Tick control

Ticks feed on blood, are vectors of tickborne diseases and cause considerable skin damage to livestock. They are commonly controlled using commercial acaricides, which are expensive to the rural farmers, causing them to resort to alternative tick control methods. The objective of this study was to assess the acaricidal properties and safety of some materials (Ptaeroxylon obliquum, Aloe ferox, Lantana camara, Tagetes minuta, Used engine oil and Jeyes fluid, used by rural farmers to control cattle ticks in the Eastern Cape Province, South Africa. A total of 52 cattle were divided into 13 experimental groups with 4 cattle in each. Jeyes fluid at 76.8% concentration and Used engine oil had an efficacy that was almost similar to that of the positive control Ektoban® (Cymiazol 17.5 and cypermethrin 2.5%). Extracts of L. camara at 40% concentration had an efficacy of 57% while A. ferox, P. obliquum and T. minuta were not effective. The test materials had no irritation effect on rats. The study revealed that the materials rural farmers use as acaricides vary in their efficacy in controlling ticks.

From 1995 to 1999, four experiments were conducted on greenhouse roses to assess the effectiveness of the nC24 petroleum spray oil (PSO), D-C-Tron Plus, against two-spotted mite, Tetranychus urticae Koch (Acarina: Tetranychidae), and to determine how the oil could be most efficiently and effectively used in combination with the predatory mite Phytoseiulus persimilis Athias-Henriot (Acarina: Phytoseiidae) in an integrated pest management program. The results showed that 0.5% PSO applied fortnightly to roses gave excellent protection from T urticae infestation when the mite population was not already established. However, PSO applied after roses were infested with T. urticae above the economic threshold only stabilised populations without reducing them below that threshold. Populations of P. persimilis in the upper and lower canopies were unchanged after two sprays of PSO at 7-day intervals, and application of PSO to the upper canopy was as effective in controlling T. urticae in the p...

An oil extracted from the leaves of a tropical shrub Ocimum suave was found to repel as well as kill all stages of the tick Rhipicephalus appendiculatus. In an in vitro bioassay for the larvae, the LC50 of the oil in liquid paraffin was 0.024%. A 10% solution was found to kill all immatures and more than 70% of adults feeding on rabbits. Rabbits were protected for 5 days against attaching larvae using a 10% solution. Preliminary experiments undertaken with cattle kept in the field suggest that the oil may have potential in tick control, and a role in integrated tick management.

The use of insecticides is still the basic procedure for controlling most ectoparasites, but various methods are being developed to act in addition to, or in synergy with these products, so as to enhance the efficacy and reduce the adverse effects of insecticides, by contributing to ecologically acceptable strategies. These methods are classified as ecological control (modification of the environment of the parasite), biological control (predation, parasitism, action of pathogens, etc.), genetic control (release of sterile males, hybridisation, genetic manipulations) and mechanical control (insect traps, use of repellents). The application of such methods depends on the biological and ecological characteristics of the ectoparasite, and they may act directly or indirectly, affecting mortality and/or reproduction. The authors review the principal methods applicable to major groups of ectoparasites of veterinary interest. Non-chemical methods are the subject of wide-ranging and promisi...

Conidia of the entomopathogenic fungus, Metarhizium anisopliae, in oil/water formulation (1 9 10 8 conidia/ml) were sprayed at 3 weekly intervals on Rhipicephalus evertsi evertsi and Rhipicephalus (Boophilus) decoloratus ticks while feeding on Afrikana bulls grazing in paddocks for a period of 1 year. The fungus reduced the on-host tick populations by 83% 3 month after commencement of the experiment. The formulation by itself had only minimal effect on the tick population. Tick populations and fungal efficacy were highest at the peaks of rainfall and relative humidity or soon thereafter. Fed and unfed adult R. e. evertsi and R. (B.) decoloratus collected at the end of the experiment from the fungus-sprayed and from the control cattle and incubated in the laboratory exhibited a mortality of 93% in oil formulated conidia and 14% in oil control. The corresponding mortality in R. (B.) decoloratus was 100% in fungus and 11% in oil control. Ticks on the fungus-sprayed groups had significantly higher mortality (P \ 0.05) than on the control groups. Furthermore, no significant difference (P \ 0.05) was observed in fungus-induced mortality between the two tick species. Mortalities induced by Triton X-100 (0.05%), sunflower oil (20%) and water alone were low, suggesting that they were non-toxic to ticks at the concentrations used and no significant difference was observed among them. No physical or behavioral abnormalities were observed in the fungus-sprayed cattle at any time during the course of the experiment. All groups of cattle gained weights during the experimental period.

The purpose of this work was to evaluate the in vitro virulence of three isolates of Metarhizium anisopliae var. anisopliae to eggs and larvae of the tick Boophilus microplus. The fungus tested was isolated from engorged females of B. microplus collected in the field, and identified as Ma01, Ma02 e Ma04. These isolates were evaluated by immersion of eggs and larvae in suspension with different conidial concentrations: 105, 106, 107 e 108 conidia/ml. In each isolate there was a treatment group for each spore concentration and a control group with 10 repetitions. It was observed in the treated egg groups that there was a hatching percentage that was much less than that observed in the control groups. This was in inverse proportion to the conidia concentration/ml. Larval bioassays of all the tested isolates resulted in a high mortality of larvae in direct proportion to the spore concentration/ml, 10 days after the conidia suspensions were inoculated. To consolidate the infection, the fungus used in bioassays was re-isolated. (© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

The efficacy of a single treatment with a 12.5% pyriprole spot-on formulation against induced infestations with R. sanguineus ticks and cat fleas (C. felis) as well as its persistence after repeated washing and shampooing was investigated in four separate studies. In a first study on R. sanguineus involving 32 beagle dogs, the efficacy at various time-points during the 30 days that followed treatment assessed 48 h after re-infestation ranged from 100% to 99.3%. No engorged ticks, alive or dead, were found in the treated animals. Shampooing 2 days after treatment and weekly washings did not affect the efficacy. In a second study on R. sanguineus involving 32 beagle dogs, the efficacy at various time-points during the 30 days that followed treatment assessed 48 h after re-infestation ranged from 100% to 96.8%. Single washing 8 h after treatment and single shampooing 24 h after treatment had no negative impact on the efficacy of the product. In a third study on C. felis involving 28 beagle dogs, the efficacy at various timepoints during the 30 days that followed treatment assessed 48 h after re-infestation was always 100% and weekly washings did not diminish the efficacy. In a last study on C. felis involving 24 beagle dogs, the efficacy at various time-points during the 5 weeks that followed treatment assessed 48 h after re-infestation ranged from 100% to 99.8%, and shampooing 24 h after treatment did not reduce the efficacy. The product was well tolerated by the dogs. #

The acaricidal efficacy of nine marketed products, i.e. Acardust, Acarosan (foam and powder), Actelic 50, Artilin 3A (spirit and water base), liquid nitrogen, Paragerm AK, and Tymasil, and of intensive vacuum-cleaning have been compared on four different test surfaces: mattress, tufted carpet, gypsum board and rough wooden board, all covered with artificial house dust. They were inoculated with the house dust mite, Dermatophagoides pteronyssinus or the house-dust fungus Aspergillus repens for evaluation of the fungistatic claims of some products. The acaricidal activity of Tymasil did not surpass that of vacuuming; its fungistatic effect was not apparent. The other products showed complete to almost complete eradication on at least one of the substrates tested. Taking into account the results of acaricidal efficacy as well as the data on safety and practicality acquired earlier, Acarosan powder was considered first choice for carpet treatment. Acarosan and liquid nitrogen, were found to be effective in the treatment of mattress, pillow, upholstered furniture and heavy curtains. On wooden surfaces Acarosan was found to be both effective and safe, while Acardust, Actelic 50, Artilin 3A (both fungistatic as well as acaricidal), liquid nitrogen and Paragerm also passed the efficiency test.

Ticks and tick-borne diseases affect animal and human health worldwide and are the cause of significant economic losses. Approximately 10% of the currently known 867 tick species act as vectors of a broad range of pathogens of domestic animals and humans and are also responsible for damage directly due to their feeding behaviour. The most important tick species and the effects they cause are listed. The impact on the global economy is considered to be high and although some estimates are given, there is a lack of reliable data. The impact of ticks and tick-borne diseases on animal production and public health and their control are discussed.

Like all parasites, ticks can be spread easily along with their hosts. Ticks are obligate parasites of vertebrates, to which they attach themselves for varying periods of time, and are well-adapted to this mode of transport. Once the transport stage is complete and they have detached at destination, they are also able to wait several months for the arrival of a new host on which they will continue their life cycle. This leads to the establishment of a secondary tick population. Two tropical cattle tick species, Rhipicephalus microplus and Amblyomma variegatum, have perfected this strategy of colonisation and occupation of favourable zones. Rhipicephalus microplus, which originated from South and Southeast Asia, is highly specific for ungulates, and thanks to cattle movements it has spread throughout the tropical belt, apart from the remotest areas. Amblyomma variegatum, which originated in Africa, was transported to Madagascar and the Mascarene Islands, as well as to the West Indies...

Honey bee (Apis mellifera) colonies are declining, and a number of stressors have been identified that affect, alone or in combination, the health of honey bees. The ectoparasitic mite Varroa destructor, honey bee viruses that are often closely associated with the mite, and pesticides used to control the mite population form a complex system of stressors that may affect honey bee health in different ways. During an acaricide treatment using Apistan (plastic strips coated with tau-fluvalinate), we analyzed the infection dynamics of deformed wing virus (DWV), sacbrood virus (SBV), and black queen cell virus (BQCV) in adult bees, miteinfested pupae, their associated Varroa mites, and uninfested pupae, comparing these to similar samples from untreated control colonies.

In order to continue to produce livestock in a sustainable fashion, it is suggested that what was used in the past will continue to form the mainstay of future control. For the foreseeable future, we must conserve what we have, and use it in combination with all the principles of integrated pest management, namely strategic and focussed treatments of animals, environmental control of breeding sites, disease management (including the principles of enzootic stability), and resistant breeds. Whilst new technologies, such as the development of vaccines both against the insect pest in some cases or the disease they transmit in others, and genetic engineering hold out some hope for the future; these are not sufficiently well advanced to permit wholesale application.

Ticks and tick-borne diseases are a global problem and considered as a major obstacle in the health and product performance of animals which reflects impact on the livelihood of resource-poor farming communities. Tick control is practiced in a variety of methods including vaccination involving different livestock system. At present, periodic application of chemical acaricides is the most commonly used method of tick control especially among the small and marginal farmers of India. Resistance to existing chemical acaricides is widespread, and newer classes of acaricides have tended to be significantly more expensive. Presently, there is increasing concern about the use of chemicals in all forms of agriculture as well as livestock management by their potential environmental hazard and presence in food products. The use of herbal preparations among the rural folks is gaining importance because of their strong belief for folded benefits. Integrated control of ticks is the combination of...

Tick-borne diseases occurring in Zambia are assuming more importance as they continue to be a major economic problem not only in Zambia, but in many parts of Eastern, Southern and Central Africa. The current control methods, which include the use of toxic acaricides to kill ticks, and the virulent sporozoite infection and treatment method have limitations. Recombinant vaccines, currently in their experimental stages, offer hope for the future. The use of acaricides is hampered by the development of acaricide resistance and live vaccines are dependent on cold chain facilities, which are a formidable obstacle in the poorly developed infrastructure in parts of Zambia where the vaccine is most needed. Amidst these drawbacks are the results of the recent research on parasites and vector recombinant vaccines which promise to circumvent these problems. The history, current status and attitudes regarding the control of these diseases, taking into account their complexity, are reviewed. The establishment of the well-designed Central Veterinary Research Institute (CVRI) and Japanese International Cooperation Agency (JICA) sponsored veterinary school, both have a potential for high quality research, with access to a wealth of specimens a veritable goldmine of research material. It is thus hoped that this review will stimulate the desire to maximize the value of the tick and tick-borne disease research in both Zambia and the international research community.

Seven treatments for the control of Varroa destructor (Anderson & Trueman) were tested to determine the optimum timing of miticide application. Threshold mite levels indicating miticide application were determined for three possible treatment dates: April, August, and October. The treatments were as follows: (1) ßuvalinate in April, (2) ßuvalinate in August, (3) ßuvalinate in October, (4) ßuvalinate in April and October, (5) ßuvalinate applied continuously (except during honey ßow) with replacement every 42 d, (6) control (no treatment), and coumaphos in April. The number of miticide applications in a season had no effect on brood area or colony bee population a year after initiating the experiment. However, the absence of any treatment signiÞcantly reduced brood area and colony bee population and signiÞcantly increased colony mite population. Date of treatment had signiÞcant effects on colony mortality rates, mite levels, and brood area the following spring. When coupled with sampling and threshold recommendations, a single, late-season application of ßuvalinate is as effective for the control of V. destructor as semiannual or continuous miticide applications. Treatment thresholds were recommended for ether roll and 48-h sticky board sampling methods in April (three and 24 mites, respectively) and August (14 and 46 mites, respectively) and for ether rolls in October (three mites) in cold climates.

Hyalomma scupense (syn. Hyalomma detritum) is a two-host domestic endophilic tick of cattle and secondarily other ungulates in the Maghreb region (Africa). This species transmits several pathogens, among which two are major livestock diseases: Theileria annulata and Theileria equi. Various other pathogens are also transmitted by this tick species, such as Anaplasma phagocytophilum and Ehrlichia bovis. Hyalomma scupense is common in sub-humid and semi-arid areas of several regions in the world, mainly in the Maghreb region. In this region, adults attach to animals during the summer season; larvae and nymphs attach to their hosts during autumn, but there is a regional difference in H. scupense phenology. There is an overlap between immature and adult ticks, leading in some contexts to a dramatic modification of the epidemiology of tick-borne diseases. This tick species attaches preferentially to the posterior udder quarters and thighs. Tick burdens can reach 130 ticks per animal, with...

Greenhouse experiments were conducted on various crops (cucumber, tomato, eggplant, green bean) to ascertain the effects of Break-thru Ò (polyether-polymethylsiloxane-copolymer, a silicone surfactant) and an oil emulsion, on Beauveria bassiana (Balsamo) Vuillemin (Bb) applications for the control of the two spotted spider mite, Tetranychus urticae Koch. The objectives were to compare a) the efficacy of Bb control when applied in aqueous Break-thru Ò or an oil emulsion; b) the effects of various concentrations of Bb conidia, as affected by each surfactant; and c) the effects of Break-thru Ò on the activity of the fungus. Conidia were suspended either in an aqueous Break-thru Ò or an emulsifiable formulation at different conidial concentrations (1.05 9 10 6 , 2.1 9 10 6 and 4.2 9 10 6 conidia ml -1 ) and sprayed onto leaves 2 weeks after artificial pest inoculation. Two sprays were performed, with an interval of one week from one spray to another, and T. urticae population counts (both motile and egg stages) were made on plant leaves 7 days after each spray. Bb conidia in Break-thru Ò were more efficacious than conidia in emulsifiable formulation. With the highest rate of conidia (4.2 9 10 6 conidia ml -1 ), mortality of adult mites ranged from 60 ± 4.2 (mean ± SE) to 85.7 ± 4.3% in the Break-thru Ò suspension and 39.4 ± 7 to 61.3 ± 6% in the oil emulsion. Leaf damage index was also substantially reduced from 70% in the unsprayed control to 40% by the application of Bb conidia at the highest rate with Break-thru Ò . Break-thru Ò can be combined with Bb in the integrated management of T. urticae and Isolate R444 is a promising candidate for the control of the pest.

The efficacy of the fungus Metarhizium anisopliae to control ticks has been shown in several in vitro experiments. However, few studies have been undertaken in field conditions in order to demonstrate the applicability of its use as a biological control of ticks and its combination with chemical acaricides. The aim of the present study was to evaluate the efficacy of M. anisopliae to control an acaricide-resistant strain of Rhipicephalus microplus under laboratory and field conditions. First, the compatibility of M. anisopliae strain (TIS-BR03) with commercial acaricides and its potential to control the cattle tick were evaluated in vitro. In general, acaricide treatments had mild effects on fungus viability. In the field experiment, the median of treatment efficacy with acaricide only, M. anisopliae only and combination of M. anisopliae with acaricide were 71.1%, 56.3% and 97.9%, respectively. There is no statistical difference between groups treated with M. anisopliae and acaricide alone. Thus, in this work we have demonstrated the applicability of M. anisopliae use associated or not with chemical acaricides on field conditions in order to control an acaricide-resistant strain of the cattle tick R. microplus.

Varroa (Varroa destuctor Anderson and Trueman) populations in honey bee (Apis mellifera L.) colonies might be kept at low levels by well-timed miticide applications. HopGuard Ò (HG) that contains beta plant acids as the active ingredient was used to reduce mite populations. Schedules for applications of the miticide that could maintain low mite levels were tested in hives started from either package bees or splits of larger colonies. The schedules were developed based on defined parameters for efficacy of the miticide and predictions of varroa population growth generated from a mathematical model of honey bee colony-varroa population dynamics. Colonies started from package bees and treated with HG in the package only or with subsequent HG treatments in the summer had 1.2-2.

The development of new acaricides is a long and very expensive process. Worryingly, there is increasing resistance to available acaricides worldwide leading to the real possibility that our dwindling supply of effective acaricides will be exhausted unless action is taken to increase the number of new acaricidal products and reduce the rate of resistance development. In 1995, eight major animal health pharmaceutical companies formed the Veterinary Parasite Resistance Group (VPRG) to act as an expert consultative group to guide the FAO in resistance management and collaborate in the prudent use of acaricides. In this paper, members of the VPRG discuss the problems and processes in acaricide development, resistance in the field to commonly used acaricides and the different considerations when targeting the cattle and pet market, and give their view of the future for tick control from the perspective of the animal health industry.

Norval R.A.I., Perry, B.D., Meltzer, M.I., Kruska. R. and Booth, T.H., 1994. Factors affecting the distributions of the ticks Amblyomnm hebraeurn and A. variegaturn in Zimbabwe: implications of reduced acaricide usage. Exp. Appl. Acarol., 18: 383--407.

Dispersal behaviors of phytoseiid and tetranychid mites are key factors in understanding predator-prey dynamics and biological control of pest mites at different spatial levels in agricultural and natural ecosystems. In this review, ambulatory and aerial dispersal of both mite groups are discussed at spatial levels of leaf, plant, crop and region. Emphasis is on dispersal of phytoseiids, and specifically, the specialist-predator, Neoseiulusfallacis (Garman), and two-spotted spider mite prey, Tetranychus urticae (Koch). Dispersal aspects that are discussed are ambulation on a leaf; plant or in a prey patch; aerial dispersal between plants; behavior and aerodynamics of aerial take-off; modeling vs. monitoring of dispersal distance; fates of dispersing mites that land on soil substrates; plants as take-off platforms and landing targets for dispersers; and regional dispersal patterns and integrated mite management.

Sheep scab, caused by Psoroptes ovis, is a severe and debilitating disease that can be treated and controlled by the use of acaricidal dips or the use of broad-spectrum avermectins. In Switzerland, control measures are state regulated. In particular, sheep should be routinely treated with ectocide dips or avermectin injections before they are moved onto common alpine pasture in late spring. However, a substantial part of the sheep population remains untreated and represents a potential reservoir for the mite population. Untreated sheep that are not moved to alpine pasture may infest treated sheep when flocks are reassembled in autumn. In an attempt to identify infested sheep, all flocks in the Canton of Schwyz (Switzerland) were serologically tested in 2001 and in 2002 (587 and 565 flocks, respectively). In 2003, a representative number (182 of the 531 flocks) was again investigated. Seropositive flocks were treated with doramectin (0.3 mg kg À1 body weight, intramuscularly) from 2001 to 2003. In spring 2002, no chemo-methaphylaxis was given to seronegative flocks before movement onto common alpine pastures. Of the 587 flocks surveyed in spring 2001, 34 were seropositive (5.8%). These consisted of 21 infested with P. ovis, 1 with P. cuniculi, 4 with Chorioptes spp. and 8 of seropositivity of unknown origin; there was a decrease of seropositive flocks in spring 2002 (4.4%) with 15, 0, 2 and 8, respectively. Of the 182 flocks surveyed in spring 2003, just 4 flocks (2.2%) were seropositive. All the seropositive reactions in these flocks were the result of Chorioptes spp. infestations.

The aim of this study was to test the effectiveness of physically acting substances (oils and silicas) and plant preparations for the control of the poultry red mite Dermanyssus gallinae (De Geer 1778). Reproduction and survival of fed D. gallinae females were evaluated in vitro for a total of 168 h using the “area under the survival curve” (AUC) to compare survival of the mites between treatments. Four oils (two plant oils, one petroleum spray oil and diesel), one soap, three silicas (one synthetic amorphous silica, one diatomaceous earth (DE) and one DE with 2% pyrethrum extract) and seven plant preparations (derived from Chrysanthemum cineariaefolium, Allium sativum, Tanacetum vulgare, Yucca schidigera, Quillaja saponaria, Dryopteris filix-mas, and Thuja occidentalis) were tested at various concentrations. All the oils, diesel and soap significantly reduced D. gallinae survival. All silicas tested inhibited reproduction. DE significantly reduced mite survival, but amorphous silica was less effective in vitro. Except for pure A. sativum juice and the highest concentration of C. cineariaefolium extract, the plant preparations tested resulted in statistically insignificant control of D. gallinae.

Rhipicephalus microplus, known as the cattle tick, causes serious economic losses in the Brazilian cattle industry each year. Traditional parasite control is primarily based on the use of chemical acaricides, which unfortunately have many negative side effects. Biological control is seen as a promising alternative to chemical acaricide use. This study evaluates the entomopathogenic fungus Lecanicillium lecanii for effectiveness in controlling engorged females, eggs, and larvae of R. microplus. Conidial formulations of L. lecanii, isolate CG 420, were prepared in both oil (15% mineral oil) and aqueous suspensions. Ticks were immersed in a 1 ml oil-based conidial suspension at 1 × 10 8 conidia ml −1 or one of several aqueous conidial suspensions at 1 × 10 5 , 10 6 , 10 7 or 10 8 conidia ml −1 . The control groups were immersed in water or oil solutions with no conidia. Treatments with aqueous conidial suspensions were conducted with 10 ticks per group (1 × 10 5 , 10 6 , 10 7 , 10 8 conidia ml −1 or control) whereas the oil treatments used 30 ticks per group (1 × 10 8 conidia ml −1 or control). Bioassays were repeated twice on different days with different batches of conidia. After treatment, the biological parameters of engorged females were evaluated, while eggs and larvae were evaluated taking into consideration hatchability and mortality, respectively. The results indicate that L. lecanii has the potential to control engorged females, eggs and larvae of R. microplus. Better results were observed when conidial oil-based suspension was used. In general, engorged females treated with 1 × 10 8 conidia ml −1 oil suspensions died before laying eggs, resulting in 97.6% of tick control. As far as we know, this is the first report of the effects of L. lecanii on R. microplus tick.

Parasitic Tropilaelaps (Delfinado and Baker) mites are a damaging pest of European honey bees (Apis mellifera L.) in Asia. These mites represent a significant threat if introduced to other regions of the world, warranting implementation of Tropilaelaps mite surveillance in uninfested regions. Current Tropilaelaps mite-detection methods are unsuitable for efficient large scale screening. We developed and tested a new bump technique that consists of firmly rapping a honey bee brood frame over a collecting pan. Our method was easier to implement than current detection tests, reduced time spent in each apiary, and minimized brood destruction. This feasibility increase overcomes the test's decreased rate of detecting infested colonies (sensitivity; 36.3% for the bump test, 54.2% and 56.7% for the two most sensitive methods currently used in Asia). Considering this sensitivity, we suggest that screening programs sample seven colonies per apiary (independent of apiary size) and 312 ran...

Table 2. Proprietary house-dust mite acaricides and other anti-allergen products, including data oii non-clinical field trials of acaricidal/antiallergen efficacy Trade name and manufacturer/distributor Active ingredient mode of action and concentration Form, dosage, frequency of use Efficacy data from field trials Acarosan (Allergopharma,

East Coast fever (ECF) causes considerable mortality and production losses in the Tanzania smallholder dairy sector and limits the introduction of improved dairy breeds in areas where the disease is present. The infection and treatment method (ITM) was adopted by smallholder dairy farms for ECF immunisation in Hanang and Handeni districts of Tanzania. This study recorded incidence rates for ECF and other tick-borne diseases (TBDs) for ECFimmunised and non-immunised cattle between 1997 and 2000. Approximately 80% of smallholder households from both sites (n=167) participated in this longitudinal study, with immunisations carried out at the request of the livestock owners. Efficacy of ITM for preventing ECF cases in these crossbred dairy cattle was estimated at 97.6%, while that for preventing ECF deaths was 97.9%. One percent of the cattle developed clinical ECF as a result of immunisation. Since ECF immunisation permits a reduction in acaricide use, an increase in other TBDs is a potential concern. Sixty-three percent of farmers continued to use the same acaricide after immunisation, with 80% of these reducing the frequency of applications. Overall, 78% of farmers increased the acaricide application interval after immunisation beyond that recommended by the manufacturer, resulting in annual savings in the region of USD 4.77 per animal. No statistical difference was observed between the immunised and non-immunised animals in the incidence of non-ECF TBDs. However, immunised animals that succumbed to these diseases showed fewer case fatalities. ITM would therefore appear to be a suitable method for ECF control in Tanzania's smallholder dairy sector.

The present study evaluated, for the first time, the effect of the commercial formulation Metarril(®) SP Organic of Metarhizium anisopliae plus 10% mineral oil to control Rhipicephalus microplus in a pen study. Three groups were formed with six animals each: the first group was exposed to Metarril(®) plus 10% mineral oil and 1% Tween 80; the second group was exposed to sterile distilled water, mineral oil and Tween 80 (oil control group); and the third group received no treatment (control group). The fungal formulation contained 1 × 10(8)conidiaml(-1). Each animal was sprayed with 3L of formulation. Fallen ticks were counted daily and a sample of 20 engorged females per day was incubated for assessment of biological parameters. Throughout the study period, Metarril(®) oil-based formulation showed an efficacy ranging from 19.20% to 67.39% in comparison with the control group; and from 8.18% to 61.38% in comparison with the oil control group. The average efficacy of Metarril(®) oil-ba...

The toxic effects of the extracts of Allium sativum (Garlic) were evaluated against adults of Hyalomma marginatum rufipes and Rhipicephalus pulchellus using three types (Types A, B and C) of contact toxicity bioassays. A. sativum bulbs were extracted with acetone, ethanol and dichloromethane (DCM) solvents. Among these three solvents, it is the DCM extract of A. sativum that appears to have anti-tick activity. In the Type A contact toxicity bioassay, DCM extracts of A. sativum demonstrated a high acaricidal bioactivity against H. m. rufipes with 100 % of ticks killed in less than an hour, and toxicity persisted to the second day. A weak acaricidal activity of aqueous extracts of A. sativum was observed in the Type B contact toxicity bioassay. In the Type C contact toxicity bioassay, a concentration of 24 % w/v of DCM extracts of garlic in sunflower oil (Helianthus annuus) had killed 100% of H. m. rufipes (LC50= 5.9 % w/v) and R. pulchellus (LC50 = 10.3 % w/v) by 24 hours post-treatm...

African swine fever (ASF) is a devastating haemorrhagic fever of pigs that causes up to 100% mortality, for which there is no vaccine. It is caused by a unique DNA virus that is maintained in an ancient cycle between warthogs and argasid ticks, making it the only known DNA arbovirus. ASF has a high potential for transboundary spread, and has twice been transported from Africa to other continents--Europe and subsequently the Caribbean and Brazil (1957, 1959) and the Caucasus (2007). It is also a devastating constraint for pig production in Africa. Research at Onderstepoort Veterinary Institute has made and is making important contributions to knowledge of this disease, focusing on the cycle in warthogs and tampans and transmission from that cycle to domestic pigs, resistance to its effects in domestic pigs, and the molecular genetic characterisation and epidemiology of the virus.

When ticks were sealed in nylon tetrapacks and infected with the entomogenous fungi, Beauveria bassiana and Metarizium anisopliae and maintained in potted grass in the field, the fungal oil formulations (10(9) conidia per ml) induced 100% mortality in larvae of Rhipicephalus appendiculatus and Amblyomma variegatum, whereas mortalities in nymphs varied between 80-100% and in adults 80-90%. The aqueous formulations (10(9) conidia per ml) induced mortalities of 40-50% and reductions in egg hatchability of 68% (B. bassiana) and 48% (M. anisopliae) when sprayed on Boophilus decoloratus engorging on cattle. The strains of B. bassiana and M. anisopliae isolated from naturally infected ticks were also found to induce high mortalities in both R. appendiculatus and A. variegatum in tetrapacks placed in potted grass. Both aqueous and oil-based formulations were found to be effective, although the latter induced higher mortalities. These fungal strains in aqueous formulation (10(8) conidia per ...

The majority of asthmatic patients are atopic humidity is too low to support mite popu--that is, they have IgE mediated sensitivity lations. Mite sensitive asthmatic children had to common inhalant allergens. Exposure and a progressive reduction in non-specific BHR sensitisation to allergens from the house dust when taken from their homes in Holland mite is established as an important risk factor to the mite-free environment of Davos, for asthma in most parts of the world. 1-24 In Switzerland. 38 39 Similarly, a progressive readdition, several recent studies have provided duction in asthma symptoms occurred in chilevidence of the importance of exposure to other dren admitted to the residential home at indoor allergens, particularly those from Misurina (altitude 1756 m). 40 Further studies cats, dogs, and cockroaches. [25] The rate of from Misurina reported a significant decrease sensitisation to mites is directly related to expoin mite allergen-induced basophil histamine sure, 30 whilst conversion from sensitisation to release, mite-specific serum IgE level, and non-sensitisation may occur in indoor enmethacholine BHR with reversal of this trend vironments with low allergen levels. after 15 days of allergen re-exposure at sea The severity of asthma is also related to level. 41 Peroni et al found a significant reduction allergen exposure. 32-35 Objective indices of in total and mite-specific serum IgE and allerasthma severity such as bronchial hypergen-induced BHR after three and nine months reactivity (BHR), forced expiratory volume in at Misurina. These results suggest that avoidone second (FEV 1 ), and variability in peak ance of mite allergen leads to a decrease in expiratory flow rate (PEFR) in patients sensairway inflammation with consequent imitised to dust mites correlate with the level of provement in non-specific BHR and sympmite allergens in their beds. 32 Peat et al found toms, and that re-exposure results in a rapid a similar prevalence of sensitivity to mites in relapse. The high altitude studies were not children living in areas with two different levels controlled and there is a possibility that avoidof exposure to mites but BHR was more severe ance of other domestic factors such as exposure in sensitised children living in the area with the to pets or environmental tobacco smoke conhighest mite levels.

Traps have been used extensively to provide early warning of hidden pest infestations. To date, however, there is only one type of trap on the market in the U.K. for storage mites, namely the BT mite trap, or monitor. Laboratory studies have shown that under the test conditions (20°C, 65% RH) the BT trap is effective at detecting mites for at least 10 days for all three species tested: Lepidoglyphus destructor, Tyrophagus longior and Acarus siro. Further tests showed that all three species reached a trap at a distance of approximately 80 cm in a 24 h period. In experiments using 100 mites of each species, and regardless of either temperature (15 or 20°C) or relative humidity (65 or 80% RH), the most abundant species in the traps was T. longior, followed by A. siro then L. destructor. Trap catches were highest at 20°C and 65% RH. Temperature had a greater effect on mite numbers than humidity. Tests using different densities of each mite species showed that the number of L. destructor found in/on the trap was significantly reduced when either of the other two species was dominant. It would appear that there is an interaction between L. destructor and the other two mite species which affects relative numbers found within the trap.

The aim of the present study was to evaluate the effect of Metarhizium anisopliae to control Rhipicephalus microplus under laboratory and field conditions (larvae on vegetation) in the Mexican tropics. In the laboratory study, Ma34, Ma14 and a mixture of Ma34 + Ma14 strains of M. anisopliae were evaluated for their control of the adult and larval stages of R. microplus, using the adult and larval immersion test respectively. The reproductive efficiency index of engorged females was determined in the treated and control groups. In the adults, the Ma34 and MA14 strains both produced an efficacy of 100% on engorged females at 1 × 10 8 , 1 × 10 7 and 1 × 10 6 conidia/ml; however, only Ma34 killed 100% at 1 × 10 6 conidia/ml dose. The mixture of both strains (Ma34 + Ma14) produced an efficacy of 100% on engorged females at 1 × 10 8 conidia/ml. R. microplus engorged females treated with Ma34 and a mixture of strains Ma34 and Ma14 reduced egg oviposition by 55.5% and 39.1% respectively compared to treated controls (P < 0.001). In the larval evaluation, Ma14 produced an efficacy of 45-62%; however, Ma34 + Ma14 increased the efficacy reaching 90% (1 × 10 8 conidia/ml concentrations, P < 0.05). In the field study, twelve 9 m 2 plots with vegetation were artificially infested with R. microplus larvae. Six plots were used as control and six as test areas. The treated plots received the Ma34 + Ma14 (1 × 10 8 conidia/ml) by manual scattering at 0, 14 and 28 days post-treatment (PT). The number of larvae in the treated and control group was determined at 0, 7, 14, 21, 28 and 35 days PT by the tick drag method. This field study was carried out in two different seasons (January-March, wet, April-May, dry). In the wet season trial the efficacy of M. anisopliae to control R. microplus was 67.7% and 100% in the dry season trial .In conclusion, the mixture of Ma34 and Ma14 strains of M. anisopliae showed a high efficacy to control both larval and adult stages of R. microplus under laboratory conditions, and in field conditions these strains were efficient to control larval stages on vegetation. (R.I. Rodriguez-Vivas). it transmits (e.g. Babesia bovis, Babesia bigemina and Anaplasma marginale) and the parasitism itself, which causes reduction in milk yield, calf production and high costs in tick control .

Lavandula angustifolia is a well known herbal medicine with a variety of useful properties, including its acaricidal effect. This experiment was carried out to study the bioacaricidal activity of L. angustifolia essential oil (EO) against engorged Rhipicephalus (Boophilus) annulatus (Acari; Ixodidae) females. For this purpose six serial concentrations (0.5, 1.0, 2.0, 4.0, 6.0 and 8.0% w/v) of L. angustifolia EO were used. There was considerable mortality in concentrations more than 4.0% although there were no differences between 6.0 and 8.0% in all measured criteria. The mortality rate 24 h after inoculation was 73.26 and 100% in groups treated with 4.0 and 8.0% EO, respectively. Lavender EO also reduced tick egg weight in a concentration-dependent manner. The amount of eggs produced varied from 0.12 g (at 0.5% EO) to 0.00 g (at 8.0% EO) but did not differ statistically from the control. L. angustifolia EO caused 100% failure in egg laying at 6.0 and 8.0% whereas this value in the control group was zero. A positive correlation between L. angustifolia EO concentration and tick control, assessed by relative mortality rate and egg-laying weight, was observed by the EO LC/EC 50 , which, when calculated using the Probit test, was 2.76-fold higher than the control. Lavender is a promising acaricidal against R. (B.) annulatus in vitro.

C.A. Ángel-Sahagún et al. / Veterinary Parasitology 170 (2010) 278-286 279 7-day-old larvae. In the laboratory, all M. anisopliae isolates infected larvae with a mortality range between 2 and 100%; also, 13 of 20 I. fumosorosea isolates caused mortality rates between 7 and 94%. In the first field trial, 14 days post-application, conidial formulations in Celite and wheat bran caused 67.8 and 94.2% population reduction, respectively. In the second trial, the Tween formulation caused the highest larval reduction, reaching up to 61% (28 days post-application). Wheat bran formulation caused 58.3% larval reduction (21 days post-application) and was one of the most effective. The carriers and emulsifiers have a large impact on the effectiveness of conidial formulations.