Climate and vector potential of medically important North American ticks.

2021 ◽  
pp. 188-192
Author(s):  
Lars Eisen ◽  
Rebecca Eisen

Abstract This expert opinion focuses on climate-related factors and how these interact with landscape and tick host/pathogen reservoir factors to impact the vector potential for the three most notable North American human-biting tick species: Ixodes scapularis, Amblyomma americanum and the American dog tick, Dermacentor variabilis.

2004 ◽  
Vol 39 (3) ◽  
pp. 426-432 ◽  
Author(s):  
Alan B. Wells ◽  
Lance A. Durden ◽  
John H. Smoyer

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.


Author(s):  
E A Bacon ◽  
H Kopsco ◽  
P Gronemeyer ◽  
N Mateus-Pinilla ◽  
R L Smith

Abstract The range of ticks in North America has been steadily increasing likely, in part, due to climate change. Along with it, there has been a rise in cases of tick-borne disease. Among those medically important tick species of particular concern are Ixodes scapularis Say (Acari: Ixodidae), Dermacentor variabilis Say (Acari: Ixodidae), and Amblyomma americanum Linneaus (Acari: Ixodidae). The aim of this study was to determine if climate factors explain existing differences in abundance of the three aforementioned tick species between two climatically different regions of Illinois (Central and Southern), and if climate variables impact each species differently. We used both zero-inflated regression approaches and Bayesian network analyses to assess relationships among environmental variables and tick abundance. Results suggested that the maximum average temperature and total precipitation are associated with differential impact on species abundance and that this difference varied by region. Results also reinforced a differential level of resistance to desiccation among these tick species. Our findings help to further define risk periods of tick exposure for the general public, and reinforce the importance of responding to each tick species differently.


PLoS ONE ◽  
2021 ◽  
Vol 16 (11) ◽  
pp. e0259769
Author(s):  
Ram K. Raghavan ◽  
Zoe L. Koestel ◽  
Gunavanthi Boorgula ◽  
Ali Hroobi ◽  
Roman Ganta ◽  
...  

Unexpected questing activity of ticks was noted during the winter months of January and February in the Central Midwestern states of Kansas, Missouri, Oklahoma, and Arkansas. From nine geographically distinct locations, four species of ticks were collected using the flagging method, of which the lone star tick, Amblyomma americanum, was most abundant, followed by the American dog tick, Dermacentor variabilis, the Gulf coast tick, Amblyomma maculatum, and the Black legged tick, Ixodes scapularis. More A. americanum nymphs were caught questing than male or female adults. The winter activity of these medically important ticks in this region poses concern for public health and offers an insight into future tick activity in light of ongoing climate change. More studies on the seasonality of these tick species, and how different climate parameters affect their seasonal activity in this region are warranted and would be expected to benefit for both human and veterinary medicine.


Insects ◽  
2019 ◽  
Vol 10 (8) ◽  
pp. 235 ◽  
Author(s):  
Glass ◽  
Ganser ◽  
Wisely ◽  
Kessler

A statewide survey of questing ixodid ticks in mainland Florida was developed consistent with U.S. CDC standards to maximize the amount of epidemiologic and environmental data gathered. Survey sites were stratified by climatic zones and proportional to recognized land cover categories. A total of 560 transects on 41 sites within the state were sampled repeatedly by flagging between 2015 and 2018. Four tick species were collected; Amblyomma americanum, Amblyomma maculatum, Ixodes scapularis and Dermacentor variabilis. All species were more commonly found in northern and central regions of the state than in southern and western regions. Adult I. scapularis were active from autumn through spring and complementary to adult A. americanum and D. variabilis. Standardized survey methods help reduce sampling biases and better characterize risk from the species surveyed. However, differences in the attractiveness of collection methods for different tick species makes cross-species comparisons a continuing challenge.


Author(s):  
R A Butler ◽  
M L Kennedy ◽  
A E Houston ◽  
E K Bowers ◽  
L B Coons ◽  
...  

Abstract Investigations that analyze interspecific associations of vectors on their hosts are important for understanding community structure and implementing ways to comprehend mechanisms of pathogen transmission. We assessed the interspecific association of two tick species (Ixodes scapularis Say (Ixodida: Ixodidae) and Dermacentor variabilis Say (Ixodida: Ixodidae)) on the rodent host Peromyscus leucopus Rafinesque (Rodentia: Cricetidae) at the Hobart Ames Research and Education Center in southwestern Tennessee. Of the rodents captured, 95 (63%) had neither species of tick, 6 (4%) had both tick species, 25 (16%) had I. scapularis only, and 26 (17%) had D. variabilis only. A coefficient of association (C7 = −0.08) was calculated, which suggested there was competition between the two species of ectoparasites, but this value was not significant, indicating that there was a neutral relationship between the tick species on P. leucopus. The co-occurrence of both tick species on their host at the same time suggested that the two tick species can occupy the same host and use the same resources without competing.


Parasitologia ◽  
2021 ◽  
Vol 1 (3) ◽  
pp. 137-147
Author(s):  
Mark Spare ◽  
Gunavanthi D. Boorgula ◽  
Dan Thomson ◽  
Jianfa Bai ◽  
Doug Goodin ◽  
...  

Diversity and phenology of host-seeking ticks were studied in the Flint Hills region of the USA, which is a prominent region for raising beef cattle. Between a two-year period from 2015–2017, ticks were collected using the dragging method from 9 distant locations, 6 of which were studied seasonally and 3 continuously throughout the study period. Of the 10,055 ticks collected, 76.5% were the Lonestar tick (Amblyomma americanum), 14% were American dog tick (Dermacentor variabilis), and 9.1% were Gulf Coast tick (A. maculatum). The blacklegged tick, Ixodes scapularis were also found, albeit in low numbers. The host-seeking activity of all three predominant tick species peaked once during the late spring, summer months in the region. The phenology of all ticks was positively associated with accumulated temperature and photoperiod. Additionally, the Normalized Vegetation Difference Index (NDVI) was associated with A. americanum, and saturation deficit and relative humidity were negatively associated with D. variabilis and A. maculatum tick phenology, respectively. This finding is useful to predict the times during a year in which cattle are at higher risk for exposure to these ticks and associated pathogens.


Acarologia ◽  
2018 ◽  
Vol 58 (4) ◽  
pp. 989-994
Author(s):  
Dakota A. Shade

Ticks are important ectoparasites due to their ability to transmit harmful pathogens and their study is thus significant for medical and veterinary practices around the world. Fluorescence has been found in numerous biological organisms, including ticks. However, the overall function, evolutionary significance, and distribution of fluorescence in ticks are unknown. This study examined tick fluorescence in purchased, unfed adult Amblyomma americanum (Linnaeus), A. maculatum Koch, Dermacentor variabilis (Say), D. andersoni (Stiles), Ixodes scapularis Say, and Rhipicephalus sanguineus Latreille ticks. An Olympus SZX7 microscope and NightSea SFA system with ultraviolet (UV) and royal blue sets were used for observing tick morphology. Ticks were shown to have widespread fluorescence in all species observed. The results corroborated previous studies, but with the addition of more fluorescent structures. Tick fluorescence could potentially play roles in communication or predator avoidance. Studies on tick behavior in conjunction with fluorescence are now called for to elucidate potential roles.


PLoS ONE ◽  
2021 ◽  
Vol 16 (4) ◽  
pp. e0250272
Author(s):  
Ali Hroobi ◽  
Gunavanthi D. Boorgula ◽  
David Gordon ◽  
Jianfa Bai ◽  
Doug Goodin ◽  
...  

Between March 2014 and February 2017, host-seeking ticks were collected during the late spring and summer months seasonally, and as well as continually through all seasons from several sites in a periurban environment in Pittsburg, Kansas, located in the Central Midwestern United States. All three post-emergent life-stages of Amblyomma americanum, and the adults of three other ticks viz. Dermacentor variabilis, A. maculatum, and Ixodes scapularis were collected using the flagging method, and were taxonomically identified using morphological and molecular methods. A total of 15946 ticks were collected from these sites. A vast majority of the ticks collected over the three-year study period was A. americanum (79.01%). The three other species collected included D. variabilis (13.10%), A. maculatum (7.15%), and Ixodes scapularis (0.73%). More female ticks of each species were collected throughout the study period from all sites, and a unimodal activity period was noted for all four species. The diversity, composition, and phenology of these medically significant tick species are discussed.


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