Evaluation of the effect of horse blood supplemented with human blood and vitamin on the performance of Glossina morsitans morsitans colony

The study was conducted to evaluate the effect of horse blood supplemented with human blood and vitamin on the performance of Glossina morsitans morsitans colony. Three feeding groups were established and a total of 144 female G. m. morsitans flies were assigned to each group. The first group was entirely maintained on defibrinated horse blood, while the second and third groups fed horse blood with one feed per week on human blood and vitamin supplement respectively. The result of the study showed no difference in mortality between the flies fed human blood and vitamin supplement (p = 0.807) but vitamin supplement (p = 0.002) and human blood supplement (p = 0.006) produced significantly greater mortalities than the horse blood. The flies fed horse blood performed better than human blood supplement and vitamin supplement in terms of female survival (p=0.002), pupal weight (p< 0.001) and emergence (p = 0.029). Abortion was low throughout and not significantly different (p = 0.548) between the three feeding groups. Similarly no difference was found in pupae production between the flies fed horse blood and human blood supplement but both of these produced significantly more pupae than vitamin supplement (p = 0.002). The flies fed human blood supplement produced large numbers of pupae but of lighter weight and with low emergence. The emergence of the flies from the pupae produced by the flies fed horse blood, vitamin supplement and human blood were 97.2%, 91.1% and 90.1% respectively. According to the study, horse blood was the best diet of the three and recommended for colony feeding while human blood supplement is nutritionally poor. On the other hand, vitamin supplement did not improve the nutritional quality of horse blood, but on balance deteriorated the nutritional quality of the meal.Keywords: Colony performance, Feeding regime, Glossina morsitans morsitan, Horse blood, Human blood supplement, Vitamin supplemen

The dynamics of TseTse Fly in and around intensive suppression area of Southern Tsetse Eradication Project Site, Ethiopia

This study was carried out in and around intensive suppression area of the Southern Tsetse Eradication Project in Gamo Goffa Zone, Southern Nations, Nationalities and people`s Region of Ethiopia. Assessment of the dynamics of the vector tsetse was done by entomological survey between December-Jan, 2008 (dry season) and April-May, 2009 (wet season) in and around the intensive suppression area of the project site. The entomological survey revealed the presence of Glossinapallidipes as the only Glossina species in the study area. Total catch of flies were 95 and zero with averages of apparent densities of 1.6 and zero flies per trap per day during dry and wet seasons, respectively in ISA and a total catch of 8417 and 2028 with averages of apparent densities of 280.6 and 67.6 flies per trap per day in dry and wet seasons, respectively in Nech Sar National Park. In conclusion, results of seasonal and spatial dynamics of tsetse flies in intensive suppression areas and Nech Sar National Park, would be useful in planning an eradication program in the project area. Large population of tsetse flies in the Nech Sar National Park poses a risk of reinvasion and the uncontrolled animal movements in the project area may challenge the efficiency of the project.Generally continuous control and monitoring activities in the project area should be evaluated periodically and effectiveness of each control measures in specified sites must be seen in a favor of eradication program.The study would help in dynamic approach of the project planning, implementation, monitoring and evaluation.Keywords: Apparent density, Cattle, Intensive Suppression Area, Nech Sar National Park, Tsetse dynamics

Cryptic diversity within the major trypanosomiasis vector Glossina fuscipes revealed by molecular markers

Background: The tsetse fly Glossina fuscipes s.l. is responsible for the transmission of approximately 90% of cases of human African trypanosomiasis (HAT) or sleeping sickness. Three G. fuscipes subspecies have been described, primarily based upon subtle differences in the morphology of their genitalia. Here we describe a study conducted across the range of this important vector to determine whether molecular evidence generated from nuclear DNA (microsatellites and gene sequence information), mitochondrial DNA and symbiont DNA support the existence of these taxa as discrete taxonomic units. Principal Findings: The nuclear ribosomal Internal transcribed spacer 1 (ITS1) provided support for the three subspecies. However nuclear and mitochondrial sequence data did not support the monophyly of the morphological subspecies G. f.fuscipes or G. f. quanzensis. Instead, the most strongly supported monophyletic group was comprised of flies sampled fromEthiopia. Maternally inherited loci (mtDNA and symbiont) also suggested monophyly of a group from Lake Victoria basin and Tanzania, but this group was not supported by nuclear loci, suggesting different histories of these markers. Microsatellite data confirmed strong structuring across the range of G. fuscipes s.l., and was useful for deriving the interrelationship of closely related populations. Conclusion/Significance: We propose that the morphological classification alone is not used to classify populations of G. fuscipes for control purposes. The Ethiopian population, which is scheduled to be the target of a sterile insect release (SIT) programme, was notably discrete. From a programmatic perspective this may be both positive, given that it may reflect limited migration into the area or negative if the high levels of differentiation are also reflected in reproductive isolation between this population and the flies to be used in the release programme

Intrinsic and Synthetic Stable Isotope Marking of Tsetse Flies

The sterile insect technique has been successfully used to eliminate tsetse populations in a number of programs. Program monitoring in the field relies on the ability to accurately differentiate released sterile insects from wild insects so that estimates can be made of the ratio of sterile males to wild males. Typically, released flies are marked with a dye, which is not always reliable. The difference in isotopic signatures between wild and factory-reared populations could be a reliable and intrinsic secondary marker to complement existing marking methods. Isotopic signatures are natural differences in stable isotope composition of organisms due to discrimination against the heavier isotopes during some biological processes. As the isotopic signature of an organism is mainly dependent on what it eats; by feeding factory-reared flies isotopically different diets to those of the wild population it is possible to intrinsically mark the flies. To test this approach unlabeled samples of Glossina pallidipes (Austen) (Diptera: Glossinidae) from a mass rearing facility and wild populations were analyzed to determine whether there were any natural differences in signatures that could be used as markers. In addition experiments were conducted in which the blood diet was supplemented with isotopically enriched compounds and the persistence of the marker in the offspring determined. There were distinct natural isotopic differences between factory reared and wild tsetse populations that could be reliably used as population markers. It was also possible to rear artificially isotopically labeled flies using simple technology and these flies were clearly distinguishable from wild populations with greater than 95% certainty after 85 days of “release”. These techniques could be readily adopted for use in SIT programs as complimentary marking techniques