LB 19-172 - Integrating biotic and abiotic factors to identify climatically suitable and infestation-prone areas for the tick Rhipicephalus (Boophilus) microplus in the Americas

Thursday, August 10, 2023

5:00 PM – 6:30 PM PDT

Location: ESA Exhibit Hall

Presenting Author(s)

Laura Jimenez, Universidad de Chile

Posdoctoral researcher
Centro de Modelamiento Matemático
Santiago, Region Metropolitana, Chile

Coauthor(s)

RM

Roberta Marques, Benemérita Universidad Autónoma de Puebla

Posdoctoral researcher
Centro de Agroecologia y Ambiente
Puebla, Puebla, Mexico
DJ

Daniel Jimenez-Garcia, Benemérita Universidad Autónoma de Puebla

Associate professor
Centro de Agroecologia y Ambiente
Puebla, Puebla, Mexico

The tick Rhipicephalus (Boophilus) microplus is a hematophagous ectoparasite of both domestic and wild animals which may transmit anaplasmosis or babesiosis (cattle fever), two diseases that have a significant impact on hosts' health. For example, babesiosis causes weight loss and, in extreme cases, the death of infected cattle, generating substantial economic losses. Therefore, identifying regions that are at risk of infestation is an essential task for the prevention of livestock losses and the management of wild host species. The goal of this study was to identify areas prone to tick infestation in the Americas. For this, we first estimated the fundamental Grinnelian niche of R. (B). microplus using a Bayesian model that combines two types of data: presence data from open-access databases, and physiological tolerance ranges experimentally obtained in previous studies. To fit the model, we only used presence data that included metadata on the life stage of the recorded individual. We split these data into two groups: adults and individuals in life stages previous to adulthood, and fitted three models using different combinations of these two sets to determine if the species' environmental requirements change for adults and non-adult ticks. Then, we used presence data of some confirmed wild host species of R. (B). microplus to identify areas with high host density that may foster the presence of tick populations (which increases disease transmission). Finally, we proposed a method to include host density in the niche modeling of R. (B.) microplus and used it to identify areas at risk of infestation.The fundamental niche model fitted with the presence data of individuals in life stages previous to adulthood was smaller than the one obtained for the presence data of adults. By combining information on abiotic (fundamental niche) and biotic factors (host density), we characterized the realized niche of R. (B.) microplus. We showed that sites with a high concentration of potential hosts are part of the realized niche of the species, even though the environmental conditions at these sites have low suitability or lie outside its fundamental niche. By identifying sites belonging to the species' realized niche, we located areas with favorable climatic conditions and appropriate biotic interactions that may be at higher risk of infestation. In the Americas, the regions identified as prone to tick infestation were Eastern United States, central Colombia, southern Mexico, Guatemala, Southern Brazil, and Uruguay.