Evaluation of four pediculicides against the head lice Pediculus h. capitis.

Four pediculicides were tested against head lice in-vitro. The LT50 for Licid ranged between 10.75 (at conc. 50%) to 25.08 (at conc. 1%). All lice died with conc. 100% within 5 minutes. With Malathion, the LT50 ranged between 4.23 to 9.3 at conc. 50% to 1% respectively. All lice died with conc. 57% within 3 minutes. With Benzanil, the LT50 ranged between 20.85 to 44.34 at conc. 50% to 1% respectively. All lice died at conc. 2.5% within 10 minutes. With Para plus, the LT50 ranged between 18.46 to 29.5 at conc. 100% to 50% respectively. All lice died with conc. 100% within 30 minutes. So, the least time needed to kill all lice was given with Malathion (3 minutes). The least dose of pediculicide needed to kill all lice was those of Benzanil (1% = 0.025) and Malathion (1% = 0.57). The whole results were discussed regarding the advantages and disadvantages of these pediculicides.