The cattle tick Rhipicephalus microplus is an ectoparasite with high economic importance to bovine culture, mainly in tropical and subtropical regions. The resistance of the tick from the commercial acaricides has hindered its control, thus motivating the search for new strategies. The purpose of this study was to perform a critical review about the main molecular targets of R. microplus that are useful for the discovery of new acaricides. Bibliographic search was conducted in the databases PubMed, ScienceDirect and CAB Direct, using the following descriptors: ‘Rhipicephalus microplus’, ‘Boophilus microplus’, ‘molecular targets’ and ‘action’, published between 2010 and 2021. Out of the 212 publications identified, 17 articles were selected for study inclusion. This review described 14 molecular targets and among these 4 are targets from commercial acaricides. Most of them are enzymes to catalyse important reactions to tick survival, related to energetic metabolism, mechanisms of biotransformation and neurotransmission. The data will be helpful in the development of new more effective and selective acaricides.

Poultry red mite (Dermanyssus gallinae), the haematophagous pest of egg laying hens, is an important problem in poultry production in many parts of the world. Control has typically relied on synthetic acaricides in spite of advancements in immunological, biotechnological and genetic approaches. However, the repeated long term use of these compounds has resulted in the development of drug resistant populations of poultry mites, therefore, the availability of effective acaricides is diminishing rapidly. Due to this, there is need for the continuous availability of new chemical acaricides to replace the older types, however the development and registration of new acaricides is a long expensive process, therefore, preserving and maintaining the effectiveness of available acaricides is essential.

This review has two parts; the first is to provide the basic understanding of acaricide resistance in D. gallinae while the second part provides more detailed knowledge about the management of resistance to preserve the efficacy of available acaricides.

Although widely used, the term repellency needs to be employed with care when applied to ticks and other periodic or permanent ectoparasites. Repellency has classically been used to describe the effects of a substance that causes a flying arthropod to make oriented movements away from its source. However, for crawling arthropods such as ticks, the term commonly subsumes a range of effects that include arthropod irritation and consequent avoiding or leaving the host, failing to attach, to bite, or to feed. The objective of the present article is to highlight the need for clarity, to propose consensus descriptions and methods for the evaluation of various effects on ticks caused by chemical substances.

We studied the mite complex—consisting of Tetranychus cinnabarinus (Boisduval), T. urticae (Koch) and Aculops spp.—on three varieties of carnation (Finesse, Optima and White Barbara) in a flower farm in Kenya. Over a period of 24 months, those carnations established in a soilless substrate (pumice in gunny bags) harboured on average less than five mites per leaf as compared to over 20 per leaf on plants established on bare soils. This was the case whether the crop was judiciously or prolifically sprayed with acaricides. The study further established that the economic gain was the same when lower volumes of pesticides were used, whether sprayed judiciously or prolifically. The variety White Barbara generally harboured higher mite numbers than Finesse or Optima. Furthermore, there were fewer rejections, and higher market value when plants were established on pumice substrate compared to bare soils. The study further showed that planting in pumice holds promise for mite control in flower farms. Furthermore, predatory natural enemies of the pest mites, including phytoseiid mites and Orius spp., were conserved in plots where pumice was used with minimum spray.

In Kenya, there are at least seven distinct tick-borne diseases (the ileriosis, anaplasmosis, babesiosis, heartwater, Nairobi sheep disease, sweating sickness and erhlichiosis in dogs). Theileriosis causes major economic losses arising from deaths of infected cattle.

Control of these diseases is almost exclusively by the application of chemical acaricides to cattle. Use of acaricides is regulated and only those passing field tests are permitted to be marketed in Kenya. Field trials on immunization against East Coast fever (ECF) by infection and treatment are still continuing. Chemotherapy treatment is also available but quite expensive.

The Veterinary Department continuously evaluates acaricides which have been documented to have activity against ticks. These acaricides have been grouped into four groups ranging from organophosphorus compounds in Group I to synthetic pyrethroids in Group IV. To-date Groups III and IV acaricides are kept as reserve, although amitraz in Group III can be used on a limited scale on privately owned farms.

The use of synthetic acaricides in tick control is increasingly becoming more expensive. As a result, a lot of Africa's resource-poor farmers are failing to dip their cattle regularly. Natural products offer these farmers a cheaper alternative to synthetic acaricides. There is indeed a great potential for the use of Africa's huge natural resources, the plants to develop sources of acaricides to reduce the cost of tick control being locally available and potentially being able to be produced and used by farmers themselves or by cottage industries. It is, however, necessary that research centres such as ICIPE encourage the development of systematic research on natural products in order to bring about the Tephrosia vogelii leaf extracts observed to be highly toxic to one-, two- and three-host ticks and cattle sprayed with the extract had a residual protection period of 10 days from re-infestation by ticks.

An account of the history of tick control in Uganda is given. It is presented in three phases. Phase one covers the years 1935–1970, being a period of relative stability, while phases two and three cover the periods 1971–1985, characterized by wars and political instability, and 1986 to-date, years of calm and national rehabilitation, respectively.

Mention is also made on the future strategies for the control of ticks based on new technologies and earlier experience.