Assessing the effects of the leaf and seed ethanolic extracts of carica papaya against the brown dog tick (Rhipicephalus sanguineus)

• Main Authors: Del Rosario, Alexandra Ysabel H., Carmelina, Danica Marie S.D., Marciano, Ma. Czarina Angela E., Yau, Trixie B.
• Format: text
• Language: English
• Published: Animo Repository 2024
• Subjects: Papaya—Therapeutic use; Plant extracts—Therapeutic use; Brown dog tick; Biology
• Online Access: https://animorepository.dlsu.edu.ph/etdb_bio/69
• Institution: De La Salle University

Previous research have covered the acaricidal activities of Carica papaya extract on a number of tick species under the Rhipicephalus genus, but none so far have extensively evaluated its effects on Rhipicephalus sanguineus ticks. The tick species R. sanguineus is the most prevalent tick species in the Philippines, and serves as a common vector to several tick-borne pathogens. Despite the implementation of commercially-available chemical acaricides, repeated usage of these has often resulted in undesirable second-hand effects that concern the environment, health, and the growing resistance of ticks. This study aimed to investigate the acaricidal activity towards this particular tick species by utilizing papaya leaf and seed ethanolic extracts. In order to do so, an adult immersion test (AIT), adult acaricidal activity test (AAAT), and larval packet test (LPT) were performed. Based on the results of the AIT for engorged and semi-engorged R. sanguineus ticks, no significant demonstration of mortality, reproductive index (RI), and inhibition of oviposition (IO) was detectable. Conversely though, results for non-engorged R. sanguineus ticks under the AAAT, and larvae under the LPT yielded considerable results. The results of the AAAT showed significant mortality rates for 100 mg/ml concentrations of both papaya leaf (88.9%) and papaya seed (100%) ethanolic extracts. Similarly, the LPT determined that treatments applied at 100 mg/ml for both papaya leaf (97.0%) and papaya seed (90.0%) ethanolic extract induced significant mortality as well. The study overall showed the significance of the treatments in varying degrees in terms of concentration and life stages. It also appeared that papaya leaf and seed ultimately demonstrate similar acaricidal effects, with there being no significant differences between the two as determined by the measured parameters. Keywords: Carica papaya, acaricidal activity, ethanolic extracts, Rhipicephalus sanguineus, brown dog tick, adult immersion test (AIT), adult acaricidal activity test (AAAT), and larval packet test (LPT), mortality rates, reproductive index (RI) and inhibition of oviposition (IO).