Daily Variation in Sampled Densities of Ixodes scapularis and Amblyomma americanum (Acari: Ixodidae) Nymphs at a Single Site—Implications for Assessing Acarological Risk

2022 ◽  
Author(s):  
Terry L Schulze ◽  
Robert A Jordan
Keyword(s):  
Ixodes Scapularis ◽  
Spatial Scales ◽  
Amblyomma Americanum ◽  
Full Description ◽  
Spatial And Temporal Variability ◽  
Sampling Effort ◽  
Protection Measures ◽  
Host Seeking ◽  
Sampling Protocols ◽  
Temporal And Spatial

Abstract The public health challenge posed by tick-borne disease (TBD) has increased efforts to characterize the spatial and temporal distribution of ticks and associated pathogens to better focus tick control strategies and personal protection measures. We describe variability in nymphal Ixodes scapularis Say and Amblyomma americanum (L.) density derived from daily drag sampling at a single location in New Jersey over 4 yr and explore how observed differences in daily collections might affect the estimation of acarological risk. We found significant variability in the density of host-seeking nymphs that could suggest substantially different rates of human-tick encounters depending on sampling date, habitat, and ambient weather conditions. The spatial and temporal variability in the distribution of 2 sympatric tick species with different host preferences and questing strategies, suggests that to produce results that are comparable among sites across the area sampled, surveillance efforts may be limited to shorter collection seasons, fewer sites or less sampling effort (fewer plots or fewer visits) per site, and a geographic scope that minimizes the potential temporal and spatial biases indicated here. Our results illustrate that evaluation of models of tick distribution or relative acarological risk based on surveillance data requires a full description of the diversity of habitats sampled and the conditions under which sampling is performed. The array of factors that affect tick host-seeking and that could bias interpretation of sampling results emphasizes the need to standardize sampling protocols and for more caution when interpreting tick sampling data collected over large temporal and spatial scales.

Synthetic Pyrethroid, Natural Product, and Entomopathogenic Fungal Acaricide Product Formulations for Sustained Early Season Suppression of Host-Seeking Ixodes scapularis (Acari: Ixodidae) and Amblyomma americanum Nymphs

2020 ◽  
Author(s):  
Terry L Schulze ◽  
Robert A Jordan
Keyword(s):  
Natural Product ◽  
Ixodes Scapularis ◽  
Tick Control ◽  
Amblyomma Americanum ◽  
Synthetic Pyrethroid ◽  
Activity Period ◽  
Synthetic Pyrethroids ◽  
Seasonal Activity ◽  
Early Season ◽  
Host Seeking

Abstract We compared the ability of product formulations representing a synthetic pyrethroid acaricide (Talstar P Professional Insecticide), a natural product-based acaricide (Essentria IC3), and an entomopathogenic fungal acaricide (Met52 EC Bioinsecticide) to suppress Ixodes scapularis Say and Amblyomma americanum (L.) nymphs when applied following USEPA approved manufacturers’ label recommendations for tick control using hand-pumped knapsack sprayers before the beginning of their seasonal activity period in the spring. We applied Met52 EC Bioinsecticide (11% Metarhizium anisopliae Strain F52) to five 100 m2 plots (10.6 ml AI/plot) in mid-April 2020. Two weeks later at the end of April 2020, we treated an additional five 100 m2 plots each with either Talstar P Professional Insecticide (7.9% bifenthrin @ 2.5 ml AI/plot) or Essentria IC3 (10% rosemary oil, 5% geraniol, and 2% peppermint oil @ 86.6 ml AI/plot). Weekly sampling of all plots through the end of June 2020 showed that both Met52 EC Bioinsecticide and Essentria IC3 failed to maintain a 90% suppression threshold for I. scapularis, compared to control plots, and required two additional applications over the course of the trial. In contrast, Talstar P Professional Insecticide suppressed 100% of I. scapularis nymphs and ≥96 and 100% of A. americanum nymphs and adults, respectively. Such pre-season applications of synthetic pyrethroids significantly reduce the early season acarological risk for exposure to host-seeking ticks as well as the frequency of acaricide applications.

The value of a broad temporal and spatial perspective in understanding dynamics of kelp forest ecosystems

2016 ◽  
Vol 67 (1) ◽  
pp. 14 ◽  
Author(s):  
Daniel C. Reed ◽  
Andrew R. Rassweiler ◽  
Robert J. Miller ◽  
Henry M. Page ◽  
Sally J. Holbrook
Keyword(s):  
Forest Ecosystems ◽  
Spatial Scales ◽  
Kelp Forest ◽  
Small Scale ◽  
Spatial And Temporal Variability ◽  
Short Term ◽  
Spatial Perspective ◽  
Ecological Responses ◽  
Temporal And Spatial

Many ecological processes play out over longer time scales and larger spatial scales than can be studied in a traditional 2–4-year grant cycle. Uncertainties in future funding hinder efforts to implement comprehensive research programs that integrate coupled time series observations of physical variables and ecological responses, manipulative experiments and synthetic analyses over the long term. Such research is essential for advancing our understanding of ecological responses associated with climate change, and the physical and biological processes that control them. This need is perhaps greatest for ecosystems that display highly dynamic and spatially complex patterns that are difficult to explain with short-term, small-scale studies. Such is the case for kelp forest ecosystems, which often show tremendous spatial and temporal variability in resource supply, consumer control and physical disturbance across spatial scales of metres to hundreds of kilometres and temporal scales of hours to decades. Here we present four examples from the Santa Barbara Coastal Long-term Ecological Research project that demonstrate the value of a broad temporal and spatial perspective in understanding the causes and ecological consequences of short-term local dynamics of giant kelp forests of California, USA.

Optimising occupancy models and detection probability for conservation monitoring in a forest-dwelling small mammal

2019 ◽  
Author(s):  
Fraser John Combe ◽  
Jonathan S Ellis ◽  
Simone Bullion ◽  
Paul Chanin ◽  
Phillip C Wheater ◽  
...  
Keyword(s):  
Small Mammal ◽  
Detection Probability ◽  
Spatial Scales ◽  
Spatial And Temporal Variation ◽  
Sampling Effort ◽  
Occupancy Models ◽  
Effective Population ◽  
Temporal And Spatial ◽  
Elusive Species ◽  
Hazel Dormouse

The ability to determine the survey effort required to detect species presence is critical for the conservation of populations in order to monitor changes in distribution or abundance, a challenge for rare and elusive species. While designing an effective population survey may be of concern to scientists, it may also be a legal requirement for protected species. We analysed how spatial and temporal variation in sampling effort impacts detection probability in the hazel dormouse (Muscardinus avellanarius), a small mammal that naturally occurs at low density in forest habitat. We used presence and absence data from 144 sites in England, UK. We found that detection probability was strongly affected by survey intensity, with a 37.5% increase in detection probability when sampling effort was increased from 16 to 50 nest tubes per site. We also show that detection probability is highly temporally dependent; monitoring early in the year results in low detection probability (21%-53%; April-June), whilst detection dramatically increased later in the year (89%; September). Our results suggest that variation in detection probability can be complex and influenced by effects at temporal and spatial scales, and by sampling effort. We show that sampling effort can be minimised depending on seasonal variation in detection probability, however this is likely to be species and method dependent.

scholarly journals Artificial Accumulation of Leaf Litter in Forest Edges on Residential Properties via Leaf Blowing Is Associated with Increased Numbers of Host-Seeking Ixodes scapularis (Acari: Ixodidae) Nymphs

2020 ◽  
Vol 57 (4) ◽  
pp. 1193-1198
Author(s):  
Robert A Jordan ◽  
Terry L Schulze
Keyword(s):  
Leaf Litter ◽  
Ixodes Scapularis ◽  
Forest Edge ◽  
Amblyomma Americanum ◽  
Forest Edges ◽  
Host Seeking ◽  
Frequent Use ◽  
Residential Properties ◽  
Unmanaged Forest ◽  
Yard Maintenance

Abstract We examined whether routine fall yard maintenance, specifically depositing leaves removed from lawns and landscaping along forest margins, may increase densities of nymphal Ixodes scapularis Say and Amblyomma americanum (L.) ticks within these managed areas. Leaf blowing activities in fall 2017 and 2018 on residential properties in New Jersey, United States, significantly increased leaf litter depth in managed edge areas (range = 259.8–352.8 mm) compared to unmanaged edges (77.6–188.0 mm) and adjacent forest (39.4–166.2 mm). Drag sampling conducted on 20 and 30 dates in spring 2018 and 2019, respectively, yielded ≥3-fold more I. scapularis nymphs in managed edge plots compared to natural edge and forest plots in both years. In 2018, we collected more A. americanum nymphs from forest plots than from either natural or managed edge plots, but 2019 natural edge plots yielded the greatest number of the ticks. Nearly half of A. americanum adults were collected in forest plots in both years. Our data suggest that the acarological risk of human encounters with I. scapularis nymphs may be significantly greater in areas receiving an accumulation of leaves from leaf blowing or raking compared to adjacent unmanaged forest edges. This artificially elevated acarological risk can be mitigated if homeowners avail themselves of curbside leaf pickup or composting services offered by many municipalities or request that lawn/landscaping contractors remove collected leaves offsite, or at least to areas of less frequent use, rather than concentrating them along the lawn-forest edge.

Early Season Applications of Bifenthrin Suppress Host-seeking Ixodes scapularis and Amblyomma americanum (Acari: Ixodidae) Nymphs

2019 ◽  
Vol 57 (3) ◽  
pp. 797-800 ◽  
Author(s):  
Terry L Schulze ◽  
Robert A Jordan
Keyword(s):  
Active Treatment ◽  
Ixodes Scapularis ◽  
Amblyomma Americanum ◽  
Activity Period ◽  
Peak Activity ◽  
Early Season ◽  
Host Seeking ◽  
Application Date ◽  
Risk Of Exposure ◽  
And Control

Abstract We assessed the efficacy of bifenthrin to suppress Ixodes scapularis Say and Amblyomma americanum (L.) nymphs when applied prior to the initiation of spring host-seeking activity versus when nymphs were already active. Treatment and control plots were sampled for host-seeking ticks every week from mid-April through June, and single occasion bifenthrin applications were done in different sets of treatment plots on 15 April, 29 April, 13 May, and 27 May. Ixodes scapularis nymphs and A. americanum nymphs and adults were effectively suppressed after each application, with at or near 100% suppression of all ticks being observed for up to 8-wk postapplication. Irrespective of the bifenthrin application date, the level of suppression of I. scapularis nymphs never declined below 70% during the study period. However, with the exception of the last application, the suppression of A. americanum nymphs decreased dramatically to below 25% by the conclusion of the trial. The results of this study demonstrated that preseason applications of bifenthrin can mitigate acarological risk of exposure to ticks throughout much of their spring peak activity period.

scholarly journals Surveillance of Host-Seeking Ticks in the Flint Hills Region (USA) and Associations with Environmental Determinants

Parasitologia ◽  
2021 ◽  
Vol 1 (3) ◽  
pp. 137-147
Author(s):  
Mark Spare ◽  
Gunavanthi D. Boorgula ◽  
Dan Thomson ◽  
Jianfa Bai ◽  
Doug Goodin ◽  
...  
Keyword(s):  
Gulf Coast ◽  
Ixodes Scapularis ◽  
Dermacentor Variabilis ◽  
Amblyomma Americanum ◽  
Flint Hills ◽  
Host Seeking ◽  
The Usa ◽  
Gulf Coast Tick ◽  
The Times ◽  
Dog Tick

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.

scholarly journals Diversity and seasonality of host-seeking ticks in a periurban environment in the Central Midwest (USA)

PLoS ONE ◽  
2021 ◽  
Vol 16 (4) ◽  
pp. e0250272
Author(s):  
Ali Hroobi ◽  
Gunavanthi D. Boorgula ◽  
David Gordon ◽  
Jianfa Bai ◽  
Doug Goodin ◽  
...  
Keyword(s):  
United States ◽  
Tick Species ◽  
Ixodes Scapularis ◽  
Dermacentor Variabilis ◽  
Amblyomma Americanum ◽  
Late Spring ◽  
Molecular Methods ◽  
Activity Period ◽  
Life Stages ◽  
Host Seeking

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.

scholarly journals Detecting Long Time Changes in Benthic Macroalgal Cover Using Landsat Image Archive

2020 ◽  
Vol 12 (11) ◽  
pp. 1901 ◽  
Author(s):  
Laura Lõugas ◽  
Tiit Kutser ◽  
Jonne Kotta ◽  
Ele Vahtmäe
Keyword(s):  
Spatial Scales ◽  
Landsat Imagery ◽  
Spatial And Temporal Variability ◽  
Sampling Effort ◽  
Algal Communities ◽  
Macroalgal Cover ◽  
Long Time ◽  
Time Changes ◽  
Biased Estimates

Coastal macroalgae worldwide provide multiple ecological functions and support vital ecosystem services. Thereby, it is important to monitor changes in the extent of benthic macroalgal cover. However, as in situ sampling is costly and time-consuming, areal estimates of macroalgal species cover are often based only on a limited number of samples. This low sampling effort likely yields very biased estimates, as macroalgal communities are often characterized by large spatial variability at multiple spatial scales. Moreover, ecological time series are often short-term, making it impossible to assess changes in algal communities over decades and relate this to different human pressures and/or climate change. The Landsat series satellites have operated for 40 years. In the current study, we tested if the Landsat sensors could be used for mapping the cover of shallow water benthic macroalgae. This study was carried out at two sites in the West Estonian Archipelago, in the northeastern Baltic Sea. Our results show that the Landsat imagery accurately reflected both spatial and temporal variability in benthic algal cover. To conclude, the current methodology can be used to improve the existing assessments of areal macroalgal cover, or to estimate the cover values, in areas and times lacking ecological observations.

Patterns in habitat and fish assemblages within Great Lakes coastal wetlands and implications for sampling design

2009 ◽  
Vol 66 (8) ◽  
pp. 1343-1354 ◽  
Author(s):  
Anett S. Trebitz ◽  
John C. Brazner ◽  
Mark S. Pearson ◽  
Gregory S. Peterson ◽  
Danny K. Tanner ◽  
...  
Keyword(s):  
Great Lakes ◽  
Vegetation Structure ◽  
Coastal Wetlands ◽  
Fish Assemblages ◽  
Spatial Scales ◽  
Habitat Associations ◽  
Sampling Effort ◽  
Barrier Beach ◽  
Sampling Protocols ◽  
Great Lakes Coastal Wetlands

Discerning fish–habitat associations at a variety of spatial scales is relevant to evaluating biotic conditions and stressor responses in Great Lakes coastal wetlands. Ordination analyses identified strong, geographically organized associations among anthropogenic stressors and water clarity, vegetation structure, and fish composition at both whole-wetland and within-wetland spatial scales. Lacustrine-protected wetlands were generally internally homogeneous in fish composition, whereas riverine or barrier-beach lagoon wetlands could be more heterogeneous, especially if they had large tributaries and complex morphology or if the mouth area was more directly exposed to the adjacent lake than were other areas. A tendency towards more turbidity-tolerant fish but fewer vegetation spawners, nest guarders, or game and panfish differentiated both more-disturbed from less-disturbed wetlands and open-water from vegetated areas within wetlands. Variation in vegetation structure related to wetland hydromorphology and anthropogenic impacts makes standardizing fish sampling protocols by microhabitat impractical across broad spatial or disturbance gradients. We recommend distributing sampling effort across available microhabitats and show that both fish and habitat can be adequately characterized with a single field day of effort.

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