Acaricidal Efficacy of Plants from Ecuador, Ambrosia peruviana (Asteraceae) and Lepechinia mutica (Lamiaceae) against Larvae and Engorged Adult Females of the Common Cattle Tick, Rhipicephalus microplus

Control measures against common cattle tick Rhipicephalus microplus are of the upmost importance because of considerable, deleterious impact on a farm’s economy. Due to resistance phenomena to synthetic acaricides being a constraint in affected farms, the search for plant derivatives as acaricides has increased dramatically in recent years. In this work, essential oils obtained from two Ecuadorian plants, Ambrosia peruviana and Lepechinia mutica (EOAp, EOLm), traditionally used as insecticides in indigenous communities, were studied on larvae and engorged females at the parasitic stages of R. microplus. Larvae and females were treated with five (0.0625, 0.125, 0.25, 0.50 and 1%) and six concentrations (0.125, 0.25, 0.50, 1, 2 and 4%), respectively, of each EOsAp/Lm. A 98–99% larval mortality was achieved with 0.5% of both EOsAp/Lm. EOAp inhibited oviposition and egg hatching up to 82% and 80%, respectively, and had an overall efficacy of 93.12%. Efficacy of EOLm was 72.84%, due to the low influence of EOLm on reproductive parameters. By steam distillation and GC-MS analysis, γ-Curcumene was identified as the main constituent (52.02%) in the EOAp and Shyobunol (10.80%) in EOLm. The results suggest that major components of both essential oils should be further studied as promissory acaricides against R. microplus.

Vectra 3D (dinotefuran, pyriproxyfen and permethrin) prevents acquisition of Borrelia burgdorferi sensu stricto by Ixodes ricinus and Ixodes scapularis ticks in an ex vivo feeding model

Background We evaluated the efficiency of an ex vivo feeding technique using a silicone membrane-based feeding chamber to (i) assess the anti-feeding and acaricidal efficacy of a spot-on combination of dinotefuran, pyriproxyfen and permethrin (DPP, Vectra® 3D) against adult Ixodes scapularis and Ixodes ricinus ticks, and to (ii) explore its effect on blocking the acquisition of Borrelia burgdorferi sensu stricto. Methods Eight purpose-bred dogs were randomly allocated to two equal-size groups based on body weight assessed on day 2. DPP was administered topically, as spot-on, to four dogs on day 0. Hair from the eight dogs was collected individually by brushing the whole body on days 2, 7, 14, 21, 28 and 35. On each day of hair collection, 0.05 g of sampled hair was applied on the membrane corresponding to each feeding unit (FU). Seventy-two FU were each seeded with 30 adults of I. scapularis (n = 24 FU) or I. ricinus ticks (n = 48 FU). Bovine blood spiked with B. burgdorferi sensu stricto (strain B31) was added into each unit and changed every 12 h for 4 days. Tick mortality was assessed 1 h after seeding. One additional hour of incubation was added for live/moribund specimens and reassessed for viability. All remaining live/moribund ticks were left in the feeders and tick engorgement status was recorded at 96 h after seeding, and the uptake of B. burgdorferi s.s. was examined in the collected ticks by applying quantitative real-time PCR. Results Exposure to DPP-treated hair was 100% effective in blocking B. burgdorferi s.s. acquisition. The anti-feeding efficacy remained stable (100%) against both Ixodes species throughout the study. The acaricidal efficacy of DPP evaluated at 1 and 2 h after exposure was 100% throughout the study for I. ricinus, except the 1-h assessment on day 28 (95.9%) and day 35 (95.3%). The 1-h assessment of acaricidal efficacy was 100% at all time points for I. scapularis. Conclusions The ex vivo feeding system developed here demonstrated a protective effect of DPP against the acquisition of B. burgdorferi without exposing the animals to the vectors or to the pathogen. Graphical Abstract

DURATION OF ACARICIDAL ACTION OF THE DRUG «KENEM» AND ECONOMIC JUSTIFICATION FOR THE PROTECTION OF CATTLE FROM IXODIC MITES

The scientific article presents the duration of acaricidal effect of «Kenem» drug, and its economic feasibility for protecting cattle against ixodic ticks. As a result of the study, the acaricidal efficacy and the duration of the residual acaricidal effect of drugs are important components in the planning of anti-tick measures. From a practical point of view, the economic feasibility of treating cattle against ixodic ticks in the presented conditions of acaricides in the southern regions is considered important. Despite the fact that the cost of the drug per 100 head exceeds the cost of a similar drug by 1 788.15 tenge, the frequency of its use is less, and additional installations are not required. This is due to the long duration of residual acaricidal effect of Kenem, which is 30 days, which allows to reduce the number of therapeutic measures.When calculating the economic feasibility for the use of acaricides to protect cattle against ixodic ticks, the most convenient way to prevent the sucking of ixodic ticks to animals is the local application of Kenem, which does not require special equipment and special skills of technical staff. Drug duration is 30 days, therefore the cost of its use for the entire season of active ticks per 1 animal is 44% cheaper, compared to veteran, i.e. 1,421.4 tenge.

Study on ruminant tick infestation, phytochemical analysis and in vitro acaricidal effect of Calpurnia aurea and Otostegia integrifolia extracts on Amblyomma variegatum

Ticks limit the productivity of livestock through decreased production, reproduction, increased mortality, downgrading and rejection of hides and skin. A cross-sectional study was conducted to estimate the prevalence of tick infestation in ruminant while experimental study was used to evaluate the in-vitro acaricidal efficacy of methanolic extracts: Calpurnia aurea and Otostegia integrifolia and the phytochemicals present in those extracts at different concentrations (200, 100, 50, 25, 12.5 and 6.25 mg/ml) against Amblyomma variegatum. Adult immersion was used for the in-vitro acaricidal efficacy test and plant extracts were subjected to qualitative phytochemical screening for the presence or absence of secondary metabolites using standard procedures. Out of the 160 goats, 152 sheep and 121 cattle, 23 (14.4%), 44 (28.9%) and 28 (23.1%) were found to be positive for tick infestation, respectively. The incidence of tick infestation was significantly different (p<0.01) among ruminants. Five tick spp. were identified: A. variegatum, A. gemma, R. decoloratus, R. evertsi evertsi and R. pulchellus. Extract of C. aurea and O. integrifolia was found to contain alkaloids, saponins, phlobatannin, steroids, phenolic, flavonoids, glycosides and tannins. However, both plants were found negative for triterpens. Extracts of C. aurea and O. integrifolia at 200 and 100 mg/ml concentrations showed a significantly higher (p<0.05) acaricidal activities compared to other treatments at 24 hrs post exposure. Mortality of ticks was increased with the increased dosage (concentration) and exposure time after treatment. Extracts of C. aurea showed a significantly higher (p<0.05) tick mortality (52%) compared to those of O. integrifolia (27%). This is a promising finding to have alternative means of treatment and to substitute the use of synthetic drugs which have a wide spread drug resistance especially in developing countries like Ethiopia. Key words: Calpurnia aurea; in-vitro test; Otostegia integrifolia; Phytochemical screening; Tick infestation

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.

Efficacy and safety of ethanolic Curcuma longa extract as a treatment for sand tampan ticks in a rabbit model

Background and Aim: The soft tick Ornithodoros savignyi is distributed throughout Africa, including Egypt. It primarily attacks camels, cattle, donkeys, and cows; and rarely affects humans. This study evaluated the acaricidal efficacy of ethanolic Curcuma longa extract (Turmeric) on the second nymphs of O. savignyi and then investigated the safety of this herb in rabbits. Materials and Methods: The nymphs were immersed in 10, 5, 2.5, 1.25, and 0.625 mg/ml ethanolic C. longa extract. An additional group was immersed in ethanol as a control. On the 1st, 7th, and 15th-day post-treatment, the mortality percentages, LC50 and LC95 were calculated. The ticks exposed to 10 mg/ml ethanol C. longa extract were investigated by scanning electron microscopy (SEM). Three male New Zealand White rabbits were orally administered 2 ml (two doses) of 10 mg/ml ethanolic C. longa extract, and another three rabbits were orally given two doses of 2 ml of absolute ethanol as a negative control. Histopathological examination of the kidney and liver hematology and the kidney and liver function was performed. Chemical analysis of the extract was determined by gas chromatography-mass spectrometry (GC-MS). Results: The LC50 and LC95 were 1.31 and 15.07, 1.07 and 8.56, and 0.81 and 6.97 mg/ml on the 1st, 7th, and 15th day, respectively. SEM revealed that mamillae and spots on the surfaces of the treated ticks were not discriminating except for some clefts on the surfaces. The histological examination, blood profile, and biochemical analyses revealed no significant differences between the treated and untreated rabbits (p>0.05). GC/MS analysis revealed 50 compounds, and curcumene and t umerone were found to be the major constituents of this ethanolic extract. Conclusion: The ethanolic C. longa extract produced a strong acaricidal effect on the second nymph of O. savignyi, and it was safe to use in rabbits.

In vitro repellency and contact bioassay of aqueous extracts of Cissus quadrangularis and Gomphocarpus physocarpus plants against Rhipicephalus evertsi evertsi ticks

Background The frequent use of acaricides to control ticks and inadequate flock management has led to the development of tick resistance to many acaricidal drugs. Ethno-veterinary plants with acaricidal activities have a major potential to combat this challenge because they are easily biodegradable, user-friendly, and less toxic to the environment and meat products. The objective of the study was to assess the ethnoveterinary properties of Cissus quandrangularis. Lin and Gomphocarpus physocarpus E. Mey to control ticks.Results The 6% v/v of Cissus quadrangularis for each extract were more effective (p<0.01) against Rhipicephalus evertsi evertsi ticks. The repellency percentage was highest at 6% v/v for acetone, methanol and control extracts similar to positive control Amitraz. The acaricidal efficacy of the Gomphocarpus physocarpus at 12% v/v of methanol extracts was as good as that of 6% v/v, however different to that of 18% v/v was relatively low. The mortality rate of the control, acetone was similar (p <0.05) between 6, 12 and 18% v/v at 24hrs. The mortality rate of the positive control reached 100% after 72 hrs (p < 0.05) post-treatment, even though it was similar to that of acetone, methanol and control across different concentrations. The use of acetone and methanol extracts resulted in similar tick mortality at 12 and 18% v/v at 24 hrs post-treatment. The methanol extract of Gomphocarpus physocarpus at 6% v/v reached up to 100% mortality at 72 hours similar to the positive control.Conclusions The bioassays indicated that there was a high efficacy percentage from the lowest concentrations (6% v/v) of both Gomphocarpus physocarpus E. Mey and Cissus quadrangularis. Lin plant extracts, which was similar to the positive control (Amitraz) suggesting that suggesting that 6% v/v could be sufficient for recommendations because less plant material is required.