Focus Stacking Images of Morphological Character States for Differentiating the Adults of Ixodes affinis and Ixodes scapularis (Acari: Ixodidae) in Areas of Sympatry

Adult females and males of Ixodes affinis and Ixodes scapularis are illustrated by focus stacking image photography, and morphological character states are described that reliably differentiate the two species. In conjunction with other environmental cues, such as the questing phenology of adults, these characteristics will enable the rapid identification of adults of either sex along the southern Coastal Plain of the United States, where these species are sympatric.

A Comparison of Tick Collection Materials and Methods in Southeastern Virginia

In field studies of tick ecology, observed patterns may be biased by sampling methods. Results can vary by species, life stage, and habitat, and understanding these biases will improve comparisons of data across studies as well as assessment of human disease risk. A direct comparison of flagging versus dragging was conducted in southeastern Virginia. Transects were surveyed over a 6-wk period to identify differences in species and life stage collected, as well as differences between corduroy and denim material and inspection method for drags. Flagging collected more Ixodes affinis Neumann (Acari: Ixodidae) adults and Amblyomma americanum L. (Acari: Ixodidae) adults than dragging. Ground inspection was more efficient than tree inspection for collection of I. affinis adults, with no significant difference in inspection method for any other species or life stage. Corduroy was found to be more effective than denim in collecting nymphal A. americanum, although this may be an artifact of three large samples for corduroy collection of these ticks. There was no significant difference in Ixodes scapularis Say (Acari: Ixodidae) collection in any comparison. Dragging, tree inspection, and denim were not found to be more efficient in any scenario. This is the first comparison of flagging and dragging conducted in the southeastern United States. The community composition of ticks in this region greatly differs from regions where studies of these commonly used sampling techniques have been conducted. As the distributions of ticks continue to change over time, it will be important to evaluate best practices annually.

Rickettsia spp. en garrapatas (Acari: Ixodidae) infestando perros de una comunidad rural con antecedentes de rickettsiosis, Yucatán, México

Introducción. Las bacterias del género Rickettsia son agentes causales de las rickettsiosis, enfermedades zoonóticas endémicas en México. En Yucatán, ocurrió un brote en habitantes de Bolmay; sin embargo, no se identificó el probable artrópodo transmisor. Objetivo. Reportar la presencia de Rickettsia spp. en garrapatas infestando perros domésticos de Bolmay.Material y métodos. Se trabajaron 105 viales con hasta ocho garrapatas. Se extrajo ADN de los ectoparásitos, posterior a la identificación del ciclo de desarrollo vital, la diferenciación sexual, género y especie. Se realizaron dos PCR para aislar fragmentos de los genes htrA (17-kDa) y rOmpB, pertenecientes a Rickettsia spp. Los productos positivos fueron secuenciados y analizados con la herramienta BLAST y el algoritmo Megablast. Resultados. Se utilizaron 291 garrapatas de los géneros Amblyomma (55.7%, 162/291), Rhipicephalus (34%, 99/291) e Ixodes (10.3%, 30/291), y las especies: Rhipicephalus sanguineus sensu lato, Ixodes affinis, Amblyomma cajennense y Amblyomma ovale. La positividad por PCR fue de 11.4% (12/105) para los géneros Amblyomma (66.7%, 8/12), Rhipicephalus (25%, 3/12) e Ixodes (8.3%, 1/12), y las especies A. cajennense, Rh. sanguineus s. l. e I. affinis. Se identificó ADN rickettsial en ninfas, larvas y adultos, y en machos y hembras. El análisis BLAST arrojó un 99% de cobertura e identidad con secuencias de Rickettsia spp.Conclusión. Los géneros y algunas especies de garrapatas infestando perros de Bolmay, probablemente están involucrados en el ciclo de transmisión de Rickettsia spp. a los habitantes. Se presenta la primera evidencia molecular de Rickettsia spp. en garrapatas I. affinis de Yucatán, México.