The Influence of Prescribed Fire, Habitat, and Weather on Amblyomma americanum (Ixodida: Ixodidae) in West-Central Illinois, USA.

Mary Gilliam,Kenneth Mccravy,Will Rechkemmer,Seán Jenkins

doi:10.3390/insects9020036

Mary Gilliam, Kenneth Mccravy + Show 2 more

Open Access

https://doi.org/10.3390/insects9020036

Copy DOI

Abstract

The distribution of Amblyomma americanum (L.) is changing and reports of tick-borne disease transmitted by A. americanum are increasing in the USA. We used flagging to collect ticks, surveyed vegetation and collected weather data in 2015 and 2016. A. americanum dominated collections in both years (97%). Ticks did not differ among burn treatments; however, tick abundance differed between years among total, adult, and larval ticks. Habitat variables showed a weak negative correlation to total ticks in respect to: Shannon diversity index, percent bare ground, perennial cover, and coarse woody debris. Nymphal ticks showed a weak negative correlation to percent bare ground and fewer adults were collected in areas with more leaf litter and coarse woody debris. Conversely, we found larvae more often in areas with more total cover, biennials, vines, shrubs, and leaf litter, suggesting habitat is important for this life stage. We compared weather variables to tick presence and found, in 2015, temperature, precipitation, humidity, and sample period influenced tick collection and were life stage specific. In 2016, temperature, precipitation, humidity, wind, and sample period influenced tick collection and were also life stage specific. These results indicate that spring burns in an oak woodland do not reduce ticks; other variables such as habitat and weather are more influential on tick abundance or presence at different life stages.

Highlights

The blacklegged tick (Ixodes scapularis Say), lone star tick (Amblyomma americanum L.) and American dog tick (Dermacentor variabilis Say) are known to vector a variety of pathogens that cause illnesses in humans and animals [1,2,3,4]
A. americanum are not competent vectors of Lyme disease (Borrelia burgdorferi), the bacterium causing this disease has been previously found in these ticks [7,8,9]
Total A. americanum and all life stages collected did not differ among burn treatments, which suggests that the low intensity burning conducted at the site had a limited effect on the number of ticks collected

Summary

Introduction

The blacklegged tick (Ixodes scapularis Say), lone star tick (Amblyomma americanum L.) and American dog tick (Dermacentor variabilis Say) are known to vector a variety of pathogens that cause illnesses in humans and animals [1,2,3,4]. Lyme disease is the most common tick- borne illness in the USA [6]. A. americanum are not competent vectors of Lyme disease (Borrelia burgdorferi), the bacterium causing this disease has been previously found in these ticks [7,8,9]. In the USA, A. americanum is known to vector several pathogens including human monocytotropic ehrlichiosis (Ehrlichia chaffeensis), canine and human granulocytic ehrlichiosis (Ehrlichia ewingii), tularemia (Francisella tularensis), southern tick-associated rash illness (STARI). (Borrelia lonstari), and a new Phlebovirus, Heartland virus [10,11,12]. Of these diseases, canine and human granulocytic ehlichiosis, monocytotropic ehrlichiosis and tularemia have been reported in Illinois [13]

Objectives

Methods

Discussion

Conclusion