Abstract
This study has the overall goal to develop and improve mass-rearing of the SuperMosqTM bio-products or sterile male mosquitoes produced either by Sterile Insect Technique (SIT) through low-dose irradiation or by Wolbachia-induced Incompatible Insect Technique (IIT). The specific objectives are as follows: 1) develop a high-quality, low-cost, industrial scale, Aedes aegypti larval diet, 2) develop a local sex separator device for separating Ae. aegypti male and female pupae, 3) test yeast proteins for blood meal replacement of female mosquitoes, and 4) assess quality control of mass-reared immatures and sterile mosquitoes. For the development of Ae. aegypti larval diets, it was found that an alternative larval diet had very little effect on the growth and development of both male and female pupae and adults when compared to those that were reared with the standard larval diet. Moreover, when the cost of the diet was taken into consideration, it was found that the cost of an alternative larval diet was 60% lower than that of the standard diet. Therefore, it was concluded that an alternative larval diet could be applied for mass production of mosquitoes at the industrial scale as it reduces the cost of production but still yield good quality of mosquitoes. For the development of local pupal sex separator device, It was found that there was no significant different in the efficacy between the local pupal sex separator and the imported one. When the speed of sex separation and the percentage of female contamination, together with other factors such as cost, transportation, maintenance, etc. was considered, it was found that there were no significant differences in the speed of sex separation and the percentage of female contamination while the cost of the locally assembled device was 70% lower. For the development of yeast protein Ae. aegypti females, it was found that the yeast protein diet was not able to replace the general blood meal as females could not lay eggs when they were fed with the yeast protein diet. Besides, Ae. aegypti females were less attractive to the yeast protein diet when compared to the pig blood. In addition, females that were fed on the yeast protein diet were unable to produce eggs. Therefore, it is necessary to study and find other raw materials in order to improve and develop recipes that could be used to replace blood in the future. For quality control of sterile male mosquitoes using flight ability test, it was found that there was no significant difference in the escape rate of the sterile mosquitoes produced from both low-dose irradiation and Wolbachia-induced incompatibility, or the SuperMosqTM bio-products, when compared to the control ones. Therefore, it could be concluded that the low-dose irradiation and the presence of Wolbachia bacteria did not affect the flight ability of the SuperMosqTM bio-products. For quality control of sterile male mosquitoes using sterility test, it was found that sterile mosquitoes, whether they were sterile by either low-dose irradiation or by Wolbchia-induced incompatibility, could make fertile Ae. aegypti females sterile; as the latter lay unhatched eggs or even could not produce eggs at all. In other words, it could be concluded that the SuperMosqTM bio-products, sterilized by either low-dose irradiation or Wolbachia-induced incompatibility, can cause sterility in the fertile Ae. aegypti females when they were mated and that the females could not produce any offspring. For quality control of sterile male mosquitoes by assessing male mating competitiveness, it was found that both radio-sterilized and Wolbachia-induced incompatible males had nearly similar ability to compete with wild males in order to mate with Ae. aegypti females. Therefore, when the SuperMosqTM bio-products were applied for vector control, they should be released in a ratio equal to 10 times of the number of wild males in the case radio-sterilized males and only one time of the number of wild males in the case of Wolbachia-induced incompatible males, in order to effectively compete with wild Ae. aegypti male mosquitoes. For quality control of sterile male mosquitoes by assessing survival rate and life expectancy, it was found that low-dose irradiation had no effect on average survival rate and life expectancy of sterile males when compared to the control ones, while those that were sterilized by Wolbachia-induced incompatibility reduced average survival rates and shortened the life expectancy of sterile males when compared to the control ones. For quality control of sterile male mosquitoes by detection of Wolbachia bacteria, it was found that Wolbachia bacteria was 100% present in the sterile males that were randomly selected for detection in every lots of productions. Therefore, it could be concluded that Wolbachia bacteria was stably established in the SuperMosqTM bio-products.
