More Like this

1. Global divergence of the human follicle mite Demodex folliculorum : Persistent associations between host ancestry and mite lineages

   https://doi.org/10.1073/pnas.1512609112  

   Palopoli, Michael F. ; Fergus, Daniel J. ; Minot, Samuel ; Pei, Dorothy T. ; Simison, W. Brian ; Fernandez-Silva, Iria ; Thoemmes, Megan S. ; Dunn, Robert R. ; Trautwein, Michelle ( December 2015 , Proceedings of the National Academy of Sciences)
2. Chigger mite ( Eutrombicula alfreddugesi ) ectoparasitism does not contribute to sex differences in growth rate in eastern fence lizards ( Sceloporus undulatus )

   https://doi.org/10.1002/ece3.10590  

   Conrad, Hailey ; Pollock, Nicholas B. ; John‐Alder, Henry ( October 2023 , Ecology and Evolution)

   Allen Moore, University of (Ed.)

   Parasitism is nearly ubiquitous in animals and is frequently associated with fitness costs in host organisms, including reduced growth, foraging, and reproduction. In many species, males tend to be more heavily parasitized than females and thus may bear greater costs of parasitism.Sceloporus undulatusis a female‐larger, sexually size dimorphic lizard species that is heavily parasitized by chigger mites (Eutrombicula alfreddugesi). In particular, the intensity of mite parasitism is higher in male than in female juveniles during the period of time when sex differences in growth rate lead to the development of sexual size dimorphism (SSD). Sex‐biased differences in fitness costs of parasitism have been documented in other species. We investigated whether there are growth costs of mite ectoparasitism, at a time coinciding with sex differences in growth rate and the onset of SSD. If there are sex‐biased growth costs of parasitism, then this could suggest a contribution to the development of SSD inS. undulatus. We measured growth and mite loads in two cohorts of unmanipulated, field‐active yearlings by conducting descriptive mark‐recapture studies during the activity seasons of 2016 and 2019. Yearling males had consistently higher mid‐summer mite loads and consistently lower growth rates than females. However, we found that growth rate and body condition were independent of mite load in both sexes. Furthermore, growth ratesandmite loads were higher in 2019 than in 2016. Our findings suggest that juveniles ofS. undulatusare highly tolerant of chigger mites and that any costs imposed by mites may be at the expense of functions other than growth. We conclude that sex‐biased mite ectoparasitism does not contribute to sex differences in growth rate and, therefore, does not contribute to the development of SSD.

    

   more » « less
3. First data on water mite (Acari, Hydrachnidia) assemblages of Point Rosa Marsh, Harrison Township, Michigan, USA,and their use as environmental bioindicators of aquatic health

   https://doi.org/10.24349/2m5p-c5ku  

   Vasquez, Adrian A. ; Kabalan, Bana A. ; Miller, Carol J. ( September 2022 , Acarologia)

   Water mites are aquatic arachnids that have been used in Europe and Central America as bioindicators of ecological health in various freshwater ecosystems (including bogs). Water mites can be found in high densities in the Laurentian Great Lakes and adjacent habitats. Although they are abundant, water mites are generally not used in the assessment of aquatic habitats in the Great Lakes and are usually assigned to the “other” category in macroinvertebrate assessments. This is despite evidence of their utility as aquatic bioindicators. In the present study we consider water mites as bioindicators of the environmental health of Point Rosa marsh, a threatened marsh found on the US side of transboundary Lake St. Clair. The abundance of water mites in Point Rosa Marsh increased from 2017 to 2019 as lake water levels increased. Although increasing water levels in Lake St. Clair can be considered a negative event due to loss of irreplaceable coastal habitat by erosion with potential economic impacts, this present study indicates that water mite populations in Point Rosa Marsh increased during the same period (2017 to 2019). As a result of our study we: update the biodiversity of water mites from Lake St. Clair with new records compared to the last report from the lake over 45 years ago, first report on water mite assemblages at Point Rosa marsh at the Lake St. Clair Metropark on Lake St. Clair and the first demonstration of water mites used as bioindicators in the habitats of the Laurentian Great Lakes. 

   more » « less
4. Can supplementary pollen feeding reduce varroa mite and virus levels and improve honey bee colony survival?

   https://doi.org/10.1007/s10493-020-00562-7  

   DeGrandi-Hoffman, Gloria ; Corby-Harris, Vanessa ; Chen, Yanping ; Graham, Henry ; Chambers, Mona ; Watkins deJong, Emily ; Ziolkowski, Nicholas ; Kang, Yun ; Gage, Stephanie ; Deeter, Megan ; et al ( December 2020 , Experimental and Applied Acarology)

   Abstract Varroa destructor is an ectoparasitic mite of immature and adult honey bees that can transmit several single-stranded RNA viruses to its host. Varroa reproduce in brood cells, and mite populations increase as colonies produce brood in spring and summer. Mite numbers also can sharply rise, particularly in the fall, by the migration of varroa into hives on foragers. Colonies with high levels of varroa and viruses often die over the winter. Feeding colonies pollen might keep virus levels low and improve survival because of the positive effects of pollen on immunity and colony growth. We compared varroa and virus levels and overwinter survival in colonies with (fed) and without (unfed) supplemental pollen. We also measured the frequency of capturing foragers with mites (FWM) at colony entrances to determine its relationship to varroa and virus levels. Colonies fed supplemental pollen were larger than unfed colonies and survived longer. Varroa populations and levels of Deformed wing virus (DWV) rose throughout the season, and were similar between fed and unfed colonies. The growth of varroa populations was correlated with FWM in fed and unfed colonies, and significantly affected DWV levels. Increasing frequencies of FWM and the effects on varroa populations might reduce the positive influence of supplemental pollen on immune function. However, pollen feeding can stimulate colony growth and this can improve colony survival. 

   more » « less
5. Genome-Wide Association Study Reveals a Genomic Region Associated with Mite-Recruitment Phenotypes in the Domesticated Grapevine (Vitis vinifera)

   https://doi.org/10.3390/genes12071013  

   LaPlante, Erika R. ; Fleming, Margaret B. ; Migicovsky, Zoë ; Weber, Marjorie Gail ( July 2021 , Genes)

   null (Ed.)

   Indirect defenses are plant phenotypes that reduce damage by attracting natural enemies of plant pests and pathogens to leaves. Despite their economic and ecological importance, few studies have investigated the genetic underpinnings of indirect defense phenotypes. Here, we present a genome-wide association study of five phenotypes previously determined to increase populations of beneficial (fungivorous and predacious) mites on grape leaves (genus Vitis): leaf bristles, leaf hairs, and the size, density, and depth of leaf domatia. Using a common garden genetic panel of 399 V. vinifera cultivars, we tested for genetic associations of these phenotypes using previously obtained genotyping data from the Vitis9kSNP array. We found one single nucleotide polymorphism (SNP) significantly associated with domatia density. This SNP (Chr5:1160194) is near two genes of interest: Importin Alpha Isoform 1 (VIT_205s0077g01440), involved in downy mildew resistance, and GATA Transcription Factor 8 (VIT_205s0077g01450), involved in leaf shape development. Our findings are among the first to examine the genomic regions associated with ecologically important plant traits that facilitate interactions with beneficial mites, and suggest promising candidate genes for breeding and genetic editing to increase naturally occurring predator-based defenses in grapevines. 

   more » « less