The Susceptibility of Autogenous and Anautogenous Races of Culex pipiens to Infection with Avian Malaria (Plasmodium relictum)

Abstract

1. Anautogenous English and autogenous Greek, Hungarian, Maltese and cross-bred strains of C. pipiens were infected with an Algerian and a German strain of P. relictum.2. The different strains of C. pipiens behaved similarly as regards susceptibility and transmission towards the same strain of P. relictum.3. The two strains of malaria differ in the infection rate produced in mosquitoes. The Algerian strain produces an infection rate of about 89 per cent., while that of the German strain is only about 43 per cent.4. The difference in the infection rates of the two strains is not due merely to differences in the number of gametocytes formed.5. In general C. pipiens fed on birds infected with the Algerian strain of malaria became more heavily infected than those fed on birds infected with the German strain.6. C. pipiens were infected in some cases by feeding on birds with chronic infections of the Algerian strain of P. relictum, but not when fed on birds with chronic infections of the German strain.7. No seasonal influence was found as regards the infection of C. pipiens by P. relictum.8. The Algerian strain of malaria was successfully transmitted by English, Greek, Hungarian, Maltese and Greek-Hungarian strains of C. pipiens, and the German strain of malaria by English, Greek, Maltese and Greek-English strains of C. pipiens.

Chemotherapy and avian malaria

“…. Results of experiments by Tate & Vincent (19346) on the action of atebrin upon P. relictum, transmitted to canaries by blood inoculation, were in accord with those of Kikuth. They too found that, when given prophylactically by Roehl's method, though it delayed the appearance of parasites in the peripheral blood it was unable to prevent infection.…”

“…Such an autogenous race is part of our equipment for insect transmission experiments. Tate & Vincent (1934a) found no difference in susceptibility in the autogenous and anautogenous strains of Culex pipiens to the same strain of Chemotherapy and avion malaria Plasmodium telictum, nor in their ability to transmit the infection. But two strains of P. relictum, a German strain, the gift of the late Dr Roehl, and an Algerian strain, the gift of Prof. Ed.…”

“…They attributed the delaying action of atebrin upon the parasites to its slow excretion from the body, a characteristic which had been demonstrated by several workers. Tate & Vincent (19346) found no evidence of such a clinical prophylactic action of atebrin upon infections of P. relictum transmitted to canaries by. the bite of Culex pipiens.…”

“…The drugs were injected subcutaneously (Giemsa, Weise & Tropp, 1926), intramuscularly (Kritschewski & Sternberg, 1933), or orally (Goodson et al 1930;Buttle, Henry & Trevan, 1934;Buttle, Henry, Solomon, Trevan & Gibbs, 1938;Tate & Vincent, 1933a). Whereas some workers have studied the curative action of the drugs others have studied their prophylactic action.…”

On Two Subspecies of Culex Pipiens L (Diptera)

“…He found that under laboratory conditions its biology was similar to that of the French strain described by Roubaud. I n the same year this mosquito was found by Vincent (1933) in Hungary, and by Tate and Vincent (1934) in Greece and Malta. Roubaud (1933) gave a more complete account of the biology of the two races and named the man-biting, autogenous mosquito C. pipiens autogenicus and the man-ignoring, anautogenous one C. pipiens pipiens L.…”