Acaricidal efficacy of Calotropis procera (Asclepiadaceae) and Taraxacum officinale (Asteraceae) against Rhipicephalus microplus from Mardan, Pakistan

Authors: KHAN, ADIL - Abdul Wali Khan University; NASREEN, NASREEN - Abdul Wali Khan University; NIAZ, SADAF - Abdul Wali Khan University; AYAZ, SULTAN - Abdul Wali Khan University; NAEEM, HUMA - University Of Veterinary And Animal Sciences; MUHAMMAD, IJAZ - Abdul Wali Khan University; SAID, FAZAL - Abdul Wali Khan University; MITCHELL, ROBERT - US Department Of Energy; Perez De Leon, Adalberto - Beto; SNEHIL, GUPTA - Non ARS Employee; KUMAR, SACHIN - Indian Veterinary Research Institute

Submitted to: Experimental and Applied Acarology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/23/2019
Publication Date: 7/31/2019
Citation: Khan, A., Nasreen, N.A., Niaz, S., Ayaz, S., Naeem, H., Muhammad, I., Said, F., Mitchell, R.D., Perez De Leon, A.A., Snehil, G., Kumar, S. 2019. Acaricidal efficacy of Calotropis procera (Asclepiadaceae) and Taraxacum officinale (Asteraceae) against Rhipicephalus microplus from Mardan, Pakistan. Experimental and Applied Acarology. 78(4):595-608. https://doi.org/10.1007/s10493-019-00406-z.
DOI: https://doi.org/10.1007/s10493-019-00406-z

Interpretive Summary: Medicinal plants contain substances that could be used in the field as a safer alternative to control ticks and prevent the transmission of tick-borne diseases. The southern cattle fever tick, Rhipicephalus microplus, is particularly detrimental to the livestock industry because of its blood-feeding habit and role as vector of the microbes causing bovine babesiosis and anaplasmosis. Plants commonly found in Pakistan include the apple of Sodom, Calotropis procera, and the common dandelion, Taraxacum officinale. These plants were evaluated in the laboratory for acaricidal activity against R. microplus larvae and adults from the Mardan district. Extracts from both plants were found to be effective in reducing the number of eggs laid by treated female ticks, and killing treated larvae. Future experiments will investigate if the acaricidal activity observed is due to specific components in the whole-plant extracts tested. This scientific information will inform decisions to conduct efficacy studies in Pakistan using livestock infested with R. microplus.

Technical Abstract: Medicinal plants are used by traditional folk healers, modern physicians, and veterinarians as an alternative to conventional drugs to treat a wide range of disorders including parasitic diseases. Some compounds from these plants have been shown to have acaricidal activity and repel arthropods. The cattle tick Rhipicephalus microplus is one of the most destructive pests to the livestock industry in tropical and subtropical parts of the world. The potential to develop herbal acaricides to control R. microplus infestations is critical in maintaining cattle herd productivity, reducing economic losses, and curtailing the overuse of synthetic chemical acaricides. Calotropis procera, the apple of Sodom, and Taraxacum officinale, the common dandelion, were evaluated for acaricidal activity against R. microplus larvae and adults in vitro. Both plant species tested are common indigenous species of Pakistan where R. microplus infestations are widespread across livestock species including cattle, sheep, and goats. Whole-plant extracts derived from C. procera and T. officinale significantly reduced the index of egg laying (P'<'0.01) and increased the percent inhibition of oviposition of adult female ticks at a concentration of 40 mg/mL when assessed by the adult immersion test (AIT). Calotropis procera and T. officinale treatments at the same concentration also resulted in larval mortality of 96.0%'±'0.57 and 96.7%'±'0.88, respectively, as measured using the larval packet test (LPT). An increasing range of extract concentrations was tested to determine the LD50 and LD90 for C. procera, 3.21 and 21.15 mg/mL, respectively, and T. officinale, 4.04 and 18.92 mg/mL, respectively. These results indicate that further studies are warranted to determine the relative contribution of individual phytochemicals from whole-plant extracts on acaricidal activity. This information will guide the design of further acaricidal efficacy tests using livestock infested with R. microplus.