Effects of Temperature and Larval Diet on ...

16 441 Medical and Veterinary Entomology (2000) 14, 31-37

205310

Effects of temperature and larval diet on development rates and survival of the dengue vector Aedes aegypti in north Queensland, Australia W. TUN - LIN 1, T. R. BUR K 0 T 2 and B. H. KAY The Queensland Institute of Medical Research and The University of Queensland, Tropical Health Program, P.O. Royal Brisbane Hospital, Queensland, Australia

Abstract. Immature development times, survival rates and adult size (winglengths) of the mosquito Aedes aegypti (L.) (Diptera: Culicidae) were studied in the laboratory at temperatures of 10-40°C. The duration of development from egg eclosion (hatching of the first instar) to adult was inversely related to temperature, ranging from 7.2 ± 0.2 days at 35°C to 39.7 ± 2.3 days at 15°C. The minimum temperature threshold for development (t) was determined as 8.3 ± 3.6°C and the thermal constant (K) was 181.2 ± 36.1 day-degrees above the threshold. Maximum survival rates of 88-93% were obtained between 20 and 30°C. Wing-length was inversely related to temperature. The sex ratio (

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Water temperature (oe)

Habitat symbols: opot plant bases, o striking containers, t:. lyres, v ice-cream tubs, [J drums, I!l tanks, 0 buckets, .. lyres under trees, ... lyres under shed, " ice-cream tubs under trees, v ice-cream tubs under shed, • pot plant bases on verandah (open symbol = exposed site, closed symbol = covered site).

Field studies

Fig.3. Comparison of percentage survival ::': SD of Ae. aegypti (Townsville strain) from first stage larvae to adulthood from field containers, compared to. the laboratory survival curve for Thursday Island strain.

Duration of development (Fig. 1, Table 2) varied by container position and hence water temperature. Duration

Table2. Mean instar duration (days) and percentage survival of immature stages of Ae. aegypti reared at different temperatures at Charters Towers (CT) and Townsville (T). Mean duration (::': SO) of each stage (days) Container type (no. examined) Car tyres exposed (4) under trees (2) under shed (2) under trees (4) exposed Plastic containers (4) Pot plant bases exposed (4) verandah (4) Ice-cream tubs exposed (2) under shed (2) under trees (4) Metal drums exposed (4) Rainwater tank (2) Buckets open (4)

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Total duration

2.6::': 0.2 2.2::': 0.1 2.9::': 0.2 2.9::': 0.2

3.3 ::':0.2 2.3::': 0.1 4.5::': 0.5 1.5::': 0.3

4.5::': 1.2 3.0::': 0.1 5.8::': 0.9 3.1 ::': 0.1

6.1 ::': 1.5 4.5 ::':0.6 3.4::': 04 1.8::': 0.4

19.9::': 2.6 15.3::': 0.7 19.6::': LO 12.3::': 0.0

9.9±0.1

6.0::': 0.3

5.7::': 0.1

21.6::': 0.2

63.8::': 5.6 59.1::': 5.6 73.2::': 4.1 87.0::': 3.9 21.0::': 7.0 51.7 ::':4.0

3.8 ± 0.2

10.7 ± 0.4 4.3 ± 0.2 4.5 ± 0.4

13.3::': 0.5 3.9 ± 0.5 6.3 ± 0.6 3.5 ± 1.2

27.9 ±0.6 22.4::': 0.5

32.7 ± 5.0 41.0::': 1.5

20.1 ± 2.6 17.4 ± 2.4 25.8::': 1.0

3.3 ±O.I

9.5 ± 0.1 8.7 ± 1.2 1.6 ± 0.1 1.6 ± 0.1

6.5 ± 1.0 9.3 ± 0.3 2.2 ± 0.5

5.5 ± 0.2 5.1 ± 2.0 2.7 ::':0.5

21.5::': 0.6 23.2 ±0.5 11.3 ± 1.1

42.5::': 7.1 62.0 ± 5.0 95.0 ± 1.5

20.2 ± 3.4 26.7 ± 1.8 19.3 ± 3.4

3.9 ± 0.0 2.1::': 0.0 3.0 ± 0.1

2.6±0.1 1.7::': 0.1 1.5 ± 0.1

3.6::': 0.1 2.9::': 1.7 5.5::': 0.0

3.2 ± 0.7 2.9 ± 0.6 3.5::': 0.1

15.6 ± 0.9 11.0::': 1.3 19.8::': 0.4

56.0 ±II.O 72.4::': 4.2 31.0 ± 12.7

Locality and date

Water temp. (::': SD)

CT, May 1990 CT, May 1990 CT, May 1990 T, Feb 1989 CT, May 1990 CT, May 1990

20.7::': 2.9 18.1 ::': 3.1 20.0::': 4.1 25.3::': 1.0 20.7::': 2.9 16.6::': 2.6

CT, May 1990 T, Feb 1989

16.3::': 2.7 28.1 ± 1.0

CT, May '90 CT, May '90 T, Feb '89 CT, May '90 CT, May '90 CT, May '90

3.4::': 0.2 3.4::': 0.1 3.0::': 0.2 3.0::': 0.1

2.4± 0.2 1.3 ± 0.2 6.2 ± 0.5

Survival %

C 2000 Blackwell Science Ltd, Medical and Veterinary Entomology, 14, 31-37

Aedes aegypti development and survival 4.0

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