Tag: William Bradshaw

Use of Dichloro-diphenyl-trichloro-ethane and Alternative Methods to Fight Malaria in Sub- Saharan Africa

Presenter(s): Sarah Wheeler − Biology

Faculty Mentor(s): William Bradshaw, Melissa Graboyes

Poster 17

Research Area: Natural/Physical Science

Malaria is a disease that seems foreign to many; a distant memory. Despite the lack of awareness of the breadth of this disease, the World Health Organization reported 216 million cases of malaria across the world in 2016, 445,000 of which resulted in fatalities. While malaria was eradicated in the US in 1951, it’s present across the globe, with the epicenter of the endemic in Sub-Saharan Africa. Malaria is a vector-borne disease, meaning an organism transfers the disease to a host.
The vector for malaria is Anopheles gambiae, which infects the host with the parasite Plasmodium. Eradication has been successful through the use of dichloro-diphenyl-trichloro-ethane (DDT) by spraying the interior of homes in the past, but the organic pesticide has been banned in many countries. This research focuses on how eradication occurred in the past, what is used today to fight malaria in Sub-Saharan Africa and methods currently being developed in laboratories. Specifically, a meta-analysis was conducted of studies concerning the effects of DDT on the environment and human health, mechanisms of A. gambiae mutations that lead to DDT resistance, alternative methods of fighting malaria and their success rate, as well as cultural and financial barriers that prevent eradication. Comparison of these studies suggests that a rotation of pesticides, including DDT in IRS is effective when paired with pesticide-treated nets.

Developmental Synchronization Of The Purple Pitcher Plant Mosquito, Wyeomyia Smithii, as a Result Of Increasing Temperatures

Presenter(s): Kevin Spies − Biochemistry

Faculty Mentor(s): William Bradshaw, Christina Holzapfel

Poster 45

Research Area: Natural Science

The environment factor of temperature plays an important role in the growth and development of ectothermic species. In many species, increasing temperatures have been shown to dictate development rates and gives rise to the synchronization of the mature adults from adolescence. In the purple pitcher plant mosquito Wyeomyia smithii, this phenomenon has not yet been determined to occur. The goal of this research project is to determine whether synchronized development occurs in W. smithii as a result of increasing temperatures. Accurate determination of this adaptation in W. smithii may have important implications in evolutionary biology including being used as a foundation for locating synchronization genes and adding to the current literature for synchronized emergence and the rule of thermal summing. Additionally, this information may aid in the preservation of agricultural crops against W. smithii infestation and may serve as a means of vector control for mosquito- borne disease. The project encompasses subjecting four distinct W. smithii populations to light-controlled incubators (programmed light:day cycle of 18:6) with increasing temperatures from 4 °C to 30 °C. Two cohorts from each population will be introduced to the 4 °C environment; every fifth day, the temperature will increase 2 °C and two cohorts from each population will be placed in the incubator. All populations will be observed for signs of development. Once all W. smithii have reached maturity, data will be undergo an analysis of covariance to determine whether or not synchronized development and emergence has occur in W. smithii.

Determining growth and development in Wyeomyia smithii mosquitoes using fluctuating temperatures

Presenter(s): Danielia Lewis

Faculty Mentor(s): William Bradshaw & Chris Holzapfel-Bradshaw

Oral Session 1 O

Mosquito bites cause over one million deaths per year by spreading blood-borne diseases like malaria, and yellow fever. Synchronous emergence in the spring facilitates males finding mates and also saturating the ability of predators to consume all of the emerging insects (predator satiation). With mass swarming, it ensures that some, or many, of the potential prey will escape predation and reproduce. The ability to predict mass emergence of disease vectors increases the efficacy of control measures, whether by sterile males, toxic baits, or conventional pesticides. Using two northern and two southern populations of the pitcher-plant mosquito, Wyeomyia smithii, I determined the degree of synchronization of development by using realistic, fluctuating temperatures simulating a temperate spring environment. I found that hibernating individuals that started development at warmer temperatures later in the spring developed faster than individuals that started development at cooler temperatures earlier in the spring, both in northern and southern populations. This difference led to later developing mosquitoes “catching up” to those that started development earlier. We call this passive synchronizing effect of warming environments “autosynchronization.” The autosychonization effect was apparent within both southern and northern populations.

These results demonstrate the autosychronization effect, but this effect was not able to synchronize the developmentally conservative northern populations with the more developmentally progressive southern populations, even when encountering the same warming spring environment. The efficient timing of mosquito control efforts will be highly applicable within climatic zones but not between climatic zones due to differences in the developmental physiology of target organisms.