Enhancing Eastern Equine Encephalitis Virus Surveillance in New Jersey: Optimized Collection of Culiseta Melanura.

Eastern equine encephalitis virus (EEEV) causes the most clinically severe neuroinvasive arboviral disease in the United States. The virus is endemic in eastern and Gulf Coast states and the Great Lakes region, causing cases annually. To detect EEEV circulation in its enzootic cycle before the virus infects humans and other mammals, mosquito control agencies in New Jersey have conducted mosquito surveillance using a series of permanent wooden resting box sites since 1975. We conducted 2 field studies, 1 evaluating resting traps and 1 evaluating efficacy of CO2 lures, to optimize collection of Culiseta melanura, the primary enzootic vector of EEEV. Resulting mosquito samples were subjected to molecular analysis to determine EEEV infection rates. Corrugated plastic boxes trapped more bloodfed Cs. melanura than other resting trap types (resting boxes, Centers for Disease Control and Prevention [CDC] resting traps, or fiber pots) and were similar to resting boxes in total number of female Cs. melanura caught. Further, non-baited CDC light traps were more successful in trapping host-seeking Cs. melanura than those baited with dry ice, a CO2 lure. The EEEV RNA was identified in Cs. melanura, Aedes vexans, Anopheles quadrimaculatus, and Uranotaenia sapphirina. Our findings indicate that corrugated plastic boxes and non-CO2 baited traps could improve detection of Cs. melanura. Mosquito control agencies are encouraged to periodically assess their surveillance strategy for EEEV.

Effectiveness of a Buffalo Turbine and A1 Mist Sprayer for the Areawide Deployment of Larvicide for Mosquito Control in an Urban Residential Setting.

The control of medically important container-inhabiting mosquitoes is an ongoing challenge for mosquito control operations. Truck-mounted application equipment is a common option for rapid areawide larvicide deployment utilized by mosquito control operations. We tested the effectiveness of two truck-mounted sprayers (A1 Super Duty + Buffalo Turbine CSM3), for the deployment of water-dispersible biopesticides (VectoBac WDG:VectoLex WDG 50:50). Sixty residences within four residential neighborhoods in New Jersey were treated in 2019 and 2020. Three empty bioassay cups were placed in specific locations on each property (front yard/ back yard/ side of house), with an additional cup placed in an adjacent catch basin. This approach was replicated in two untreated control neighborhoods. Following larvicide application, cups were subjected to bioassays wherein larval mortality was tracked through adult eclosion. Overall, average larval mortality rates were 56% higher in treated cups compared against untreated controls. Mortality rates were affected by cup location, with 39% mortality in bioassay cups from back yards, 54% in those from the sides of houses, 73% in front yards, and 76% from cups in catch basins. Mortality did not differ significantly between the four treated neighborhoods, nor by the type of sprayer used. Our research shows that truck-mounted sprayers can be an effective method for larvicide deployment in residential neighborhoods, but effectiveness may depend upon the location of the target treatment area in relation to residences and other geographic obstacles.

NEVBD Pesticide Resistance Monitoring Network: Establishing a Centralized Network to Increase Regional Capacity for Pesticide Resistance Detection and Monitoring.

Pesticide resistance in arthropod vectors of disease agents is a growing issue globally. Despite the importance of resistance monitoring to inform mosquito control programs, no regional monitoring programs exist in the United States. The Northeastern Regional Center for Excellence in Vector-Borne Diseases (NEVBD) is a consortium of researchers and public health practitioners with a primary goal of supporting regional vector control activities. NEVBD initiated a pesticide resistance monitoring program to detect resistant mosquito populations throughout the northeastern United States. A regionwide survey was distributed to vector control agencies to determine needs and refine program development and in response, a specimen submission system was established, allowing agencies to submit Culex pipiens (L.) (Diptera:Culicidae) and Aedes albopictus (Skuse) (Diptera: Culicidae) for pesticide resistance testing. NEVBD also established larvicide resistance diagnostics for Bacillus thuringiensis israelensis (Bti) and methoprene. Additional diagnostics were developed for Cx. pipiens resistance to Lysinibacillus sphaericus. We received 58 survey responses, representing at least one agency from each of the 13 northeastern U.S. states. Results indicated that larvicides were deployed more frequently than adulticides, but rarely paired with resistance monitoring. Over 18,000 mosquitoes were tested from six states. Widespread low-level (1 × LC-99) methoprene resistance was detected in Cx. pipiens, but not in Ae. albopictus. No resistance to Bti or L. sphaericus was detected. Resistance to pyrethroids was detected in many locations for both species. Our results highlight the need for increased pesticide resistance testing in the United States and we provide guidance for building a centralized pesticide resistance testing program.

Efficacy of Duet dual-action adulticide against caged Aedes albopictus with the use of an ultra-low volume cold aerosol sprayer.

Duet was field evaluated against caged Aedes albopictus, with the use of a truck-mounted ultra-low volume (ULV) cold aerosol sprayer at the rate of 90.6 ml/ha. Cages were placed in 3 rows stationed 30.5, 61.0, and 91.5 m downwind of the spray vehicle. Initial knockdown was >99% with mortality ranging between 95.8% and 98.0% across the distances. Volume median diameter (VMD) and droplet density were slightly reduced (16.4% and 18.6%, respectively) by distance. Reduction in VMD and droplet density, however, did not reduce mortality. The ULV application of Duet is an effective adulticide against Ae. albopictus and may be a useful tool for use in mosquito abatement programs.

A checklist of the mosquitoes of New Jersey with notes on established invasive species.

A checklist of 63 species of mosquitoes endemic in New Jersey is presented. Although Aedes albopictus was included in the previous checklist, the species has dramatically increased its geographic range and population numbers in recent years, and it is now prevalent in 19 of New Jersey's 21 counties. The invasive Aedes japonicus japonicus is also now widespread throughout the state and is an addition to the previous checklist. Culex erraticus, an endemic species with a previous distribution primarily in the southern portion of the state, has also expanded its range significantly in New Jersey in recent years and is now detected state-wide. Mosquito control personnel periodically discover localized populations of Ae. aegypti, but the species fails to overwinter successfully in New Jersey and is not included on the checklist.

A droplet collection device and support system for ultra-low-volume adulticide trials.

A supporting stand to suspend rotating impactors and mosquito cages is a requirement for field tests during pesticide efficacy trials. We present schematics for a collection device and associated support system for sampling droplets of ultra-low-volume (ULV) sprays during mosquito adulticide applications. This system offers the advantages of cost efficiency, increased ease of deployment, off-season storage, visibility, stability, and ULV collection efficacy. Use of this system ensures that droplet collection and meteorological equipment is at appropriate and consistent heights between trials. The 2 arms of the support allow for placement of multiple cages, light-emitting or reflecting devices, and wind-indicating ribbons to be attached to the station. The support described makes possible deployment of stations over a wider variety of terrains, increasing the extent of field trials. Presentation of the simple design and fabrication of the rotating collection device (impactor), T-station, and its support is provided.

An unusual larval collection and survival of Orthopodomyia signifera in the presence of the predator Toxorhynchites rutilus septentrionalis.

From a discarded heavy-equipment tire (ca. 57 liter) at an industrial construction site, we collected 655 (86.0%) Orthopodomyia signifera, 23 (3.0%) Toxorhynchites rutilus septentrionalis, 17 (2.2%) Aedes japonicus japonicus, and 67 (8.8%) Culex pipiens pipiens. Although larvae of Aedes albopictus and Aedes triseriatus were not collected from this container, both species were prevalent as host-seeking adults and readily collected as larvae from other containers at this site. Laboratory trials to test the survival of prey (Ae. albopictus, Cx. p. pipiens, or Or. signifera) in the presence of Tx. rut. septentrionalis showed that survival of prey larvae differed among species. Multiple comparisons revealed that Ae. albopictus had the lowest and Or. signifera the highest survival in the presence of Tx. rut. septentrionalis. Survival of Or. signifera and Cx. p. pipiens was not significantly different from one another, but both were different from Ae. albopictus. Further testing is warranted to test other factors responsible for differences in the interspecific relationship between Or. signifera and other species in tree hole communities.