stipple: orange; dark stipple: red; black:black. There may be a yellow fringe around the red in areas marked white.
Herbert W. Levi and John D. McCrone, in: Psyche 73:180-186.
CC BY 2.5
<a rel="nofollow" class="external free" href="http://psyche2.entclub.org/articles/73/73-180.pdf">http://psyche2.entclub.org/articles/73/73-180.pdf</a>