Browsing by Author "Dai, Shu-Mei"

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Comparative Demography and Mass Rearing of Aedes Aegypti Fed on Different Food Sources Using a Novel Perforated Feeder
(E Schweizerbartsche verlagsbuchhandlung, 2022) Hsu, Pei -Chen; Atlihan, Remzi; Chi, Hsin; Dai, Shu-Mei
A novel thermal-constant blood-feeder covered with a perforated film and using pig blood was developed for rearing Aedes aegypti (L.) (Diptera: Culicidae). The perforated film was used as a substitute for the membrane or parafilm that is normally used in conventional blood-feeders to prevent the mosquitoes from directly contacting the blood. The efficiency of this perforated blood feeder was assessed by using live mice and comparing the engorgement rate of female mosquitoes and their demographic parameters. In a no-choice test, no significant differences were observed in the engorgement rates and fecundity between females fed on perforated feeders containing pig blood and those fed on live mice. In a three-minute-long free-choice test, the accumulated engorgement rate was significantly higher in mosquitoes feeding on the perforated feeders than in those feeding on live mice. The demographic characteristics indicated that mosquitoes fed on the perforated feeder containing pig blood had a higher immature survival rate and prolonged adult male and female longevity. Although a lower intrinsic rate of increase and lower finite rate of increase were observed when female adults fed on the perforated feeder, computer projection of the population growth was comparable using both blood sources. Massn acing analysis showed that the perforated blood feeder was much more cost-effective than using live mice. These results demonstrate that the perforated blood feeder containing pig blood is more effective and cost efficient than using live mice for maintaining and mass rearing of mosquitoes in the laboratory.
Genetically Engineered Ricin Suppresses Bactrocera Dorsalis (Diptera: Tephritidae) Based on Demographic Analysis of Group-Reared Life Table
(Oxford Univ Press inc, 2016) Chang, Cheng; Huang, Chun-Yen; Dai, Shu-Mei; Atlihan, Remzi; Chi, Hsin
The oriental fruit fly, Bactrocera dorsalis (Hendel), reduces the quantity and quality of many host fruits through the process of oviposition and larval feeding, and this insect has been considered a major insect pest in several Asian countries for decades. Using an earlier-developed, female-specific system that combines the toxicity of the ricin A chain (RTA) and the alternative RNA splicing property of doublesex (Bddsx), we show that transgenic male flies harboring the RTA-Bddsx transgene unevenly repress the pest population through inheritable effects. In age-stage, two-sex life-table analyses, high larval mortality and a delay in pupation were observed after introducing the transgene. The high male to female ratio in DsRed(+) flies demonstrates the lethal effect of ricin on females. The fitness of both the DsRed(+)- and DsRed(-)-transformed females was reduced as shown in the decrease of the net reproductive rate (R-0), intrinsic rate (r), and finite rate (lambda) values compared with the wild-type populations. The integrity of the RTA-Bddsx transgene remained in more than 80% of DsRed(+) males after ten generations, supporting the stable inheritance of the transgene. All of the data from this study support the proposed RTA-Bddsx SIT approach, which provides a species-specific and environmentally friendly method of suppressing, rather than eradiating, B. dorsalis.