Journal of Taiwan Agricultural Research

Author:Hsin-Shun Lai, Yi-Ju Chen, Yi-Chung Chiu, and Feng-Chyi Lin*

Abstract:

    Scirtothrips dorsalis Hood was raised at 16, 20, 24, 28, 32, 34 and 36℃ on mango (Mangifera indica L.) to observe the effect of temperature on the developmental times of the immature stages and estimate the population parameters of S. dorsalis at 20, 24, 28, 32 and 34℃ . The results showed that developmental time of egg, first larva, second larva, pupa and egg to adult stage were 4.1–19.1 d, 1.4–5.7 d, 1.3–8.2 d, 1.5–7.9 d and 8.5–42.0 d at 16–36℃ , respectively. The thermal summation was 206.14 degree-days and the low temperature threshold was 10.7℃ as calculated by linear regression analysis. The low temperature threshold was 10.6℃ and the optimal temperature was 35.6℃ as calculated by Lactin-2 nonlinear regression analysis. Population parameters at different temperatures on S. dorsalis showed that both the intrinsic rate of increase (r_m) and the finite rate of increase (λ) were the highest at 28℃ (r_m = 0.2009 d^-1, λ = 1.2226 d^-1), and the lowest was at 20℃ (r_m = 0.0824 d^-1, λ = 1.0859 d^-1). The reproductive rate (R₀) was the largest at 28℃ (R₀ = 40.82 offspring/♀), and the smallest was at 34℃ (R₀ = 4.14 offspring/♀). The mean generation time (T) was the longest at 20℃ (T = 32.77 d), and the shortest at 34℃ (T = 12.15 d).

Key words:Scirtothrips dorsalis, Mango, Temperature, Developmental rate, Life table

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