scholarly journals Modeling the Distribution of Medically Important Tick Species in Florida

Insects ◽  
2019 ◽  
Vol 10 (7) ◽  
pp. 190 ◽  
Author(s):  
William H. Kessler ◽  
Claudia Ganser ◽  
Gregory E. Glass
Keyword(s):  
Habitat Suitability ◽  
Vegetation Index ◽  
Normalized Difference Vegetation Index ◽  
Ixodes Scapularis ◽  
Dermacentor Variabilis ◽  
Amblyomma Americanum ◽  
Suitable Habitat ◽  
Public Health Importance ◽  
Raising Awareness ◽  
Great Public Health

The lone star (Amblyomma americanum), black-legged (Ixodes scapularis) and American dog ticks (Dermacentor variabilis) are species of great public health importance as they are competent vectors of several notable pathogens. While the regional distributions of these species are well characterized, more localized distribution estimates are sparse. We used records of field collected ticks and an ensemble modeling approach to predict habitat suitability for each of these species in Florida. Environmental variables capturing climatic extremes were common contributors to habitat suitability. Most frequently, annual precipitation (Bio12), mean temperature of the driest quarter (Bio9), minimum temperature of the coldest month (Bio6), and mean Normalized Difference Vegetation Index (NDVI) were included in the final models for each species. Agreement between the modeling algorithms used in this study was high and indicated the distribution of suitable habitat for all three species was reduced at lower latitudes. These findings are important for raising awareness of the potential for tick-borne pathogens in Florida.

Landscape-scale habitat associations of small mammals on the western coast of Hudson Bay

2021 ◽  
Author(s):  
Kevin Hawkshaw ◽  
Lee Foote ◽  
Alastair Franke
Keyword(s):  
Small Mammals ◽  
Vegetation Index ◽  
Normalized Difference Vegetation Index ◽  
Distance Sampling ◽  
Habitat Associations ◽  
Ground Squirrels ◽  
Suitable Habitat ◽  
Western Coast ◽  
Water Index ◽  
Arctic Ground Squirrels

Availability of suitable habitat affects the distribution and abundance of Arctic fauna, influencing how species respond to climate change and disturbance from resource extraction in the region. We surveyed Arctic ground squirrels (Urocitellus parryii Richardson, 1825) using distance sampling transects and concurrently counted microtine rodent burrows. Abundance of Arctic ground squirrels and microtine burrows was positively correlated with terrain ruggedness. Microtine burrows were more abundant inland and in areas with freshwater, while Arctic ground squirrels were more often found at low elevation without freshwater. Arctic ground squirrel abundance was positively related to the normalized difference water index, a proxy for vegetation water content, while microtine burrows were weakly correlated with the normalized difference vegetation index. Our study highlights the habitat associations of ecologically significant small mammals in an underrepresented Arctic study area.

scholarly journals Towards improved, cost-effective surveillance of Ixodes ricinus ticks and associated pathogens using species distribution modelling

2019 ◽  
Vol 14 (1) ◽  
Author(s):  
Manuela Signorini ◽  
Anna-Sofie Stensgaard ◽  
Michele Drigo ◽  
Giulia Simonato ◽  
Federica Marcer ◽  
...  
Keyword(s):  
Ixodes Ricinus ◽  
Habitat Suitability ◽  
Pathogen Detection ◽  
Vegetation Index ◽  
Normalized Difference Vegetation Index ◽  
Cost Effective ◽  
Limiting Factor ◽  
Sampling Effort ◽  
Remotely Sensed Data ◽  
Ecological Requirements

Various ticks exist in the temperate hilly and pre-alpine areas of Northern Italy, where Ixodes ricinus is the more important. In this area different tick-borne pathogen monitoring projects have recently been implemented; we present here the results of a twoyear field survey of ticks and associated pathogens, conducted 2009-2010 in North-eastern Italy. The cost-effectiveness of different sampling strategies, hypothesized a posteriori based on two sub-sets of data, were compared and analysed. The same two subsets were also used to develop models of habitat suitability, using a maximum entropy algorithm based on remotely sensed data. Comparison of the two strategies (in terms of number of ticks collected, rates of pathogen detection and model accuracy) indicated that monitoring at many temporary sites was more cost-effective than monthly samplings at a few permanent sites. The two model predictions were similar and provided a greater understanding of ecological requirements of I. ricinus in the study area. Dense vegetation cover, as measured by the normalized difference vegetation index, was identified as a good predictor of tick presence, whereas high summer temperatures appeared to be a limiting factor. The study suggests that it is possible to obtain realistic results (in terms of pathogens detection and development of habitat suitability maps) with a relatively limited sampling effort and a wellplanned monitoring strategy.

Low Abundance of Three Tick Species in the Piedmont of North Carolina

2020 ◽  
Author(s):  
Madeline P Seagle ◽  
Maximilian R Vierling ◽  
Ryan J Almeida ◽  
D Jacob Clary ◽  
Will Hidell ◽  
...  
Keyword(s):  
North Carolina ◽  
Ixodes Scapularis ◽  
Dermacentor Variabilis ◽  
Amblyomma Americanum ◽  
Host Factors ◽  
Southeast United States ◽  
The North ◽  
Mecklenburg County ◽  
North Carolina Piedmont ◽  
Multiple Species

Abstract Multiple species of ticks, including Ixodes scapularis (Say, Ixodida:Ixodidae), Amblyomma americanum (L., Ixodida:Ixodidae), and Dermacentor variabilis (Say, Ixodida:Ixodidae), occur in high and increasing abundance in both the northeast and southeast United States. North Carolina is at the nexus of spread of these species, with high occurrence and abundance of I. scapularis to the north and A. americanum to the south. Despite this, there are few records of these species in the Piedmont of North Carolina, including the greater Charlotte metropolitan area. Here, we update the known occurrence and abundance of these species in the North Carolina Piedmont. We surveyed for ticks using cloth drags, CO2 traps, and leaf litter samples at a total of 79 sites within five locations: Mecklenburg County, South Mountains State Park, Stone Mountain State Park, Duke Forest, and Morrow Mountain State Park, all in North Carolina, during the late spring, summer, and fall seasons of 2019. From these surveys, we had only 20 tick captures, illuminating the surprisingly low abundance of ticks in this region of North Carolina. Our results indicate the possibility of underlying habitat and host factors limiting tick distribution and abundance in the North Carolina Piedmont.

Ticks (Acari: Ixodidae) Parasitizing Domestic Dogs in Southeastern Georgia

2004 ◽  
Vol 39 (3) ◽  
pp. 426-432 ◽  
Author(s):  
Alan B. Wells ◽  
Lance A. Durden ◽  
John H. Smoyer
Keyword(s):  
Gulf Coast ◽  
Ixodes Scapularis ◽  
Rhipicephalus Sanguineus ◽  
Dermacentor Variabilis ◽  
Amblyomma Americanum ◽  
Domestic Dogs ◽  
Gopher Tortoise ◽  
Gulf Coast Tick ◽  
Dog Tick ◽  
Ixodes Affinis

Ticks (Acari: Ixodidae) were collected from family-owned domestic dogs, Canis familiaris L., in Bulloch Co., GA, from 1996 to 2003 and from dogs maintained in a shelter in Emanuel Co., GA, in 2002 and 2003. A total of 2,466 ticks representing 9 species was recovered. The most frequently recovered species from family-owned dogs were the blacklegged tick, Ixodes scapularis Say (54.6% of all ticks from this group of dogs), and American dog tick, Dermacentor variabilis (Say) (27.7%). Collections from shelter-maintained dogs were dominated by the brown dog tick, Rhipicephalus sanguineus (Latreille) (73.6%). Except for 39 nymphs of the lone star tick, Amblyomma americanum (L.), 12 nymphs of R. sanguineus, 7 nymphs of the Gulf Coast tick, Amblyomma maculatum Koch, 1 nymph of D. variabilis and 72 larvae of the gopher tortoise tick, Amblyomma tuberculatum Marx, only adult ticks were present. Seasonally, I. scapularis adults were recorded from October through May and were most common in the fall; whereas, A. americanum, A. maculatum, A. tuberculatum, D. variabilis, and Ixodes affinis Neumann were all found only during the spring, summer and/or early fall. Two species of ticks collected during this study, A. tuberculatum and I. affinis, have Coastal Plain distributions in the southern U.S. and would only be expected to parasitize dogs within this region.

scholarly journals Identification of Novel Viruses in Amblyomma americanum , Dermacentor variabilis , and Ixodes scapularis Ticks

mSphere ◽  
2018 ◽  
Vol 3 (2) ◽  
Author(s):  
Rafal Tokarz ◽  
Stephen Sameroff ◽  
Teresa Tagliafierro ◽  
Komal Jain ◽  
Simon H. Williams ◽  
...  
Keyword(s):  
New York ◽  
High Throughput ◽  
High Throughput Sequencing ◽  
Ixodes Scapularis ◽  
The United States ◽  
Dermacentor Variabilis ◽  
Amblyomma Americanum ◽  
Animal Pathogens ◽  
Wide Range ◽  
Sequencing Platforms

ABSTRACT Ticks carry a wide range of known human and animal pathogens and are postulated to carry others with the potential to cause disease. Here we report a discovery effort wherein unbiased high-throughput sequencing was used to characterize the virome of 2,021 ticks, including Ixodes scapularis ( n = 1,138), Amblyomma americanum ( n = 720), and Dermacentor variabilis ( n = 163), collected in New York, Connecticut, and Virginia in 2015 and 2016. We identified 33 viruses, including 24 putative novel viral species. The most frequently detected viruses were phylogenetically related to members of the Bunyaviridae and Rhabdoviridae families, as well as the recently proposed Chuviridae . Our work expands our understanding of tick viromes and underscores the high viral diversity that is present in ticks. IMPORTANCE The incidence of tick-borne disease is increasing, driven by rapid geographical expansion of ticks and the discovery of new tick-associated pathogens. The examination of the tick microbiome is essential in order to understand the relationship between microbes and their tick hosts and to facilitate the identification of new tick-borne pathogens. Genomic analyses using unbiased high-throughput sequencing platforms have proven valuable for investigations of tick bacterial diversity, but the examination of tick viromes has historically not been well explored. By performing a comprehensive virome analysis of the three primary tick species associated with human disease in the United States, we gained substantial insight into tick virome diversity and can begin to assess a potential role of these viruses in the tick life cycle.

scholarly journals Identification of public submitted tick images: A neural network approach

PLoS ONE ◽  
2021 ◽  
Vol 16 (12) ◽  
pp. e0260622
Author(s):  
Lennart Justen ◽  
Duncan Carlsmith ◽  
Susan M. Paskewitz ◽  
Lyric C. Bartholomay ◽  
Gebbiena M. Bron
Keyword(s):  
Public Health ◽  
Neural Network ◽  
Deep Learning ◽  
Ixodes Scapularis ◽  
Dermacentor Variabilis ◽  
Amblyomma Americanum ◽  
Identification Accuracy ◽  
Small Object ◽  
Neural Network Approach ◽  
Public Health Agencies

Ticks and tick-borne diseases represent a growing public health threat in North America and Europe. The number of ticks, their geographical distribution, and the incidence of tick-borne diseases, like Lyme disease, are all on the rise. Accurate, real-time tick-image identification through a smartphone app or similar platform could help mitigate this threat by informing users of the risks associated with encountered ticks and by providing researchers and public health agencies with additional data on tick activity and geographic range. Here we outline the requirements for such a system, present a model that meets those requirements, and discuss remaining challenges and frontiers in automated tick identification. We compiled a user-generated dataset of more than 12,000 images of the three most common tick species found on humans in the U.S.: Amblyomma americanum, Dermacentor variabilis, and Ixodes scapularis. We used image augmentation to further increase the size of our dataset to more than 90,000 images. Here we report the development and validation of a convolutional neural network which we call “TickIDNet,” that scores an 87.8% identification accuracy across all three species, outperforming the accuracy of identifications done by a member of the general public or healthcare professionals. However, the model fails to match the performance of experts with formal entomological training. We find that image quality, particularly the size of the tick in the image (measured in pixels), plays a significant role in the network’s ability to correctly identify an image: images where the tick is small are less likely to be correctly identified because of the small object detection problem in deep learning. TickIDNet’s performance can be increased by using confidence thresholds to introduce an “unsure” class and building image submission pipelines that encourage better quality photos. Our findings suggest that deep learning represents a promising frontier for tick identification that should be further explored and deployed as part of the toolkit for addressing the public health consequences of tick-borne diseases.

scholarly journals Equine attachment site preferences and seasonality of common North American ticks: Amblyomma americanum, Dermacentor albipictus, and Ixodes scapularis

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Kellee D. Sundstrom ◽  
Megan W. Lineberry ◽  
Amber N. Grant ◽  
Kathryn T. Duncan ◽  
Michelle M. Ientile ◽  
...  
Keyword(s):  
North America ◽  
Tick Infestation ◽  
Ixodes Scapularis ◽  
Attachment Site ◽  
Dermacentor Variabilis ◽  
Amblyomma Americanum ◽  
Site Preferences ◽  
Dermacentor Albipictus ◽  
Attachment Sites ◽  
Axillary Region

Abstract Background Ticks are common on horses, but recent publications characterizing equine tick infestations in North America are lacking. Methods To further understand attachment site preferences of common ticks of horses, and to document the seasonality of equine tick infestation in northeastern Oklahoma, horses from eight farms were evaluated twice a month over a 1-year period. Each horse was systematically inspected beginning at the head and moving caudally to the tail. Attachment sites of ticks were recorded and all ticks collected were identified to species and stage. Results Horses (26 males and 62 females) enrolled in the study ranged in age from 1 to 23 years (mean = 12, 95% CI 11–13). A total of 2731 ticks were collected; 84.1% (74/88) of the horses were infested (median = 3 ticks) at one or more examinations. Five tick species were identified, including Amblyomma americanum (78.2%; 2136/2731), Ixodes scapularis (18.2%; 497/2731), Dermacentor albipictus brown variant (2.6%; 71/2731), Dermacentor variabilis (0.7%; 20/2731), and Amblyomma maculatum (0.3%; 7/231). Most ticks were adults (83.6%; 2282/2731), but immature A. americanum (436/2136; 20.4%), D. albipictus (12/71; 16.9%), and A. maculatum (n = 1) were occasionally recovered. Amblyomma americanum were most often attached to the inguinal area, and I. scapularis and D. albipictus were most commonly found on the chest and axillary region (P < 0.0001). Ticks were found on horses in every month of the year. The largest number of ticks (638/2731; 23.4%) were collected in May (P < 0.0001). Amblyomma americanum, primarily immature, was the only tick recovered in September, I. scapularis and D. albipictus predominated October through February, and both A. americanum and I. scapularis were common in March. In the warmer months, April through August, A. americanum was the most common tick, followed by D. variabilis and A. maculatum. Conclusions This research confirms that ticks common on horses in North America have attachment site preferences and that ticks infest horses in Oklahoma throughout the year, including during the winter. Additional research is warranted to fully understand the risk these infestations pose to equine health. Graphical abstract

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