Boophilus Annulatus Research Articles

Molecular Detection and Characterization of Bm86 Gene Homologues from Hyalomma truncatum, Rhipicephalus (Boophilus) annulatus and Rhipicephalus (Boophilus) decoloratus for the Development of an Anti-Tick Vaccine in Nigeria

The current study was conducted using prevalent Ixodid ticks from the Jos Plateau, were largely the use of acaricides has a number of drawbacks which include the development of resistant ticks, environmental pollution and toxicity. The molecular detection and characterization of Bm86 gene homologues in Hyalomma truncutum, Rhipicephalus (Boophilus) decoloratus and Rhipicephalus (Boophilus) annulatus for the first time in Nigeria was achieved and significantly important in the quest for alternative tick control strategies. GenBank Accession numbers has been assigned to the homologues as KF670599, KF670600 and KF670601 respectively and deposited as well. These results might assist in the development of a recombinant Bm86 gene based anti-tick vaccine which is an important component of an integrated control measure against hard ticks infesting livestock in the sub-Saharan Africa.

EVALUATION OF DELTAMETHRIN 7.5 % POUR ON FOR THECONTROL OF SOME ECTOPARASITES OF CATTLE AND BUFFALOES

The results of in vivo evaluation of deltamethrin 7.5 % pour on revealed that single application caused 100% elimination of Boophilus annulatus hard ticks from naturally infested cows under treatment within 2-3 weeks. There was neither any reinfestation nor undesirable side effect up to 45 days post treatment. Deltamethrin 7.5% pour on seems to be very effective against tick infested cows, safe for use and easy for application. In vitro evaluation, B. annulatus tick species exposed to hair (10 minutes) collected from cows previously treated with deltamethrin 7.5% pour on show some degree of paralysis and mortality varies according to time of collected hair post treatment. The most effective result was observed on hair collected 14 days post treatment, while hair collected 35 days post treatment was the least, since the speed of killing activity slows down gradually with time pass. The predilection site of lice, Haematopinus tuberculatus among buffaloes were the wither region (47.6%) followed by the neck and dewlap (45%), while the cheek was (0.16%) the lowest predilection site for buffaloe lice. In vivo evaluation, of deltamethrin 7.5% pour on against buffaloe's lice was 100% on day 7 post treatment compared to control group. Animal showed relief from symptoms of itching which continued for 35 days post treatment. In vitro evaluation, the mortality of lice was started 15 minutes after exposure and completed after 30 minutes from exposure to insecticide.

Efficacy of deltamethrin, diazinon, and ivermectin on Boophilus annulatus ticks (in vitro and in vivo study).

Tick infection is considered a cause of major concern as it is a vector for some disease transmission. The use of chemicals to control tick infection is increasing in farm systems. The efficacy of three chemicals was studied on the tick Boophilus annulatus. In vitro and in vivo studies were done. The active ticks were collected from naturally infected cattle for in vitro study. They were incubated with the three chemicals which are commercially used. An in vitro study recorded that the highest effect of the three chemicals was 100% at 3 h postexposure (p.e.) time for deltamethrin and 6 h for diazinon and ivermectin on the adult ticks. Egg batches were less affected. In vivo results showed more plain efficacy. The efficacy of deltamethrin was increased gradually until complete cessation of ticks showed within 3rd day posttreatment (d.p.t.), 100% efficacy. But the tick population begins to reappear gradually within 7 d.p.t., while diazinon showed 100% efficacy at 7 d.p.t. and the ticks reappear again within 14 d.p.t. The most preferred results were obtained with ivermectin which showed 100% efficacy at 7 d.p.t., and the cattle was still free from infection until 21 d.p.t. only. Ticks begin to reappear within 28 d.p.t. in slight few numbers. This concluded that the powerful and safe chemical which is commercially used was ivermectin. Even so, it is used also as an anthelmintic drug.

Functional genomics of tick vectors challenged with the cattle parasite Babesia bigemina.

Ticks are obligate hematophagous ectoparasites considered as vectors of animal diseases, having a huge economic impact in cattle industry. Babesia spp. are tick-borne pathogens that cause a disease called babesiosis in a wide range of animals and in humans. Control of tick infestations is mainly based on the use of acaricides, which have limited efficacy reducing tick infestations, mostly due to wrong usage, and is often accompanied by the selection of acaricide-resistant ticks, environmental contamination, and contamination of milk and meat products. Vaccines affecting both vector and pathogens constitute new control strategies for tick and tick-borne diseases and are, therefore, a good alternative to chemical control. In this chapter we describe the identification of Rhipicephalus (Boophilus) annulatus genes differentially expressed in response to infection with B. bigemina by using suppression-subtractive hybridization (SSH), which allows the identification of differentially expressed genes. The results of the SSH studies are validated by real-time reverse transcription (RT)-PCR. Functional analyses are conducted by RNAi on selected R. annulatus genes to determine their putative role in B. bigemina-tick interactions. Gathered data may be useful for the future development of improved vaccines and vaccination strategies to control babesiosis.

Efficacy of the entomopathogenic fungus Metarhizium brunneum in controlling the tick Rhipicephalus annulatus under field conditions

High infectivity of entomopathogenic fungi to ticks under laboratory conditions has been demonstrated in many studies. However, the few reports on their use under field conditions demonstrate large variations in their success, often with no clear explanation. The present study evaluated the factors affecting the efficacy of the fungus Metarhizium brunneum against the tick Rhipicephalus (Boophilus) annulatus. It demonstrates how environmental conditions and ground cover affect the efficiency of the fungus under field conditions. During the summer, 93% of tick females exposed to fungus-contaminated ground died within 1 week, whereas during the winter, only 62.2% died within 6 weeks. Nevertheless, the hatchability of their eggs was only 6.1% during the summer and 0.0% during winter. Covering the ground with grass, leaves or gravel improved fungal performance. Aside from killing female ticks, the fungus had a substantial effect on tick fecundity. Fungal infection reduced the proportion of female ticks laying full-size egg masses by up to 91%, and reduced egg hatchability by up to 100%. To reduce the negative effect of outdoor factors on fungal activity, its conidia were mixed with different oils (olive, canola, mineral or paraffin at 10% v/v) and evaluated in both laboratory and field tests for efficacy. All tested oils without conidia sprayed on the sand did not influence tick survival or weight of the laid eggs but significantly reduced egghatchability. Conidia in water with canola or mineral oil spread on agarose and incubated for 18h showed 57% and 0% germination, respectively. Comparing, under laboratory conditions, the effects of adding each of the four oils to conidia in water on ticks demonstrated no effect on female mortality or weight of the laid egg mass, but the percentage of hatched eggs was reduced. In outdoor trials, female ticks placed on the ground sprayed with conidia in water yielded an average of 175 larvae per female and there was no hatching of eggs laid by females placed on ground sprayed with conidia in water with canola or mineral oils.

Inhibition of the recombinant cattle tick Rhipicephalus (Boophilus) annulatus glutathione S-transferase

Rhipicephalus (Boophilus) annulatus is a bloodsucking ectoparasite that causes severe production losses in the cattle industry. This study aims to evaluate the in vitro effects of tannic acid, hematin (GST inhibitors) and different plant extracts (rich in tannic acid) on the activity of the recombinant glutathione S-transferase enzyme of the Egyptian cattle tick R. annulatus (rRaGST), in order to confirm their ability to inhibit the parasitic essential detoxification enzyme glutathione S-transferase. Extraction with 70% ethanol of Hibiscus cannabinus (kenaf flowers), Punica granatum (red and white pomegranate peel), Musa acuminata (banana peel) (Musaceae), Medicago sativa (alfalfa seeds), Tamarindus indicus (seed) and Cuminum cyminum (cumin seed) were used to assess: (i) inhibitory capacities of rRaGST and (ii) their phenolic and flavonoid contents. Ethanol extraction of red pomegranate peel contained the highest content of phenolic compounds (29.95mg gallic acid/g dry tissue) compared to the other studied plant extracts. The highest inhibition activities of rRaGST were obtained with kenaf and red pomegranate peel (P. granatum) extracts with IC50 values of 0.123 and 0.136mg dry tissue/ml, respectively. Tannic acid was the more effective inhibitor of rRaGST with an IC50 value equal to 4.57μM compared to delphinidine-HCl (IC50=14.9±3.1μM). Gossypol had a weak inhibitory effect (IC50=43.7μM), and caffeic acid had almost no effect on tick GST activity. The IC50 values qualify ethacrynic acid as a potent inhibitor of rRaGST activity (IC50=0.034μM). Cibacron blue and hematin showed a considerable inhibition effect on rRaGST activity, and their IC50 values were 0.13μM and 7.5μM, respectively. The activity of rRaGST was highest for CDNB (30.2μmol/min/mg protein). The enzyme had also a peroxidatic activity (the specific activity equals 26.5μmol/min/mg protein). Both tannic acid and hematin inhibited rRaGST activity non-competitively with respect to GSH and competitively with respect to CDNB. While red pomegranate extracts inhibited rRaGST activity competitively with respect to GSH, uncompetitive inhibition was observed with respect to CDNB.

Low level deltamethrin resistance in ticks from cattle of Kerala, a south Indian state

The deltamethrin resistance status in Rhipicephalus (Boophilus) annulatus and R. (B.) microplus ticks collected from cattle of five organized farms of Kerala, south India was evaluated. Resistance was characterized using biological (larval packet test), biochemical (esterase enzyme activity assay) and molecular tools (PCR amplification and sequencing of deltamethrin resistance-associated genes). Characterization of field isolates revealed level I resistance in ticks collected from four out of five farms. Elevated level of α/β esterase activity was not recorded in isolates showing level I resistance. Previously reported point mutations in the carboxyl esterase (G1120A) and sodium channel (T2134A and C190A) genes were not observed in any of the field isolates. The present study showed a low level (level I) resistance is developed in the most economically important ticks infesting cattle of this state and it cautions the development of large scale resistance in future.

Phylogenetic analysis of mitochondrial genome sequences indicates that the cattle tick, Rhipicephalus (Boophilus) microplus, contains a cryptic species

Cattle ticks of the subgenus Rhipicephalus (Boophilus) are major agricultural pests worldwide, causing billions of dollars in losses annually. Rhipicephalus (Boophilus) annulatus and R. microplus are the most well-known and widespread species, and a third species, R. australis, was recently reinstated for ‘R. microplus’ from Australia and parts of Southeast Asia. We use mitochondrial genome sequences to address the phylogenetic relationships among the species of the subgenus Boophilus. We sequenced the complete or partial mitochondrial genomes of R. annulatus, R. australis, R. kohlsi, R. geigyi, and of three geographically disparate specimens of R. microplus from Brazil, Cambodia and China. Phylogenetic analyses of mitochondrial genomes, as well as cox1 and 16S rRNA sequences, reveals a species complex of R. annulatus, R. australis, and two clades of R. microplus, which we call the R. microplus complex. We show that cattle ticks morphologically identified as R. microplus from Southern China and Northern India (R. microplus clade B) are more closely related to R. annulatus than other specimens of R. microplus s.s. from Asia, South America and Africa (R. microplus clade A). Our analysis suggests that ticks reported as R. microplus from Southern China and Northern India are a cryptic species. This highlights the need for further molecular, morphological and crossbreeding studies of the R. microplus complex, with emphasis on specimens from China and India. We found that cox1 and, to a lesser extent, 16S rRNA were far more successful in resolving the phylogenetic relationships within the R. microplus complex than 12S rRNA or the nuclear marker ITS2. We suggest that future molecular studies of the R. microplus complex should focus on cox1, supplemented by 16S rRNA, and develop nuclear markers alternative to ITS2 to complement the mitochondrial data.

Rickettsia africae and Candidatus Rickettsia barbariae in Ticks in Israel

DNA of several spotted fever group rickettsiae was found in ticks in Israel. The findings include evidence for the existence of Rickettsia africae and Candidatus Rickettsia barbariae in ticks in Israel. The DNA of R. africae was detected in a Hyalomma detritum tick from a wild boar and DNA of C. Rickettsia barbariae was detected in Rhipicephalus turanicus and Rhipicephalus sanguineus collected from vegetation. The DNA of Rickettsia massiliae was found in Rh. sanguineus and Haemaphysalis erinacei, whereas DNA of Rickettsia sibirica mongolitimonae was detected in a Rhipicephalus (Boophilus) annulatus. Clinicians should be aware that diseases caused by a variety of rickettsiae previously thought to be present only in other countries outside of the Middle East may infect residents of Israel who have not necessarily traveled overseas. Furthermore, this study reveals again that the epidemiology of the spotted fever group rickettsiae may not only involve Rickettsia conorii but may include other rickettsiae.

Studies on prevalence, risk indicators and control options for tick infestation in ruminants

An epidemiological study was conducted at Benisuef district to determine the current situation and associated determinants of tick infestations in ruminants and to assess the efficacy of three different types of insecticides against tick infestation under field conditions. Total of (1082) animals of different species (540 cattle, 230 buffaloes, 108 of each sheep & goats and 96 camels) were selected randomly and examined carefully for tick infestation. About (30.1%) of total observed animals were found tick infested with highest rate in cattle (60.5%) followed by goats (25.9%), buffaloes (17.8%), sheep (14.8%) while no tick infestation recorded in camels. The most prevalent tick's species affecting ruminants was Boophilus annulatus (26.5%) followed by Hyalomma anatolicum (6.1%) then Rhipicephalus turanicus (3.4%). Regarding the associated risk factors, tick infestation was found statistically significant (P < 0.05), as the highest infestation rates were recorded in Friesian cow's breed (77.5%), older ages, >3 years (78.8%) followed by at age, ≤2 months (57.8%) and during summer months were found highly significant (P < 0.01) in cattle ( 76.5%) followed by goats and sheep (33.3% & 22.9% resp.,) comparing with results in winter. The preferred sites of ticks' attachment to infested animals were udders and external genitalia (70.7% of each) then Neck & chest (63.0% of each), inner thighs (61.1%), perineum (41.7%), ears (14.6%), around eyes (11.7%). The obtained results revealed that poor husbandry practices of small holder farmers be a determinant making the animals more prone to tick infestation in this district. Improving the hygienic conditions associated with treatment of infested cattle with Ivermectin (0.2 mg/kg b.wt, S/C) and spraying of Deltamethrin (1%) for surrounding environment twice every 14 days are recommended for control of tick infestation under field condition.

Survey on cattle ticks in Nur, north of Iran

To survey the prevalence of cattle ticks in Nur County and prepare a list of tick fauna in this district. This investigation was carried out on 150 head of cattle ticks of rural areas of Nur city which is located in Mazandaran province during spring and summer seasons of 2011. The collected ticks were identified using light microscope and available systematic keys. A total number of 1 563 ticks were isolated from examined cattle and their genus and numbers including: Ixodes ricinus 51% (111 male and 691 female) and Boophilus annulatus 49% (83 male and 678 female), respectively. Results of the current investigation indicate the presence of two species of acarine ectoparasites which have potential health risk Ixodes ricinus and Boophilus annulatus. More studies are required to increase our data concerning ticks and other ectopreasites of ruminants in other areas of Mazandaran province and should be noted to their ability in transmission of infectious agents.

Comparison of in vitro acaricidal effects of commercial preparations of cypermethrin and fenvalerate against Rhipicephalus (Boophilus) annulatus

Commercially available preparations of cypermethrin (Clinar and Ectomin) and fenvalerate (Flytik and Ticomax, 20% E.C) were compared for their acaricidal activity against Rhipicephalus (Boophilus) annulatus using adult immersion test. Adult tick mortality was higher with Ectomin compared to Clinar. Complete eclosion blocking was observed at all the tested concentrations with Ectomin while it was observed only at the highest concentration tested for Clinar. Compared to Flytik, adult tick mortality was higher with Ticomax at the tested concentrations. Complete blocking of hatching of laid ova was observed with Flytik at the highest concentration tested. At the manufacture recommended dosage of 200 ppm Ectomin elicited 93.37 per cent inhibition of fecundity, while it was 91.7 per cent for Clinar. For fenvalerate, the recommended concentration was 1200 ppm at which Ticomax showed 86 per cent and Flytik produced 80.05 per cent inhibition of fecundity respectively.

Retrospective Study of Hemoparasites in Cattle in Southern Italy by Reverse Line Blot Hybridization

ABSTRACTTick-borne diseases are widespread in tropical and temperate regions and are responsible for important economic losses in those areas. In order to assess the presence and prevalence of various pathogens in southern Italy, we retrospectively analyzed cattle blood samples collected for a previous study in 2000 using reverse line blot (RLB) hybridization. The study had been carried out in three regions of southern Italy on 1,500 randomly selected and apparently healthy adult cattle. RLB showed that 43.7% of the cattle were positive for nine different species of hemoparasites with either a single infection or a mixed infection. Theileria buffeli was the most common species found, being present in 27.3% of the animals, followed by Anaplasma marginale in 18.1%, Anaplasma centrale in 13.8%, Babesia bigemina and Anaplasma bovis in 4.2%, Anaplasma phagocytophilum in 1.7%, Babesia bovis in 1.6%, Babesia major in 0.2% and Babesia divergens in 0.1%. Complete blood counts showed different degrees of anemia in 363 animals (24.2%) and of these, 169 were RLB-positive for at least one pathogen. Among the ticks that were collected from the cattle, the following species were identified: Rhipicephalus bursa, Ixodes ricinus, Hyalomma marginatum, Boophilus annulatus, Dermacentor marginatus and Haemaphysalis (sulcata, parva, inermis and punctata). The results obtained confirmed the spread of endemic tick-borne pathogens in the regions studied.

Dynamique d’activité saisonnière des tiques ixodidés parasites des bovins dans deux étages bioclimatiques du nord-est algérien

Un suivi mensuel de l’infestation par les tiques de 48 bovins choisis dans six elevages a ete realise entre avril 2006 et mars 2007 en Algerie dans les localites de Mila (etage bioclimatique semi-aride) et d’El Tarf (etage bioclimatique humide). Au total, 7 024 tiques appartenant a quatre genres et dix especes d’ixodides ont ete collectees : Rhipicephalus (Boophilus) annulatus (62,7 p. 100 des tiques collectees), R. turanicus (13,6 p. 100), Hyalomma scupense (13,6 p. 100), R. bursa (7,7 p. 100), H. marginatum (4,7 p. 100), H. excavatum (3,9 p. 100), H. anatolicum (2,3 p. 100), Haemaphysalis punctata (1,5 p. 100), Ixodes ricinus (0,7 p. 100) et Hyalomma lusitanicum (0,4 p. 100). L’espece la plus frequente dans la wilaya (collectivite publique territoriale) d’El Tarf a ete R. annulatus (77,7 p. 100). En revanche, H. scupense (39,2 p. 100) et R. bursa (17,7 p. 100) ont ete dominants dans la wilaya de Mila. De nombreuses especes de Hyalomma et de Rhipicephalus ont eu une activite continue durant l’annee avec une intensite d’infestation maximale en ete pour R. annulatus et H. scupense, et vernale a automnale pour R. bursa. L’abondance des especes mesophiles a ete faible. Elles ont eu une activite hivernale pour I. ricinus, present uniquement a El Tarf, et automnale pour Hae. punctata, observee uniquement a Mila. L’intensite d’infestation a ete significativement plus elevee chez les bovins adultes que chez les bovins ages de moins d’un an. La phenologie des differentes especes de tiques a parfois differe en fonction des pays limitrophes, montrant ainsi une grande adaptabilite des tiques et la necessite de realiser des etudes regionales avant la mise en place de tout programme de lutte contre les tiques ou les pathogenes qu’elles transmettent.

An overview of factors responsible for geographic distribution pattern of ixodid ticks in the Sudan

Tick fauna in the Sudan comprises over 70 species prevalent in diverse ecological zones. Among these are the most economically important ticks in Africa, namely Rhipicephalus appendiculatus, Hyalomma anatolicum, Amblyomma variegatum, Amblyomma lepidum, Rhipicephalus (Boophilus) decoloratus and Rhipicephalus (Boophilus) annulatus. Several factors determine the dynamic changes of tick distribution in the Sudan. These are animal movement either for trade, nomadism, or migration due to civil unrest etc., habitat modification such as deforestation, large-scale mechanized cultivation and urbanization; drought and desertification, and global climate change. The accelerated change in tick distribution results in outbreaks of several tick-borne diseases. Examples of these are East Coast fever, tropical theileriosis, malignant ovine theileriosis, heartwater and babesiosis by Babesia bovis. Emergence of these diseases in districts believed to be free is alarming and has adverse effects in the process of animal resources development. This communication discusses distribution patterns of the economically important livestock ticks in the Sudan and identifies new zones where ticks have established and the possible factors determining such distribution.Keywords: Distribution, Factors, Livestock, Sudan, Ticks.

Distribution of ixodid ticks on dogs in Nuevo León, Mexico, and their association with Borrelia burgdorferi sensu lato

This study aimed to document the geographic distribution of Ixodes tick species in dogs and the prevalence of Borrelia burgdorferi s.l. in adult ticks and blood samples by amplification of the ospA region of the B. burgdorferi genome. The study area included nine localities in Nuevo León state. DNA amplification was performed on pools of ticks to calculate the maximum likelihood estimation (MLE), and the community composition (prevalence, abundance, and intensity of infestation) was recorded. A total of 2,543 adult ticks, representing four species, Rhipicephalus sanguineus, Dermacentor variabilis, Rhipicephalus (Boophilus) annulatus, and Amblyomma cajennense, were recorded from 338 infested dogs. Statistically significant correlations were observed between female dogs and infestation (P=0.0003) and between R. sanguineus and locality (P=0.0001). Dogs sampled in Guadalupe and Estanzuela were positive by PCR (0.9%) for B. burgdorferi. Rhipicephalus sanguineus had the highest abundance, intensity, and prevalence (10.57, 7.12 and 94.6, respectively). PCR results from 256 pools showed that four pools were positive for D. variabilis (1.6%), with an MLE of 9.2%; nevertheless, it is important to consider that in the area under examination probably other reservoir hosts for D. variabilis and B. burgdorferi are present that, very likely, play a much more important role in the ecology of Lyme borreliosis than dogs, which could be considered in future studies.

Ixodid ticks of traditionally managed cattle in central Nigeria: where Rhipicephalus (Boophilus) microplus does not dare (yet?).

BackgroundTicks and tick-borne diseases (TBDs) undermine cattle fitness and productivity in the whole of sub-Saharan Africa, including Nigeria. The aim of this study was to document the composition of tick species, assessing the burden of infestation, in traditionally managed cattle in an area of central Nigeria where acaricides have not been used historically.MethodsThe study was carried out in September 2010 in 9 villages belonging to three neighbouring local government areas in Plateau State, Nigeria. In each village all visible adult ticks were collected from at least 15 cattle (mean number = 25). Collected ticks were preserved in 70% ethanol to be counted and morphologically identified to the species level.ResultsA total of 5011 ixodid ticks (1935 males and 3076 females) were collected from 228 cattle, comprising 14 calves, 33 juveniles, and 181 adults. Three tick genera (i.e., Amblyomma, Hyalomma, and Rhipicephalus, including the Boophilus sub-genus) and 11 species were identified. The most prevalent species was Rhipicephalus (Boophilus) decoloratus (41.4%), followed by Rhipicephalus (Boophilus) annulatus (15.4%), Rhipicephalus guilhoni (12.0%), Rhipicephalus (Boophilus) geigyi (7.6%), Hyalomma truncatum (7.4%), Amblyomma variegatum (6.3%), Rhipicephalus simus Group (4.0%), Rhipicephalus turanicus (1.2%), Rhipicephalus sanguineus (0.3%), Hyalomma rufipes (0.2%), and Rhipicephalus lunulatus (n = 1). Mean tick loads recorded were relatively high (22 ± 1.4), in spite of the practice of hand removal of ticks traditionally undertaken by the Fulani pastoralists in the area. Calves bore a significantly lower tick burden than adults (p = 0.004). Rhipicephalus (Boophilus) microplus was not found in the area, suggesting that the eastbound expansion of this tick species in West Africa, has not yet reached central Nigeria.ConclusionsThis study ascertained the presence of a broad variety of cattle tick species, most of which are of veterinary importance. The presence of each tick species is correlated with the potential occurrence of tick-borne pathogens and suggestions for tick control in the area are considered. Results should assist the diagnosis of related TBDs in cattle as well as the strategic planning of cost-effective tick control.

Effect of Allium sativum and Allium cepa oils on different stages of Boophilus annulatus

The study is aimed to investigate the acaricidal effect of Allium sativum (garlic) and Allium cepa (onion) oils on different stages of Boophilus annulatus hard tick. Engorged B. annulatus females were collected from naturally infected cattle. A number of engorged ticks were incubated at 28°C and 85% relative humidity to lay eggs, which were incubated to obtain larvae that were used in the study. The used garlic and onion oils were prepared by steam distillation and were analyzed by gas chromatography. These oils were dissolved in ethanol, methanol alcohols, and, partially, in water. The oils were tested in different concentrations; 1, 2, 5, 10, and 20%. These concentrations were applied on adult ticks by adult immersion test; on larvae by larval immersion technique and on eggs. The 20, 10, and 5% of garlic oil dilutions in ethanol and methanol killed all adult ticks and larvae within 24h. Similar results were obtained for 10 and 20% garlic oil dissolved in water. The effect of 10% aqueous solution of garlic oil on embryonated eggs was clear as its addition to these eggs led to their in ability to hatch, deformity in shape, and change in color. The 10 and 20% onion oil in ethanol and methanol alcohols killed 76-86% of the adult ticks within 72h post-application. While, all larvae died within 24h postsubjected to these two concentrations. These concentrations (10 and 20%) of onion oil in water killed 56-80% of the treated ticks. Moreover, 10% aqueous solution of onion oil prevented hatching of embyonated eggs. We concluded that garlic and onion oils have acaricidal effect on all stages of B. annulatus at concentrations higher than 5%. Only garlic oil could kill 100% of adult ticks at concentrations from 5% in alcohols.

The Role of Phylogeny on the Taxonomy and Nomenclature of Ixodid Ticks

The phylogenies based on nucleotide sequences using distance and neighbor-joining methods were congruent. The ITS-2 DNA region was amplified from Boophilus annulatus (Say, 1821) and Rhipicephalus sanguineus (Latreille, 1806) and was sequenced and analyzed to clarify the phylogenetic relationship of these Boophilus and Rhipicephalus species. The data suggested that the gene shared a similarity in sequence compared to ticks ITS-2 found in Gen Bank. The results indicated that the ITS-2 nucleotide sequence of B. annulatus strain Egypt and R. sanguineus strain Egypt reflected the phylogenetic relationship between the two species.

Effects of fipronil against Rhipicephalus (Boophilus) annulatus

Acaricidal effects of fipronil against Rhipicephalus (Boophilus) annulatus were studied in vitro using adult immersion test. A concentration-dependent increase in adult mortality was observed. At a concentration of 1 ppm, there was 100% inhibition of fecundity. Complete blocking of hatching of the laid ova was observed even at 500 ppb. Based on probit analysis, the 50% lethal concentration value was calculated as 12.78 ppm, which was much higher than the previously reported values against Rhipicephalus (Boophilus) microplus.