Kenny- Almost all of the adult lepidus klauberi that I have seen here in SE AZ have chestnut/yellowish colored tails, somewhat less brightly colored than the juveniles, but definitely contrasting to the dorsal body coloration. If you look at the species description given by Gloyd in 1936, you will see that he describes the subspecies of klauberi in this same manner, with regard to the tail coloration. I have no experience with lep leps, but the adults that I have seen in pictures don't seem to have this tail coloration. (maybe the NM/TX lep klaubs don't have the same tail coloration as the klaubs in AZ do? that I can't answer)
As for the question "why do lepidus stop caudal luring?", maybe the answer has to do with their strike range? Perhaps the babies are so tiny that they have difficulty getting close enough to prey to envenomate them, and once they get above a certain size they can ambush prey from a greater distance. Another thing to keep in mind is that they "switch" prey bases to some degree as they grow. AZ klauberi tend to eat Scolopendra centipedes and lizards almost exclusively, slowly switching to mammals and lizards as they grow up. Perhaps a caudal lure is more effective with the prey eaten by juvie leps in comparison to the prey eaten by adult leps. (Holycross wrote the article about lepidus diet in 2000) mostly ideas, but they seem to make a little sense to me...
