Field Trial of New Technologies for Reducing Mosquito Populations in Bulloch County, Georgia, USA

Mosquito-borne diseases such as West Nile virus and Eastern Equine Encephalitis virus pose an important health risk to residents and travelers to southeastern Georgia. There is an increasing threat of introduction of mosquito-borne diseases, such as Zika and dengue virus, into Georgia where susceptible mosquito species are present. A field trial of the ProVector Tube Applicator with Entobac D pesticide was conducted to determine if the system was effective in reducing mosquito populations in Bulloch County, located in southeastern Georgia. Within one month, there was a significant difference in reduction of mosquitoes in the test versus the control sites, 93% versus 1%, respectively. There was a significant reduction in the test but not the control every two weeks. Providing effective, inexpensive, safe and eco-friendly tools for officials and homeowners is necessary in the event local mosquito control is poorly funded.


INTRODUCTION
Nearly 4 billion people are at risk from vector-borne diseases (VBD), with VBD's accounting for more than 17% of all infectious disease cases being causedglobally (WHO 2017). Malaria, filariasis and arboviruses, such as dengue, yellow fever virus, Chikungunya, Zika, and Ross River infect millions annually. Mosquitoborne diseases also have an impact on domestic animals as well, such as equine encephalitis viruses and heart worm. Mosquito-borne diseases have significant impact on health in the United States, West Nile, Eastern Equine Encephalitis, La Crosse, St. Louis, and dengue occurring in several states. Zika virus is also an important emerging infectious disease in the United States, particularly in Florida and Texas.
Along with habitat and host species, temperature, humidity, precipitation, are all important factors in determining the presence and abundance of mosquito species in Georgia (Buckner et al. 2011). A number of MBD's occur in Georgia, West Nile virus being the most common, but when cases of Eastern equine encephalitis (EEE) virus occur, the impact on the patient and their family members can be devastating. West Nile virus and EEE are currently a significant health risk in Bulloch County, Georgia. Preventing the introduction of mosquito-borne arboviruses, such as dengue, Chikungunya and Zika, along with the presence of competent vectors poses a challenge to public health officials and families. Many counties in the state of Georgia do not have a robust mosquito control division, Bulloch County is among them. Without an official integrated mosquito management plan, finding cheap, safe, and environmentally friendly options that local officials and citizens can use to rapidly reduce mosquito populations is essential. Here is discussed a new vector controlsystem, consisting of a new applicator and new pesticide, that rapidly reduces mosquito populations and that is flexible enough to be used across habitats and under harsh environmental conditions, and is target specific in delivering a new pesticide to vectors, reducing cost and environmental impact.

II. METHODS
An initial mosquito collection was conducted to get a sample of mosquito populations before deployment of the ProVector® Tube (PVT), Figure 1. Mosquitoes were collected at two test and one control site using one CDC trap and two ABC light traps placed at each site during August and September. Each site measured ½ hectare. Octenol tabs and CO 2 bottle were used as bait on the devices. One CDC and two ABC light traps were also placed, in a similar fashion, at the Control site for two nights each two weeks for one month, Weeks 0, 2 and 4. After the initial mosquito survey, 15 PVT's with Entobac™ D (composed of sugar

III. RESULTS AND DISCUSSION
There was a significant reduction of mosquitoes at the test sites with the PVT's with Entobac D (Figure 2). At the beginning of the study the average number of mosquitoes captured per trap was 8 times higher at test vs control sites. After 4 weeks the mean number of mosquitoes at the sites was nearly identical, 4.8 vs 4.3 ( Figure 2). There was a significant reduction of mosquitoes at the Test but not at the control sites (Table 1). Reducing mosquito populations indoors and outdoors can have a significant impact on malaria and other mosquito-borne diseases. In a study conducted by the Walter Reed Army Institute of Research in Kenya, the ProVector Flower with Entobac (Bti only) was tested against adult mosquitoes. Seven housing compounds with no applicators were included as controls in the study area. After one month, there was a significant reduction of medically important mosquitoes in all nine compounds with the ProVector Flower compared to two of seven control compounds (Chi-square=11. 5 The City of Statesboro, Bulloch County, has a mosquito control program in the Division of Public Works, but funding is very low for mosquito control (personal communication). A systematic mosquito surveillance effort should be conducted to elucidate the species and distribution of mosquitoes and arboviruses in Bulloch County. Citizens living in poor and minority neighborhoods may be at particularly high risk from introduced arboviruses (LaDeau et al. 2013) including neighborhoods in Georgia (Kollars 2017). When there is the detection of a patient infected with an introduced arbovirus, the City of Statesboro can respond quickly, but must import resources from other counties and the federal government. An example of this was an imported case of Chikungunya into Statesboro; Statesboro relied upon the neighboring Mosquito Control Division of Chatham County and the CDC to conduct surveillance and control (personal communication).
Providing inexpensive and ecosafe products may help to protect public health where; mosquito control programs are not available or lack adequate funding and personnel, rapid response with adequate equipment is not available. The ProVector® Tube with Entobac D provides rapid effective control of mosquito populations, while being inexpensive, target specific and environmentally friendly. Additional studies in Bulloch County are being conducted to evaluate new technologies of mosquito control and to identify mosquito species and their distribution in the county.