Acaricidal Drugs Research Articles

Impact of Farm Management Practices on Tick Infestation in Punjab's Livestock: A Comprehensive Epidemiological Study.

Tick infestation poses an important challenge to livestock in Pakistan. Farm management practices and environmental variables can influence tick infestation prevalence in animals. To this end, a cross-sectional survey of 96 farms in four different geographical districts (24 farms from each district) was conducted in Punjab, Pakistan, between October 2021 and January 2022. An epidemiological questionnaire was designed focusing on farm management practices and their impact on tick infestations at these farms. Data were collected via in-person interviews. Regional and farm-specific variables' associations were evaluated using Pearson's chi-square test and Fischer's exact test, respectively. A multivariable logistic regression model was used to identify significant risk factors. This study identified that using soft bedding materials, e.g., wheat straw, leaf litter or plain soil posed a significant risk of tick infestation. Additionally, the absence of quarantine measures, open sheds and inadequate drainage were found as contributing factors in univariable analysis. Higher tick prevalence in the hotter seasons highlighted the influence of Punjab's extreme weather on tick infestation. Despite regular veterinary visits and the use of acaricidal drugs, the prevalence of tick infestation at these farms suggested potential drug resistance in the ticks. The study recommended establishing quarantine practices, improving farms' drainage systems and bedding and using a combination of chemical and traditional remedies to tackle drug resistance in ticks. Education and awareness programs on tick-borne diseases and control measures are advocated to reduce the tick infestation burden on animals. Further research on longitudinal studies to better understand tick population dynamics and develop effective acaricides is encouraged. This called for collaborative control efforts among farmers, veterinarians and research institutions.

The effectiveness of acaricidal drugs in bovine psoroptosis

The report presents the results of acaricides using from the macrocyclic lactones group and complex drug administration which includes deltamethrin, diflubenzuron and piperonyl butoxide by psoroptic scab of cattle. There was research at the beefproducing farm (Aberdeen Angus breed). It was four groups (n=10 by each). Animals of the 1st experimental group have received «Meradoc» drug (doramectin 1%, subcutaneous introduction, the neck area), 2d experimental group – «Ivermec» drug (ivermectin 1%, 1 ml per 50 kg, subcutaneous introduction, the neck area), 3d experimental group – «Deltsid 7.5» by single dose (15 ml per 100 kg) by the application on skin vertebral from the head to the tail. The 4th group was control without acaricidal treatment. It was found the single using of macrocyclic lactones groups’ drugs were destroyed only the larval, nymphal and imaginal phases of acarian Psoroptes without ticks’ eggs extermination. The scraping was included ticks’ eggs on 7th day after «Deltsid 7.5» drug using, but it wasn’t detected any larval, imaginal phases and ticks’ eggs on the 14th, 21st and 28th days after beginning of animal’s treatment. Moreover, to the 28th days there were registered the hair restoration and the skin in affected areas without compaction and folding. The using of complex drug «Deltsid 7.5» is more effective treatment of psoroptic scab of cattle. This drug has the acaricidal effect on the preimaginal phases Acariformes. There were blocked the enzymes activity which destroy the drug’s effect. To take on the Acariformes resistibility by acaricides it should be control the quality of anti-acaricidal treatments by microscopy of skin scrapings. The recommendation in the case of the positive result’s getting is the treatment alternation.

Efficacy of hydroethanolic extract of Randia aculeata seed against the southern cattle tick Rhipicephalus (Boophilus) microplus (Acari: Ixodidae) on naturally infested cattle under field conditions.

The cattle tick Rhipicephalus (Boophilus) microplus is a major problem of concern for cattle industry in tropical and subtropical areas. Control of cattle tick is based mainly on the use of chemical acaricides, which has contributed to the emerging problem of selection of resistant tick lineages. Plants have been used as an alternative to conventional acaricidal drugs. On the other hand, the acaricidal activity of hydroethanolic extract of Randia aculeata seed (EHRA) has been demonstrated against R. microplus under laboratory conditions. However, the utility of EHRA seed as a potential acaricidal needs to be determined under field conditions. For this reason, the aim of this study was to evaluate the efficacy of the EHRA against R. microplus sprayed on naturally infested calves, determine the effect of theEHRA seedon acetylcholinesterase activity in R. microplus larval and identify the chemical composition of EHRA. Forty-five male calves were divided in three groups and treated with: G1 water; G2 EHRA 20% w/v and G3 coumaphos 0.2% v/v. Acetylcholinesterase (AChE) activity in R. microplus larvae was determined by a colorimetric assay. The chemical composition of EHRA was accessed through HPLC/MS. Significantly fewer ticks were observed after 24h on the treated group compared to control group. EHRA significantly inhibitedin vitroAChE activity inR.microplus at all tested concentrations. Chlorogenic acid, vanillinic acid, p-coumaric acid, caffeic acid. rutin, quercetin, (-)-epicatechin, 4-hydroxybenzoic acid, quercetin, vanillin, 2,4-dimethoxy-6-methylbenzoic acid, scopoletin and ferulic acid were identified in the extract. The results provided new data for the elucidation of the mechanisms of EHRA acaricide action and to further evaluate the use as a new alternative control agent againstR. microplus under in vivo conditions.

Successful long-term control of poultry red mite (Dermanyssus gallinae) infestations in floor-kept laying hens via integrated pest management—a case report

This case report describes the successful control of poultry red mite [PRM] (Dermanyssus gallinae) infestations in an experimental laying hen house via a combined use of cleaning and disinfection measure, the preventive application of a synthetic silica-based acaricide and frequent mite monitoring. The high number of PRM in the laying hen house was reduced by 99.8% by treatment with fluralaner (Exzolt®, MSD Animal Health Unterschleißheim, Germany; 0.5 mg/kg body weight via drinking water twice, 7 days apart). After the laying hens were removed, the hen house was dry-cleaned, wet-cleaned and disinfected. After drying, synthetic amorphous silica (Fossil Shield® instant white, Bein GmbH, Eiterfeld, Germany) was applied as a preventive measure before the hen house was restocked with pullets for two housing periods of 58 and 52 weeks. Over these periods (i.e. more than 2 years), no PRM was detected during mite monitoring at two-week intervals via tube traps and visual monitoring. This result therefore suggests that the combined use of appropriate chemical and physical prevention measures within an integrated pest management regime can be successfully used for the long-term control of PRM. This could reduce the use of acaricidal drugs, thereby helping maintain their efficacy.

Application of quantitative proteomics to discover biomarkers for tick resistance in cattle.

Breeding for tick resistance is a sustainable alternative to control cattle ticks due to widespread resistance to acaricidal drugs and the lack of a protective vaccine. The most accurate method used to characterise the phenotype for tick resistance in field studies is the standard tick count, but this is labour-intensive and can be hazardous to the operator. Efficient genetic selection requires reliable phenotyping or biomarker(s) for accurately identifying tick-resistant cattle. Although breed-specific genes associated with tick resistance have been identified, the mechanisms behind tick resistance have not yet been fully characterised. This study applied quantitative proteomics to examine the differential abundance of serum and skin proteins using samples from naïve tick-resistant and -susceptible Brangus cattle at two-time points following tick exposure. The proteins were digested into peptides, followed by identification and quantification using sequential window acquisition of all theoretical fragment ion mass spectrometry. Resistant naïve cattle had a suite of proteins associated with immune response, blood coagulation and wound healing that were significantly (adjusted P < 10- 5) more abundant compared with susceptible naïve cattle. These proteins included complement factors (C3, C4, C4a), alpha-1-acid glycoprotein (AGP), beta-2-glycoprotein-1, keratins (KRT1 & KRT3) and fibrinogens (alpha & beta). The mass spectrometry findings were validated by identifying differences in the relative abundance of selected serum proteins with ELISA. The proteins showing a significantly different abundance in resistant cattle following early and prolonged tick exposures (compared to resistant naïve) were associated with immune response, blood coagulation, homeostasis, and wound healing. In contrast, susceptible cattle developed some of these responses only after prolonged tick exposure. Resistant cattle were able to transmigrate immune-response related proteins towards the tick bite sites, which may prevent tick feeding. Significantly differentially abundant proteins identified in this research in resistant naïve cattle may provide a rapid and efficient protective response to tick infestation. Physical barrier (skin integrity and wound healing) mechanisms and systemic immune responses were key contributors to resistance. Immune response-related proteins such as C4, C4a, AGP and CGN1 (naïve samples), CD14, GC and AGP (post-infestation) should be further investigated as potential biomarkers for tick resistance.

First Description of Acaricide Resistance in Populations of Rhipicephalus microplus Tick from the Lower Amazon, Brazil.

There is limited information on the resistance to acaricidal drugs of the cattle tick Rhipicephalus microplus in the Lower Amazon region. Thus, we aimed to determine the efficiency of three widely used acaricide products (Amitraz, Cypermethrin, and Deltamethrin) in the control of this tick species. The adult immersion test was used on engorged female ticks sampled on farms in the Lower Amazon region, Brazil. For the test, homogeneous batches of 10 engorged females were placed in Petri dishes and immersed in the tested acaricidal drugs, using four replicates of each acaricide and three replicates as a negative control, immersed in distilled water. The acaricides were diluted as recommended by the manufacturers, and the ticks were submerged for five minutes. Mortality of engorged females, production of eggs, and percentage of larval hatching were evaluated. Tick mortality was 2.5%, 7.5%, and 0% for Amitraz, Cypermethrin, and Deltamethrin, respectively. The percentage of larval hatching was 53.7% for Amitraz, 88.7% for Cypermethrin, and 80.0% for Deltamethrin. As recommended by the FAO, for the acaricide to be considered effective, it must have a control rate ≥95%. Among the tested acaricides, Amitraz showed an efficacy of 90.5%, Cypermethrin 10.4%, and Deltamethrin 26.6%. Ticks from the lower Amazon showed marked resistance to Cypermethrin and Deltamethrin and mild resistance to Amitraz. This is the first report of acaricidal resistance in the region.

Therapeutic efficacy of the drug Simparica® for demodicosis in dogs in the Kamianets-Podilskyi, Ukraine

The purpose of our research was to test the therapeutic efficacy of the acaricide «Simparica®» in combination with the biostimulator «Catosal» and the hepatoprotector «Tioprotectin» for demodicosis in dogs in the conditions of veterinary clinics in the Kamianets-Podilskyi, Ukraine. The study has been performed on dogs of different genders, ages and breeds that had a generalized form of demodicosis (affected at least 6 areas on the body of animals), to test the effectiveness of this drug in different treatment schemes. Acarological studies of scrapings from the skin of experimental animals for the presence of live or dead mites Demodex canis or their eggs have been carried out by the vital method according to D.O. Pryselkova. As a result of the conducted researches the choice of acaricidal drugs and development of complex therapeutic measures for demodicosis of dogs has been experimentally substantiated. The drug «Simparica®» has proved to be quite effective against demodicosis of dogs, even with a single use. The dependence of the effectiveness of the use of prolonged acaricide «Simparica®» on clinical forms of demodicosis has been shown. The absolute therapeutic effect of acaricide is obtained in the scaly form of demodicosis. However, in pustular and mixed clinical forms of demodicosis, its effectiveness decreased to 71.4 and 57.1%, respectively. In combination with the drug of pathogenetic therapy «Catosal» for pustular and mixed forms of demodicosis, the therapeutic efficacy of the drug «Simparica®» increases to 85.7%. When added to the scheme of hepatoprotector “Thioprotectin”, it is possible to achieve 100% therapeutic effect in pustular forms of demodicosis. However, in severe mixed form of demodicosis, the effectiveness was not absolute and was only 85.7%. In case of generalized demodicosis of dogs, regardless of clinical forms, it is recommended to use the acaricide «Simparica®» in combination with the drug «Catosal» and in the combination of «Catosal» and «Thioprotectin».

Pharmacotherapy of knemidocoptosis in budgerigars

The article presents a study of the pharmacotherapeutic efficacy of drugs of etiotropic action Ivermikol drops and Aversectin ointment for cnemidocoptosis in budgerigars. Treatment was directed to the study of etiotropic therapy of acaricidal drugs in relation to the causative agents of invasion in sick birds and in the environment. Extensibility and intensity (EE and IE) of the drugs were assessed on the 6th, 22nd and 36th days after the treatment. A study group of budgies suffering from knemidocoptosis was given the following treatment regimen: ivermicol drops, chlorhexidine and Perlen multivitamized grain mixture for food. According to the treatment, on the 6th day in budgies, the extensibility was 0 %. On the 22nd day of treatment in 4 parrots during microscopic examination of scrapings from the affected areas, Knemidocoptes mites were found. Thus, the extensibility of ivermicol drops was 33.3 %. On the 36th day, the extensibility of the treatment of parrots with ivermicol drops was 100 %. Thus, the results obtained make it possible to recommend the indicated scheme for the treatment of ornamental birds for knemidocoptosis. Thuse of the treatment of sick budgerigars according to a different scheme (aversectin ointment, chlorhexidine and multivitamized Perlen grain mixture for nutrition) also proved to be effective. However, on the 22nd day of treatment, microscopic examination of scrapings from the affected areas revealed Knemidokoptes mites in 5 parrots, thus, the extensibility of aversectin ointment was 16.7 %. On the 36th day of treatment in parrots of the control group, which were treated with aversectin ointment, the EE of treatment was 66 %, since 2 out of 6 parrots remained sick, which required further treatment. The dynamics of the EE and IE of ivermicol drops and avesectin ointments on the 6th, 22nd, and 36th days of the study indicate the highest therapeutic efficacy of ivermicol drops. Thus, the use of ivermicol drops as a means of etiotropic action in the cinemidocoptosis of budgerigars is effective. Key words: scabies, treatment, knemidocoptosis, parrots, Cnemidocoptes pilae, acaricidalpreparations, ivermicoldrops, aversectinointment.

Study on Prevalence of Ixodid Ticks of Goats and Acaricide Utilization Practices of Herd Owners in Benatsemay District, South Omo Zone, South-Western Ethiopia.

IntroductionTicks are major health problems of goats that contribute to a significant economic loss in Ethiopia.MethodsA cross-sectional study using a systematic random sampling technique was conducted to determine the prevalence, potential risk factors of hard ticks (Acarina: Ixodidae) of goats, and the acaricide utilization practice of herd owners in the Benatsemay district.ResultsOut of 285 examined goats, 85.26% of goats were found infested by Rhipicephalus and Amblyomma tick genera. The body condition score of goats was the only factor that was significantly (p < 0.05) associated with tick infestations. The frequently identified tick species were Rhipicephalus pulchellus (14.38%), Rh. decoloratus (11.22%), A. cohaerens (5.26%) and A. variegatum (4.21%), and mixed infestation (38.59%). Herd owner’s questionnaire survey revealed that 100% of interviewees responded that tick infestations were frequently encountered throughout the year and prevailed on aged goats (90%) and dry season (60%). Concurrent usage of ethnomedicinal plants and conventional acaricides were dominant practices to control tick infestation as responded by 60% of interviewees. Among the conventional acaricides, Diazinon and Ivermectin were the most practiced acaricides as replied by 90% of the respondents. Moreover, community animal health workers (CAHWs) (43.33%) and owners themselves (33.33%) were primarily responsible for acaricide application to tick-infested animals. About 66.67% of the livestock owner’s responses also disclosed that diazinon was the most effective acaricide followed by ivermectin (16.67%) and amitraz (6.67%). Finally, 56.57% of the respondents replied that acaricidal drugs from private veterinary drug shops were overpriced than the same acaricides from government veterinary clinics.ConclusionIn this study, there was a high prevalence of hard ticks in goats, and irrational application of acaricides was noted in the Benatsemay district; thus, appropriate tick control measures should be taken to minimize tick burden through using acaricides.

Acaricidal activity of the hexanic and hydroethanolic extracts of three medicinal plants against southern cattle tick Rhipicephalus (Boophilus) microplus (Acari: Ixodidae).

The southern cattle tick Rhipicephalus microplus is a major problem for the cattle industry in tropical and subtropical areas worldwide. Chemical products are commonly applied to control it; however, their indiscriminate use has resulted in the appearance of resistant lineages. In the last decades, plants have been used as an alternative to conventional acaricidal drugs, as several plant compounds repel activity, decrease the reproductive potential and reduce the survival rate of ticks. For this reason, the in vitro efficacy of hexanic and hydroalcoholic extracts of Randia aculeata, Moringa oleifera and Carica papaya were evaluated against the larvae and engorged females of R. microplus. Larval packet tests and adult immersion tests were performed with seven concentrations of each of the extracts. The extracts obtained with hydroethanolic solution (polar solvent) exhibited a higher acaricidal activity than extracts prepared with n-hexane (non-polar solvent). Hydroethanolic extracts of R. aculeata seed and shell showed the highest larvicidal activity against R. microplus (100 and 91% mortality, respectively) at a concentration of 100mg/mL. Randia aculeata (seed and shell), M. oleifera and C. papaya treatments at the same concentration (100mg/mL) also resulted in adult mortality of 85, 75, 66 and 55%, respectively. The adult immersion test showed that hydroethanolic extracts derived from R. aculeata seed significantly reduced the index of egg laying and increased the percentage inhibition of oviposition of female ticks at a concentration of 100mg/mL. These results indicate that the tested extracts exhibit acaricidal activity and could be considered as potential agents for the development of alternative natural acaricides against R. microplus.

Evaluation of the acaricidal effectiveness of drug by cats notodedrosis

Relevance. Currently, the market for acaricidal drugs is very diverse. In this regard, the problem of finding effective drugs for the treatment of animal acaroses is of no small importance for practicing veterinary specialists.Methods and results. The paper deals with the issues of comparative acaricidal efficacy of aversectin ointment and amitrazine solution in cats notothedrosis. The studies were carried out on the basis of the veterinary clinic "Doctor Zoo" in Ulyanovsk. To achieve this goal, three groups of cats with notoedrosis were formed. For the treatment of animals of the first experimental group, aversectin ointment was used. Cats of the second experimental group were treated by treating the affected areas of the skin with amitrazine solution. The third group was not treated and served as a control. In the course of the study, the authors came to the conclu-sion that the amitrazine solution has a greater acaricidal activity in cat noothedrosis.

Ultrasound-assisted extraction extracts from Stemona japonica (Blume) Miq. and Cnidium monnieri (L.) Cuss. could be used as potential Rhipicephalus sanguineus control agents

Nicotiana tabacum, Stemona japonica, and Cnidium monnieri are common plants that are widely used for their anti-parasitic properties. The purpose of this study was to evaluate the acaricidal activity of extracts from these plants against the brown dog tick, Rhipicephalus sanguineus. A composition analysis of crude extracts by GC-MS was conducted to discover compounds with acaricidal effects. The toxicity of extraction against the engorged nymphs of R. sanguineus was evaluated by an immersion test. The results showed that the crude extracts of S. japonica and C. monnieri in varying ratios, concentrations, and from different extraction methods, had a killing effect on R. sanguineus. Lethality reached 76.67% ± 0.04410 when using a 1:1 extract of S. japonica:C. monnieri in 75% ethanol with ultrasonic extraction; the crude extract was determined at a concentration of 0.5 g/mL. GC-MS results showed that osthole and 5-hydroxymethylfurfural (5-HMF) are the main components of the extract. These results suggested that ultrasound-assisted extraction (UAE) extracts contained acaricidal components acting against R. sanguineus, which may result in the development of effective extracts of S. japonica and C. monnieri as a source of low-toxicity, plant-based, natural acaricidal drugs.

Psoroptes spp. in goats and sheep: Review

Psoroptes spp. are the biological agents responsible for causing psoroptic mange in sheep, goats, other ungulates, and domestic and wild animals in general. They were traditionally separated into species considering host preferences, the location of the body where they occur and the morphology of male mites. Mites on the ears of rabbits and sheep were called Psoroptes cuniculi, mites on Psoroptes equi horses and more recently, based on genetic analysis all Psoroptes spp, were reclassified in Psoroptis ovis. The disease is highly infectious, cause lesions in the dermis and secondary bacterial infections can occur in untreated animals and in conditions of weakness bringing losses and losses to breeders in general. Infestations should be controlled and eradicated by injectable and acaricidal drugs administered by dips or sprays. The quarantine of the affected animals is indicated to avoid the propagation of the mites in the herd and the environment.

Quality of life in acne patients with Demodex folliculorum and Demodex brevis mites in areas of affected skin

Objective — to compare the quality of life in acne patients with and without detected Demodex folliculorum and Demodex brevis in affected skin. Materials and methods. We studied 105 patients with acne for the presence of demodex mites. All of them were examined for the presence of Demodex folliculorum and Demodex brevis . In addition, all patients completed «Dermatology Life Quality Index» and «Cardiff Acne Disability Index» questionnaires. Results and discussion. In 19 (18.10 %) of 105 patients with acne, Demodex folliculorum and Demodex brevis mites were found in the affected areas of the facial skin. At the time of filling out the questionnaire, they characterized their skin as itchy, sensitive, painful or stinging compared to patients in whom demodex mites were not detected. 7 (6.67 %) patients had demodex mites in the past. All of them were treated with various systemic and local acaricidal drugs. This indicates the advisability of examining acne patients with pronounced subjective complaints for the presence of Demodex folliculorum and Demodex brevis mites at the sites of rash, as well as conducting individualized acaricidal treatment. Conclusions. The presence of Demodex folliculorum and Demodex brevis in patients with acne in affected areas of the facial skin influences the severity of the clinical course of dermatosis, in particular, reinforces subjective complaints, which has a negative impact on the quality of life of patients.

A model for the control of psoroptic mange in sheep

SHEEP scab became a common cause of animal suffering and production loss in British sheep flocks leading up to and following the deregulation of its statutory control in 1992 (Rose...

Resistance and control of cypermethrin and chlorpyrifos as acaricide for control of hard tick Haemaphysalis longicornis (acari: ixodidae)

Abstract : Chemotherapeutic treatment is still the foundation of tick control programs. This study investigated theacaricidal efficacy of cypermethrin alone and in combination with chlorpyrifos against Haemaphysalis (H.) longicornis.Unfed larval ticks were exposed to 0.1, 1.0, and 10 mg/mL cypermethrin for 60 min, after which the acaricidal efficacywas examined based on tick mortality. All compounds showed similar suppression curves, with the best control beingachieved by cypermethrin and chlorpyrifos (1 : 1 ratio) at 10 mg/mL. Effective cypermethrin concentrations for tickcontrol were two to seven times higher than the recommended doses, indicating resistance by H. longicornis.Keywords : acaricide, Haemaphysalis longicornis, tick control Tick-borne diseases are among the most important vector-borne diseases that cause significant losses to humans as aresult of damage to domestic and wild animals. A number ofdifferent tick control strategies have been used by livestockfarmers and animal practitioners, including grooming [10],genetic manipulation through increasing Bos indicus contentin the progeny [8], biological control in poultry [13], ento-mopathogenic fungi [15], immunological control throughproduction of vaccines against tick species [7], and ethnovet-erinary practices. Ticks transmit several disease pathogens,including Babesia and Theileria parasites, Borrelia bacteria,and the encephalomyelitis virus. To reduce or prevent thesediseases in domestic animals, control of the tick vector isnecessary. Tick monitoring is also important to detect itsearly stage. It helps to reduce the spread resistance and toobtain knowledge of distribution of acaricide resistance.Standard methods are needed to assess resistance evolutionand allow the comparison of resistance data between labora-tories. It is also important to study specific effects of selectedacaricide on specific species. There are a variety of methodsthat have been used to suppress tick vector populations [14];however, chemotherapeutic control remains the foundation oftick control programs for the eradication of livestock infesta-tions in the developing world [2]. A progressive decrease inthe efficiency of acaricidal drugs through the development ofresistance [1] would undermine this method. Epidemiologi-cal investigations have suggested that a reduction in acari-cide-treatment frequency that permits high tick attachmentrates allows for the development of endemic stability [9]. Tothis end, a regular screening of compounds is required todetermination their efficacy. Thus far, various groups of aca-ricides have been found to have significant efficacy for tickcontrol, including pyrethroids [20], avermectins, organophos-phates, organochlorines, carbamates, and insect growth regu-lators. Pyrethroid acaricides have been used for more than 40years and account for 25% of the worldwide acaricide mar-ket [3]. The pyrethroid class of acaricides was derived fromnatural compounds isolated from the Chrysanthemum genusof plants. The primary mode of pyrethroid action in bothinsects and mammals is disruption of voltage-sensitivesodium channel (VSSC) function, and any potential disrup-tor of VSSC function has potent acaricidal or toxicologicalactivity. Often, pyrethroids are sold and/or used as mixturescontaining a combination of two or more compounds. Gener-ally, the pyrethroid acaricide cypermethrin is used in combi-nation with chlorpyrifos. Chlorpyrifos is a toxic crystallineorganophosphate acaricide that inhibits acetylcholinesteraseand is used to control insect pests. The main objectives of this study were to detect the levelsof tick resistance to acaricides, to compare in vitro test meth-ods, and to investigate the lowest concentrations of cyper-methrin alone and cypermethrin in combination with chlorpyrifosfor maximum tick suppression. There is no available dataregarding the effects of these chemical compounds on thehard tick Haemaphysalis (H.) longicornis. We examined effi-

A class of promising acaricidal tetrahydroisoquinoline derivatives: synthesis, biological evaluation and structure-activity relationships.

As part of our continuing research on isoquinoline acaricidal drugs, this paper reports the preparation of a series of the 2-aryl-1-cyano-1,2,3,4-tetrahydroisoquinolines with various substituents on the N-phenyl ring, their in vitro acaricidal activities against Psoroptes cuniculi, a mange mite, and discusses their SAR as well. The structures of all compounds, including 12 new ones, were elucidated by analysis of UV, IR, NMR, ESI-MS, HR-MS spectra and X-ray diffraction experiments. All target compounds showed varying degrees of activity at 0.4 mg/mL. Compound 1 showed the strongest activity, with a 50% lethal concentration value (LC50) of 0.2421 μg/mL and 50% lethal time value (LT50) of 7.79 h, comparable to the standard drug ivermectin (LC50 = 0.2474 μg/mL; LT50 = 20.9 h). The SAR showed that the substitution pattern on the N-aromatic ring exerted a significant effect on the activity. The substituents 2'-F, 3'-F, 2'-Cl, 2'-Br and 2'-CF3 remarkably enhanced the activity. Generally, for the isomers with the same substituents at different positions, the order of the activity was ortho > meta > para. It was concluded that the target compounds represent a class of novel promising candidates or lead compounds for the development of new tetrahydroisoquinoline acaricidal agents.

Evaluation acaricidal efficacy of botanical extract from Eupatorium adenophorum against the hard tick Haemaphysalis longicornis (Acari: Ixodidae)

The aim of this study was to evaluate the acaricidal activity of a botanical extract from Eupatorium adenophorum against the hard tick Haemaphysalis longicornis. This could result in developing effective extracts of E. adenophorum as a source of natural, low-toxicity plant-based acaricidal drugs. Adult engorged females of H. longicornis were collected from naturally infected goats. The engorged females were reared in the laboratory and their offspring (larvae and nymphs) were used as test ectoparasites. The toxic effects of botanical extracts from E. adenophorum against larvae and nymphs of H. longicornis were evaluated. The results showed that the extracts with 1.5 and 1.0g/ml (w/v) concentrations were toxic for H. longicornis, comparable to a toxic effect of 2% chlorpyrifos (positive control). The median lethal time (LT50) for larval and nymphal ticks with 1.5g/ml (w/v) concentration of extract were 0.790 (LT99=1.065) and 1.018 (LT99=10.608) hours, respectively, whereas the LT50 of 1.0g/ml (w/v) concentration were 1.445 (LT99=6.047) and 1.313 (LT99=29.932) hours for larval and nymphal ticks, respectively. At a concentration of 1.5g/ml (w/v), an acaricidal effect of 100% was achieved for both larval and nymphal ticks, while a concentration of 1.0g/ml (w/v) resulted in 100% (for larvae) and 93% (for nymphs) within a 6h period. In additional, we found that the relatively low concentration (0.5g/ml) also obtained a good acaricidal effect during the short experimental period, with 2.22 and 2.651h LT50 for larval and nymphal ticks, respectively. These results indicate that E. adenophorum contains potent acaricidal ingredients against the hard tick H. longicornis.

Acaricidal activity of Melaleuca alternifolia (tea tree) oil: in vitro sensitivity of sarcoptes scabiei var hominis to terpinen-4-ol.

To compare the acaricidal activity of Melaleuca alternifolia (tea tree) oil (TTO) and some of its individual active components on the itch mite Sarcoptes scabiei var hominis. In vitro acaricide sensitivity assessment. The Menzies School of Health Research laboratory, located near the Infectious Diseases Ward of the Royal Darwin Hospital, Australia, where patients are admitted and treated for crusted scabies. Scabies mites (S scabiei var hominis) were collected from a 20-year-old Aboriginal woman admitted to the Royal Darwin Hospital with crusted scabies. Interventions Within 3 hours of collection, scabies mites were placed in continuous direct contact with the TTO products and control acaricides and were observed at regular intervals. Percentage of mites dead at regular observation intervals between 5 minutes and 24 hours during continuous exposure to the TTO products and acaricides. The 5% TTO and active component terpinen-4-ol were highly effective in reducing mite survival times. Statistically significant differences in mite survival curves were observed for 5% TTO, 2.1% terpinen-4-ol, 5% permethrin, and ivermectin (100 microg/g of Emulsifying Ointment British Pharmacopoeia 88). In vivo effectiveness was also observed. Documentation of resistance against antiectoparasitic compounds is increasing. Reported S scabiei treatment failures with lindane, crotamiton, and benzyl benzoate, as well as likely emerging resistance to 5% permethrin and oral ivermectin, are of concern and advocate for the identification and development of novel acaricidal drugs. Tea tree oil is a membrane-active biocide extracted from the tree M alternifolia. It is a principal antimicrobial in a wide range of pharmaceuticals sold in Australia, with the main active component being oxygenated terpenoids. The results suggest that TTO has a potential role as a new topical acaricide and confirm terpinen-4-ol as the primary active component.

Evaluation of oil of Cedrus deodara and benzyl benzoate in sarcoptic mange in sheep

Two commonly used acaricidal drugs in India containing oil Cedrus deodara (OCD) and benzyl benzoate (BB), respectively, were used in 24 lambs (3–6 months) naturally infected with Sarcoptes mites. The lambs were divided in three equal groups. Two groups were kept as treated groups and a third as control. Drugs were applied locally on affected parts on alternate days and recovery changes in skin lesions were observed regularly at the time of application. Blood samples from each group were collected and analysed for total erythrocytes, leukocytes, and haemoglobin concentration every 10 d Post treatment (PT). The two treated groups responded to the treatment but recovery in the C. deodara group (CDG) was faster and lesions were free from mites after 5 applications (tenth day) as compared to the seventh application (fourteenth day) in the benzyl benzoate group (BBG). Erythrocyte and leukocyte counts were significantly different in treated groups as compared to control. Animals treated with OCD had significantly more erythrocyte and leukocyte counts compared to control; however, haemoglobin did not show significant difference. Oil of C. deodara was found more efficacious in controlling sarcoptic mange in sheep.