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The most economically significant ectoparasites in the tropics and subtropics are ixodid ticks, especially Rhipicephalus annulatus and Rhipicephalus sanguineus. Years of extensive use of the readily available acaricides have resulted in widespread resistance development in these ticks, as well as negative environmental consequences. Benzyl alcohol (BA) has been frequently used to treat pediculosis and scabies, and it may be an effective alternative to commonly used acaricides. The main aim of the present study was to evaluate the acaricide activity of BA and its combination with the regularly used chemical acaricides against R. annulatus and R. sanguineus. Different concentrations of BA alone and in combination with deltamethrin, cypermethrin and chlorpyrifos were tested in vitro against adult and larvae of both tick species. The results showed that BA is toxic to R. annulatus and R. sanguineus larvae, with 100% larval mortality at concentrations of ≥50 mL/L, and LC50 and LC90 attained the concentrations of 19.8 and 33.8 mL/L for R. annulatus and 18.8 and 31.8 mL/L for R. sanguineus, respectively. Furthermore, BA in combination with deltamethrin, cypermethrin and chlorpyrifos exhibited synergistic factors of 2.48, 1.26 and 1.68 against R. annulatus larvae and 1.64, 11.1 and 1.14 against R. sanguineus larvae for deltamethrin + BA, cypermethrin + BA and chlorpyrifos + BA, respectively. BA induced 100% mortality in adult R. annulatus at concentrations of ≥250 mL/L with LC50 and LC90 reached the concentrations of 111 and 154 mL/L, respectively. Additionally, BA had ovicidal activity causing complete inhibition of larval hatching at 100 mL/L. The combination of BA with deltamethrin and cypermethrin increased acetylcholinesterase inhibition, whereas the combination of BA with chlorpyrifos decreased glutathione (GSH) activity and malondialdehyde levels. In the field application, the combination of BA 50 mL/L and deltamethrin (DBA) resulted in a significant reduction in the percentage of ticks by 30.9% 28 days post‐treatment when compared with groups treated with deltamethrin alone. In conclusion, BA causes mortality in laboratory and field studies alone and in combination with cypermethrin or deltamethrin. BA can be used for control of ticks of different life stages, that is, eggs and larvae, through application to the ground. [ABSTRACT FROM AUTHOR]

The current study was conducted to investigate the efficacy and stability of D‐limonene (DL) and its nanoemulsion (DLN) against pigeon feather lice (Columbicola columbae) and their mode of action. DL pure form and DLN were prepared and characterized freshly and after storage for 50 days. In vitro bioassay on live lice was conducted with different concentrations of DL, DLN, and deltamethrin (DM). The results revealed significant mortality rates in the DL‐, DLN‐, DM‐treated groups when compared with the control (p < 0.05). The scanning electron micrographs of lice treated with DL and DLN revealed collapsed bodies with destruction in the cuticle of the mouthparts and damaged antennae. The 50 days stored DLN showed stability in their effectiveness when compared with the freshly prepared formulation. DL and DLN caused significant inhibition (p ≤ 0.05) in acetylcholinesterase activity (AchE). Malondialdehyde level (MDA) was significantly increased while glutathione was significantly decreased in DL‐ and DLN‐treated lice. In conclusion, DL and DLN have significant lousicidal activities. DLN showed better stability than DL after storage for 50 days. In addition, the mode of action of DL may associate with its effect on the cuticle of the lice body, inhibition of AchE, and increasing oxidative stress in the treated lice. [ABSTRACT FROM AUTHOR]

In Egypt, scare literature explored the coprological examination of domestic camels. Therefore, a total of 626 fecal samples from domestic dromedaries, Camelus dromedarius, permitted to slaughtering in El-Warrak abattoir, Giza were taken. Coproparasitological investigations including sedimentation and floatation techniques, fecal culture and larval identification were done. The overall prevalence of parasitic infections was 41.53%. Fifteen species of helminth eggs/protozoan oocysts were recovered. The prevalence of helminths was 28.11% (176/626) and that of protozoa was 5.59% (35/626). Mixed infections were reported in 7.82% (49/626) of camels. The revealed trematode was Fasciola sp. (1.12%), tapeworms belonged to Anoplocephalids (5.27%), protozoan oocysts were Eimeria cameli, E. dromedarii, E. rajasthani (11.02% for all Eimeria spp.) and Buxtonella sp. (0.32%). The recovered nematodes belonged to Trichuris sp. (1.92%) and trichostrongyles (31.0%). Coproculture of the later revealed the presence of 8 species; Trichostrongylus axei, Tr. colubriformis, Chabertia ovina, Ostertagia ostertagi, Haemonchus sp., Oesophagostomum sp., Bunostomum sp. and Nematodirus sp. Morphometric characteristics of larvae were recorded. Age and seasonal variations revealed significant (P=0.05) differences among examined camels. Animals aged more than 5 years had the highest infections rate (45.96%; 199/433) and nematodes were the significantly (P=0.05) predominant. In winter, the highest prevalence (60.67%; 108/178) was recorded. Oppositely, sex had no significant differences. Due to the expected important role played by imported camels in transmitting various parasitic infections, veterinarians and parasitologists are extremely advised to apply further studies on the helminth fauna, particularly gastrointestinal nematodes, of both domestic and imported camels, by the use of traditional and molecular tools. [ABSTRACT FROM AUTHOR]