| Budget Amount *help |
¥2,100,000 (Direct Cost: ¥2,100,000)
Fiscal Year 1997: ¥900,000 (Direct Cost: ¥900,000)
Fiscal Year 1996: ¥1,200,000 (Direct Cost: ¥1,200,000)
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| Research Abstract |
Relation between temparature and immature develpment was analyzed for 32 mosquito species (13 Aedes, 7 Culex, 7 Anopheles, 1 Culiseta, 2 Toxorhynchites, 2 Psorophora) based on literat ure data. (1) Developmental thresholds of Aedes and Culiseta species of the subarctic zone are c a.5ﾟC or lower and destinctly lower than temperate, subtropical and tropical species. (2) Devel opmental thresholds of temperate, subtropical and tropical species are ca. 10ﾟC or higher. Species of warmer regions do not necessarily have higher developmental thresholes. (3) Intra-specific variations for developmental thersholds are not recognized.(4) There are a few old data for tropical and subtropical species. This lack must be fulfillled, because those species are most dangerous from the view point of global warming.
Laboratory experiments for cold-and drought-resistance of non-diapause eggs were performed for 7 species (14 starins) of Aedes (stegomyia) species. Species included are ; Aedes paullusi (distribu
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tion tropcal), Aedes scutelaris (torpical), Aedes aegypti (tropical-subtropical), Aedes albopictus (tropical-warm temperate), Aedes riversi (subtropical-warm temparate), Aedes flavopictus (subtropical-cold temparate), Aedes galloisi (cold temparate). (1) Aedes paullusi and Aedes scutellaris can survive for a few days under sub-zero temparatures if humidities are high. (2) Aedes aegypti can survive at least for several days under sub-zero temparatures. This speoies has high drought-resistance. (3) Aedes albopictus show intra-specific variation in cold-resistance. Starins from temperate regions can survive at least for 20 days under sub-zero temparatures. This species has drought-resistance ability next to Aedea aegypti. (4) Both subtro pical and temperate strains of Aedes riversi and Aedes flavopictus has cold-resistance ability comparable to temparate stains of Aedes albopictus. These species are less resistant to drouget. (5) Aedes galloisi is most resistant to coldness, being capable of suvival for more than 2 months under sub-zero temparatures. This species is least resistant to drought. (6) Capability of eggs to survive under sub-zero temperatures is an improtant attribute determining geographica 1 distribustions but real distributions may be narrower than expected from cold resistace ability due to factors other than cold resistance.
The results will be used for prediction of impact of global warming on geographical distribution of mosquitoes. Less
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