| Summary: | 碩士 === 國立屏東科技大學 === 熱帶農業暨國際合作研究所 === 93 === Chromolaena odorata (L.) introduced around 1989 to southern part of Taiwan as a medicinal plant, has become an invasive weed, spreading to such counties as Pingtung, Kaohsiung, Tainan, Chiayi, Yunlin, Changhau, Taichung, and Taitung. An arctiid moth, Pareuchaetes pseudoinsulata Rego Barros, was introduced from Guam in June 2004 and was immediately isolated for study host specificity and other research in a quarantine laboratory at National Pingtung University of Science and Technology. The life history of P. pseudoinsulata feeding on C. odorata was studied at three different temperatures. Developmental time from egg to adult was 69.5, 40.7 and 39.4 days for female; and 66.8, 38.9 and 41.0 days for male, at 24, 28 and 32℃, respectively. Under the temperatures of 24, 28 and 32℃, the longeyity of P. pseudoinsulata was 13.1, 7.6 and 3.8 days for female, and 11.1, 5.8 and 3.8 days for male, respectively. Pre-oviposition periods and fecundity for P. pseudoinsulata averaged 54.4, 37.4 and 38.1 days, and 389.3, 261.8 and 159.0 eggs per female, respectively. Population parameters were caculated from the life table data for 24, 28 and 32℃. Under the respective temperatures, the net reproduction rates (R0) of P. pseudoinsulata were 279.9, 176.1 and 14.5; the mean generation time (T) were 57.9, 38.0 and 34.2 days; the intrinsic rates of increase (rm) were 0.099, 0.138 and 0.078; the finite rates of increase (λ) were 1.103, 1.146 and 1.082；Doubling times (t) were 7.1, 5.1 and 8.8 days. The age-stable distribution of P. pseudoinsulata under the three different temperatures was significantly different. The larval stage was dominant at 24℃. The larval and adult stages were dominant at 28℃. The larval and pupal stages were dominant at 32℃. In the feeding study, the amount of leaf consumed was the greatest at the late larval stage; each larva consumed 0.57, 0.69 and 0.24g at 24, 28 and 32℃, respectively. A total of 135 plant species in 55 families have been screened by forced feeding for delineating the host specificity of P. pseudoinsulata. Of the plant species screened, larvae of P. pseudoinsulata were found feeding on C. odorata (L.), Ageratum conyzoides L., A. houstonianum Mill, and Eupatorium formosanum Hayata. However, they did not feed or not attempt to feed on 132 other plant species screened.
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