The Lone Star tick, Amblyomma americanum, transmits several bacterial pathogens including species of Anaplasma and Ehrlichia. Amblyomma americanum also hosts a number of non-pathogenic bacterial endosymbionts. Recent studies of other arthropod and insect vectors have documented that commensal microflora can influence transmission of vector-borne pathogens; however, little is known about tick microbiomes and their possible influence on tick-borne diseases. Our objective was to compare bacterial communities associated with A. americanum, comparing Anaplasma/Ehrlichia -infected and uninfected ticks. Field-collected questing specimens (n = 50) were used in the analyses, of which 17 were identified as Anaplasma/Ehrlichia infected based on PCR amplification and sequencing of groEL genes. Bacterial communities from each specimen were characterized using Illumina sequencing of 16S rRNA gene amplicon libraries. There was a broad range in diversity between samples, with inverse Simpson’s Diversity indices ranging from 1.28–89.5. There were no statistical differences in the overall microbial community structure between PCR diagnosed Anaplasma/Ehrlichia-positive and negative ticks, but there were differences based on collection method (P < 0.05), collection site (P < 0.05), and sex (P < 0.1) suggesting that environmental factors may structure A. americanum microbiomes. Interestingly, there was not always agreement between Illumina sequencing and PCR diagnostics: Ehrlichia was identified in 16S rRNA gene libraries from three PCR-negative specimens; conversely, Ehrlichia was not found in libraries of six PCR-positive ticks. Illumina sequencing also helped identify co-infections, for example, one specimen had both Ehrlichia and Anaplasma. Other taxa of interest in these specimens included Coxiella, Borrelia, and Rickettsia. Identification of bacterial community differences between specimens of a single tick species from a single geographical site indicates that intra-species differences in microbiomes were not due solely to pathogen presence/absence, but may be also driven by vector life history factors, including environment, life stage, population structure, and host choice.

Anopheles gambiae sensu stricto (s.s.) is a primary vector of Plasmodium falciparum in sub-Saharan Africa. Although some physiological differences among molecular and chromosomal forms of this species have been demonstrated, the relative susceptibility to malaria parasite infection among them has not been unequivocally shown. The objective of this study was to investigate P. falciparum circumsporozoite protein infection (CSP) positivity among An. gambiae s.s. chromosomal and molecular forms.

Tick‐borne disease surveillance and research rely on resource‐effective methods for tick collection. This study compared the respective performances of several trapping methods in a mixed grassland–forest habitat in western T ennessee. To test for temporal differences in effectiveness, sites were sampled monthly ( A pril– A ugust 2013) using dry ice, dragging, flagging, sweep netting, carbon dioxide ( CO ₂ ) dragging and CO ₂ flagging methods. To evaluate the effect of habitat on method effectiveness, four methods (dragging, CO ₂ dragging, CO ₂ flagging and dry ice) were compared in four habitat types (bottomland deciduous, upland deciduous, coniferous and grassland) in J une 2014. In the temporal comparison, ticks were found to be most abundant in A pril and M ay, and there was a significant sampling period and method interaction, such that method effectiveness varied across sampling period. Sweep netting was significantly less effective than the other methods. In the habitat comparison, dry ice trap collections represented the most effective method in upland deciduous and coniferous habitats. Flagging using CO ₂ was significantly less effective than CO ₂ dragging and dragging in bottomland deciduous habitats. The success of the various collection methods did not differ significantly within grassland habitats. Overall, dry ice trapping and dragging were the most effective methods for tick collection across time and habitat.

Two tick-borne diseases with expanding case and vector distributions are ehrlichiosis (transmitted by Amblyomma americanum) and rickettiosis (transmitted by A. maculatum and Dermacentor variabilis). There is a critical need to identify the specific habitats where each of these species is likely to be encountered to classify and pinpoint risk areas. Consequently, an in-depth tick prevalence study was conducted on the dominant ticks in the southeast. Vegetation, soil, and remote sensing data were used to test the hypothesis that habitat and vegetation variables can predict tick abundances. No variables were significant predictors of A. americanum adult and nymph tick abundance, and no clustering was evident because this species was found throughout the study area. For A. maculatum adult tick abundance was predicted by NDVI and by the interaction between habitat type and plant diversity; two significant population clusters were identified in a heterogeneous area suitable for quail habitat. For D. variabilis no environmental variables were significant predictors of adult abundance; however, D. variabilis collections clustered in three significant areas best described as agriculture areas with defined edges. This study identified few landscape and vegetation variables associated with tick presence. While some variables were significantly associated with tick populations, the amount of explained variation was not useful for predicting reliably where ticks occur; consequently, additional research that includes multiple sampling seasons and locations throughout the southeast are warranted. This low amount of explained variation may also be due to the use of hosts for dispersal, and potentially to other abiotic and biotic variables. Host species play a large role in the establishment, maintenance, and dispersal of a tick species, as well as the maintenance of disease cycles, dispersal to new areas, and identification of risk areas.

Phytophthora capsici causes significant loss to pepper (Capsicum annum) in China and our goal was to develop single nucleotide polymorphism (SNP) markers for P. capsici and characterize genetic diversity nationwide. Eighteen isolates of P. capsici from locations worldwide were re-sequenced and candidate nuclear and mitochondrial SNPs identified. From 2006 to 2012, 276 isolates of P. capsici were recovered from 136 locations in 27 provinces and genotyped using 45 nuclear and 2 mitochondrial SNPs. There were two main mitochondrial haplotypes and 95 multi-locus genotypes (MLGs) identified. Genetic diversity was geographically structured with a high level of genotypic diversity in the north and on Hainan Island in the south, suggesting outcrossing contributes to diversity in these areas. The remaining areas of China are dominated by four clonal lineages that share mitochondrial haplotypes, are almost exclusively the A1 or A2 mating type and appear to exhibit extensive diversity based on loss of heterozygosity (LOH). Analysis of SNPs directly from infected peppers confirmed LOH in field populations. One clonal lineage is dominant throughout much of the country. The overall implications for long-lived genetically diverse clonal lineages amidst a widely dispersed sexual population are discussed.

Increased threat of mosquito-borne disease coupled with decreased tolerance of nuisance mosquitoes has opened a market for pest management professionals to offer mosquito control services for homeowners. A pest management professional applied bifenthrin (0.08%) and lambda-cyhalothrin (0.1%) at their maximum label concentrations as barrier treatments. We tested treatments residual efficacy in reducing adult mosquito populations and compared these chemicals against a water control at 24 residential properties (eight replications by three treatments). Mosquito populations were measured on each property by using five methods: CO2-baited Centers for Disease Control (CDC) light traps (without a light), human landing rates, CDC gravid traps, ovitraps, and sweep nets. Populations were monitored weekly for 2 wk before treatment and 8 wk posttreatment. Additionally, to confirm residual efficacy of each insecticide, a randomly treated leaf underwent a no-choice bioassay with laboratory-reared Aedes albopictus (Skuse). Trap collections were dominantly Aedes albopictus and Culex pipiens L. Both insecticidal treatments significantly reduced Aedes spp. lambda-Cyhalothrin- and bifenthrin-treated sites had 89.5 and 85.1% fewer Ae. albopictus bites than the untreated control, respectively. Ae. albopictus bioassay results showed significant residual efficacy for both insecticides up to 6 wk posttreatment. There were no significant differences between properties treated with the two insecticides. In contrast, Culex spp. were not reduced by either insecticidal treatment. Our study indicated that barrier sprays applied to low-lying vegetation do not properly target adult daytime resting sites for Culex mosquitoes but that they can reduce Aedes mosquitoes. Perhaps by treating upper tree canopies Culex spp. abundance may be reduced.