Feeding and respiratory gas exchange of Rhipicephalus sanguineus sensu lato (Acari: ixodidae)

Authors: LANDULFO, GABRIEL - Federal University Of Maranhão; Li, Andrew; LIMA, ALDILENE - Federal University Of Maranhão; SILVA, NAYLENE C. - Federal University Of Maranhão; VALE, TASSIA - Federal University Of Maranhão; COSTA-JUNIOR, LIVIO - Federal University Of Maranhão

Submitted to: Experimental and Applied Acarology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/28/2019
Publication Date: 5/30/2019
Citation: Landulfo, G.A., Li, A.Y., Lima, A.S., Silva, N.S., Vale, T.L., Costa-Junior, L.M. 2019. Feeding and respiratory gas exchange of Rhipicephalus sanguineus sensu lato (Acari: ixodidae). Experimental and Applied Acarology. https://doi.org/10.1007/s10493-019-00383-3.
DOI: https://doi.org/10.1007/s10493-019-00383-3

Interpretive Summary: Ticks and tick-borne diseases have increasing impacts on public health and the wellbeing of domestic animals and wildlife. The brown dog tick has a worldwide distribution. This tick species mainly feeds on dogs, but can also bite humans and other animals. The brown dog tick transmits pathogens than can cause several serious diseases in dogs, such as canine ehrlichiosis and canine babesia. It is also known that brown dog ticks can Rocky Mountain spotted fever to humans. It is essential to understand the biology and physiology of ticks in order to develop the next-generation tick control technologies (pesticides, repellents) for tick control. USDA ARS scientists joined force with researchers in Brazil through a collaborative effort to study tick respiratory physiology with an aim to identify new control target in tick's physiological systems. The study revealed dramatically enhanced gas exchange or respiration rate after blood feeding. This may lead to new exploratory researches for new pesticide development. The results obtained from this study are of interest to tick biologists and researchers who work in the field of tick control and new pesticide development.

Technical Abstract: Ticks are subject to various environmental constrains, such as dehydration, desiccation and long-waiting for hosts to attach. These factors are crucial for tick survival in the environment. Ticks have developed physiological mechanisms and/or strategies that allow adaptability and survival in the environment in which they live, such as spiracle control and cyclical or discontinuous gas exchanges. However, details of gas exchange profile have been reported only in a few tick species in the past. The present study aims to identify and describe respiratory gas exchange patterns in a tropical population of the brown dog tick Rhipicephalus sanguineus sensu lato and effects of blood feeding. Adult female ticks were fed on rabbit hosts. Partially fed (4 to 6 days) and completely fed (> 9 days) were collected at daily during feeding, weighed and subjected to CO2 emission measurement at 25°C using flow-through respirometry. Unfed adult females showed a well-defined periodical burst of CO2 emissions, followed by short periods of low-emission intercepts. The fed groups had drastic changes in respiratory profiles with semi-engorged females showing a high intensity respiratory pattern alternating between continuous and discontinuous and the engorged females showing a continuous respiratory pattern with high frequency and intensity. The findings from this study contribute to a better understanding of the respiratory physiological process of a tropical population of the dog tick, which may help future investigations on other biological aspects of this ectoparasite and development of control measures.