Toxicological Trivia from July 24, 2014:  in Sertox  the color of a  latrodectus copy was brown. It was light brown, globular abdomen with velvety look and a typical figure in the form of red hourglass on the abdomen (see image). We found then that young pups Latrodectus mactans are orange, brown and white; acquire their characteristic black color with:a) Age; b) Each move; c) Both previous assertions are correct. 

Correct answer is c. Read more in spanish article:  "Comments on the bite of a ‘brown widow’