Boophilus microplus is Brazil's outstanding livestock ectoparasitic pest (annual losses, US$ 1B), affecting, to varying extents, all its States, with a national herd of some 130 M cattle. The country's 8.5 M sq km and 23,000 km of land frontier with 10 tick infested countries complicate any concepts of national campaigns. Whereas Brazil is increasingly climatically suitable for B. microplus from south (three generations annually) to central (four) to north (potentially up to five), direct problems caused are incidentally decreased due to greater use of Bos indicus cattle at lower stocking rates; five tick population survival mechanisms are suggested. Voluntary, empirical chemical tick control remains the tradition, with little government involvement. Formamidine and synthetic pyrethroid acaricides dominate the market, due to former tick resistance to arsenicals, organochlorines and organophosphates, and market forces. Plunge dips, various sprayers, and “pour-on” formulations are used; first suspicions of tick resistance to synthetic pyrethroids have been reported. Various ecologically based “improved” tick control schemes produced promising results experimentally, but require a complementary vaccine against babesiosis/anaplasmosis before wide recommendation. Intensive use of synthetic pyrethroid acaricides has created tick-borne diseases and heightened demand for a live, frozen “vaccine”, in its pre-commercialization phase in Brazil. A strategic research and development approach has been adopted for widespread improvement to cattle ticks and tick-borne disease control in Brazil.

The biology of Bemisia afer (Prisner & Hosny) reared in clip cages on leaves of 15 varieties of cassava, Manihotesculenta (Crantz)(Euphorbiaceae) was studied under field conditions during the cold months of June–August and during the warm months of September–October. Both variety and time of the year significantly affected the developmental period, the rate of population increase and the mortality.

The longest mean developmental period (59.5 days) occurred on the MH108 leaves during the cold months (at 20°C and 62.9% r.h.), while the shortest (27.1 days) was on the Kithekere variety during the warm months (at 25°C and 53% r.h.).

The pest population increased most rapidly on MH84 (at 5.4 eggs per female per day) and slowest on the Nigerian 3057/1 (at 0.9 eggs per female per day). The mortality of the pest indicated that Chitembwere had the greatest killing power (K = 2.555) and Nigerian 3057/1 had the least (K = 0.0760).

The combined use of the developmental periods, rate of population Increase and mortality indicated that Gomani was the most resistant while Kithekere was the least resistant variety to B. afer. Other varieties with high resistance properties included MH108, Chitembwere and Mbundumali. Of the three biological characteristics used, the developmental period was the most powerful while the rate of population increase was the least.

Pubescence of a cassava variety was only weakly associated with resistance to B. afer (r = 0.48) suggesting that other factors are more responsible for resistance to this pest than hairiness.

A brief description is given of the tick species, their distribution, the diseases they transmit and the control methods used in Botswana. Most of the country is unsuitable for the permanent establishment of the more important ticks so that the diseases they transmit are confined mainly to the eastern part of the country. Among the tick-borne diseases, cowdriosis is the most important although sporadic cases of anaplasmosis and babesiosis also occur. Canine erhlichiosis is established in the urban areas. The presence of theileriosis as a clinical disease has yet to confirmed in Botswana.

A situation report on the Ixodoidea infesting livestock in India is presented. Of the nearly 120 tick species known from this country, information regarding the hosts and distribution of 46 ixodid species belonging to eight genera and six argasid species belonging to three genera, parasitizing livestock has been provided. The ecology and disease relationship of the economically more important species have been reviewed. Notwithstanding the rich tick fauna, the native cattle seldom carry excessive tick burdens. Control is greatly facilitated by the high degree of natural resistance possessed by indigenous cattle, zebu. Chemical acaricides are the maincomponent of control strategies which are largely aimed at protecting the at-risk exotic and crossbred animals from ticks and the diseases transmitted by them. Exploitation of immunity and possibly some biological control may be integrated with the use of chemicals in future.

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.

Nineteen different tick species have been identified in Western Ethiopia. The most important ticks belong to the genera Amblyomma, Boophilus, Hyalomma and Rhipicephalus, while the major cattle tick-borne diseases are anaplasmosis, babesiosis and theileriosis, T. mutans.

Dipping, hand spraying and spray races for ticks are only practised in the state dairy farms where cross-bred cattle are kept. The main acaricide in use is the chlorinated hydrocarbon, toxaphene. Flumethrin bayticol pour-on is now being used to a limited degree on dairy cattle. Traditional tick control methods which include hand-picking and the application of plant preparations are widely used on indigenous cattle.

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.