The effects of low temperatures on larval survival of Aedes aegypti and Ae. albopictus (Diptera: Culicidae) in Taiwan
Date Issued
2006
Date
2006
Author(s)
Chang, Lun-Hsien
DOI
en-US
Abstract
Aedes aegypti and Ae. albopictus differ in their distribution in Taiwan. The former species is distributed only in the south of Taiwan while the latter is found island-wide. One of the possible explanations proposed is that low temperature in winter to prevent the colonization by Ae. aegypti. Hence, the impact of low temperatures on immatures of both species is studied here in the laboratory
and field. In laboratory experiments, first and fourth instar larvae were exposed to low temperatures for various times. I estimated the lethal time that could kill 50% of populations (LT50) using linear regression. For the first instar larvae, Ae. albopictus was more tolerant than Ae. aegypti at temperatures of 2.5, 5 and 10oC. First instar larvae of Ae. albopictus showed remarkable tolerance at 10oC and the LT50 was estimated to be 526 hours, which is five times to that of Ae. aegypti. For fourth instars, Ae.aegypti had greater tolerance than Ae. albopictus at 2.5 and 5oC, but Ae. albopictus had a greater tolerance at 10oC. First instars were selected at 5oC over four generations. Both species showed more tolerance after selection. Aedes aegypti showed a greater mortality than Ae. albopictus during exposure to cold fronts but the opposite was true in the absence of a cold front. The lethal effect of cold fronts on Ae. aegypti was identified from their daily mortality. My studies suggest that winter temperature in the north part of Taiwan may have a significant effect on the distribution of Ae. aegypti in Taiwan.
Subjects
埃及斑蚊
白線斑蚊
存活率
低溫
50%致死時間
耐寒能力
Aedes aegypti
Ae. albopictus
survival
low temperature
LT50
tolerance to low
Type
thesis