Embryonic development of human lice: rearing conditions and susceptibility to spinosad.
The embryonic development of human lice was evaluated according to the changes in the morphology of the embryo observed through the transparent chorion. Based on ocular and appendage development, three stages of embryogenesis were established: early, medium, and late. Influence of temperature and relative humidity (RH) on the laboratory rearing of Pediculus humanus capitis eggs was assessed. The optimal ranges for temperature and RH were 27-31 degrees C and 45-75%. The susceptibility of head [corrected] louse eggs to insecticide spinosad (a macrocyclic lactone) was assessed by immersion method. The results showed similar susceptibility to spinosad in early, medium, and late stages of head lice eggs. In addition, this study showed similar susceptibility of head and body lice eggs to spinosad, an insecticide that has not been used as pediculicide in Argentina (lethal concentration 50: 0.01%).
Cueto
Gastón Mougabure
GM
Centro de Investigaciones de Plagas e Insecticidas, Buenos Aires, Argentina. gmougabure@citefa.gov
Zerba
Eduardo
E
Picollo
María Inés
MI
D000818:Animals; D004338:Drug Combinations; D006801:Humans; D007306:Insecticides / Q000494:pharmacology; D018942:Macrolides / Q000494:pharmacology; D010063:Ovum / Q000187:drug effects; D010374:Pediculus / Q000187:drug effects* / Q000196:embryology*; D013696:Temperature
D004338:Drug Combinations; D007306:Insecticides; D018942:Macrolides; C415329:spinosad