英文摘要 |
"Pieris rapae crucivora Boisduval is one of the important Cruciferae insect pests in Taiwan. Recorded host plants include 14 species in 3 families. The development of P. rapae crucivora was investigated at 4 constant temperatures and 75 %±5 % RH with a 12L: 12D photoperiod using leaves of Brassica campestris. At 15, 20, 25, and 30 °C, the egg stage required 8.2, 6.0, 3.0, and 3.0 days; larval development took 26.9, 19.1, 14.1, and 11.4 days; and pupal development took 15.8, 11.4, 8.1, and 5.9 days, respectively. Adults had longevities of 16.4, 19.3, 7.0, and 4.1 days from 15 to 30 °C. A sex ratio of 1.1: 1 (♀: ♂) was estimated by the number of adults which emerged. Numbers of eggs laid by a female at 20, 25 and 30 °C were 64.3±39.6, 46.5±49.8, and 6.3±6.8, respectively. The threshold of development temperature and the effective accumulated temperature for the egg stage were 7.38 °C and 64.73 degree-days (DD). The temperature of the development threshold for the first- to the fifth-instar larvae were estimated to be 9.41, 10.96, 8.06, 5.34, and -5.0 °C, respectively, while the sums of the effective accumulated temperature were 44.91, 19.94, 28.19, 46.04, and 166.63 DD, respectively. For larvae, the threshold temperature was 4.67 °C, and the effective accumulated temperature was 286.50 DD. For the pupal stage, the threshold temperature was 7.43 °C, and the effective accumulated temperature was 134.60 DD. The external morphology at each stage for this butterfly is also described and illustrated in the paper." |