Lice in Howler Monkeys and the Ancient Americas

Sucking lice are highly host-specific ectoparasites, particularly on primates with most lice species occurring only on a single species of host. Lice are found on prosimians, New World monkeys, Old World monkeys, and apes. The genus Pediculus is found naturally on humans (Homo sapiens), bonobos and chimpanzees (Pan), howler monkeys (Alouatta), spider monkeys (Ateles), and capuchin monkeys (Cebus). This chapter concentrates mainly on the presence of Pediculus spp. in howler monkeys to provide information on the potential louse host switch between humans and Neotropical primates. Although studies on lice in New World monkeys are very scarce and outdated, after a thorough review we found P. mjobergi reports for three species of howlers: Alouatta caraya, Alouatta guariba, and Alouatta belzebul. Genetic and paleontological evidence suggest that an interchange of genetic material between humans and howler lice occurred during encounters for example for subsistence or pets, probably when modern humans moved out of Africa and entered the Americas, and that P. mjobergi, may be an evolutionary lineage of P. humanus. Keywords:Lice, Pediculus, Alouatta, Host-switch, Peopling of the Americas, New World primates