1.It has been found that yellow fever virus may remain alive in ticks for considerable periods. The persistence of the virus has been demonstrated by the injection of tick suspensions into M. rhesus monkeys.
2.Adult Argas persicus injected six days after the infective blood meal caused fatal yellow fever.
3.Adult Amblyomma cajennense injected fifteen days after the infective blood meal caused fatal yellow fever. Injection of ticks from the same lot after twenty-eight days gave rise to immunity without clinical indications of disease.
4.Adult Rhipicephalus sanguineus injected twenty-three days after the infective blood meal caused fatal yellow fever. Injection of R. sanguineus nymphs ten days after the infective feeding produced a like result.
5.Larvae of Boophilus microplus injected ten days after the infective blood meal caused fatal yellow fever.
6.Chicken mites (genus and species not determined) injected six days after the infective blood meal caused fatal yellow fever.
7.In a limited number of experiments no evidence was secured that yellow fever virus was passed from one generation of tick to another through the egg, that virus persisted through the transformation of larva to nymph, or that virus was transmitted by the bites of infected ticks at any stage of life.