title: Photosensitizers in the fight against ticks: safranin as a novel photodynamic fluorescent acaricide to control the camel tick Hyalomma dromedarii (Ixodidae).
abstract: Ticks transmit more pathogen species than any other group of blood-feeding arthropods worldwide, affecting humans, livestock, and companion animals. Hyalomma dromedarii is the predominant tick species infesting camels, and its effective control is of pivotal importance. In this research, we compared the phytoefficacy of safranin (SF), a fluorescent dye applied as an acaricide for the first time, to that of tetramethrin (TM) against engorged females of H. dromedarii through in vitro immersion bioassays. Furthermore, the effect of SF exposure was evaluated on the reproductive potential of surviving tick females. Different concentrations of SF (0.03, 0.06, 0.3, 1, and 4 % w:v) and TM (0.03, 0.13, 0.5, 2, and 4 %) were prepared in distilled water and administered to engorged females of H. dromedarii. SF-treated ticks were illuminated with a light source for 30 min post-treatment (PT). Photophysical properties of SF were studied, and the relative efficacy of the used light source and sunlight was calculated. Results showed that the minimum least concentration that causes 100 % acaricidal effect was 4 % PT with SF and TM, for 8 and 48 h, respectively. LC50 values 8 and 24 h PT were 0.08, 0.03 and 0.78, 0.20 %, respectively. Comparing LC50 and LC90 2 h PT, SF was 33 and 22 times more potent than TM. LT50 of 4 % SF and TM were 0.80 and 2.17 h, respectively. Treatment with the lowest concentrations of SF and TM induced reduction of the number of ovipositing females, eggs per female, ticks laying viable eggs, and hatched eggs. Overall, our results highlighted that SF is highly effective if compared to TM, allowing use to candidate it for the development of novel and safer acaricides.
authors.affiliation: Department of Parasitology, Faculty of Veterinary Medicine, Benha University, Moshtohor, Toukh, 13736, Egypt.
authors.forename: Hanem
authors.initials: H
authors.lastname: Khater
authors.affiliation: Department of Physics, Faculty of Science, Benha University, Benha, 13111, Egypt.
authors.forename: Nabil
authors.initials: N
authors.lastname: Hendawy
authors.affiliation: Unit of Vector Control, Phytochemistry and Nanotechnology, Department of Zoology, Annamalai University, Annamalainagar, Tamil Nadu, 608002, India.
authors.forename: Marimuthu
authors.initials: M
authors.lastname: Govindarajan
authors.affiliation: Division of Entomology, Department of Zoology, School of Life Sciences, Bharathiar University, Coimbatore, Tamil Nadu, 641046, India.
authors.forename: Kadarkarai
authors.initials: K
authors.lastname: Murugan
authors.affiliation: Insect Behavior Group, Department of Agriculture, Food and Environment, University of Pisa, via del Borghetto 80, Pisa, 56124, Italy. g.benelli@sssup.it.|The BioRobotics Institute, Sant'Anna School of Advanced Studies, Viale Rinaldo Piaggio 34, Pontedera, 56025, Italy. g.benelli@sssup.it.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Benelli
mesh_terms: D056810:Acaricides / Q000008:administration & dosage* / Q000737:chemistry; D000818:Animals; D002162:Camelus / Q000469:parasitology*; D005260:Female; D026863:Ixodidae / Q000187:drug effects* / Q000254:growth & development / Q000502:physiology; D010058:Oviposition / Q000187:drug effects; D010619:Phenazines / Q000737:chemistry; D017319:Photosensitizing Agents / Q000008:administration & dosage* / Q000737:chemistry; D011722:Pyrethrins / Q000008:administration & dosage; D012098:Reproduction / Q000187:drug effects; D013984:Tick Infestations / Q000188:drug therapy / Q000469:parasitology / Q000662:veterinary*
chemical_list: D056810:Acaricides; D010619:Phenazines; D017319:Photosensitizing Agents; D011722:Pyrethrins; C009195:safranine T; C009424:tetramethrin
keywords: Africa; Arbovirus; Fluorescent material; Ixodidae; Ovicides; Reproductive potential; Tetramethrin; Tick-borne diseases