Malaria in man is caused by four distinct species of malarial parasites:
(i) π·ππππππ ππππ πππππ: incubation period in human is 8-17 days.
(ii) P. ππππππππππ: incubation period in human is 9-14 days.
(iii) P. ππππππππ: incubation period in human is 18-40 days.
(iv) P. πππππ: incubation period in human is 16-18 days