抄録
Results of two mosquito studies recently conducted in a park in urban Tokyo were introduced and related studies were reviewed. A large number of adult Culex tritaeniorhynchus suddenly appeared from late September to November 2007 during the course of systematic sweep net collections of vegetation in the park. The pre-diapause migration has been observed every year from 2007 to 2010. The time course of pre-diapause migration was similar starting in mid-/late September, peaking in mid-October and ending in December. The density of migrated females and parity differed year by year, and dissection showed that a large part of the females (85 to 97%) were in reproductive diapause. Blood-meal identifications of Cx. pipiens pallens together with avian malaria parasite detection were conducted by using blood-fed females collected in the study park from May 2007 to May 2008. Thirteen wild bird species were identified as the blood-source and 5 of them were infected with avian malaria parasite. Ten Plasmodium lineages were identified and the three commonest lineages were detected in both the abdomens and thoraxes of mosquitoes, suggested transmission of these lineages. Jungle crow and tree sparrow served as a natural host for the three commonest lineages.
