The possibility of controlling 0. moubata by feeding hosts on certain chemicals was explored by De Meillon (1946). Fifty mgm. of pure gamma isomer of gammexane were mixed with agar and water and fed to rabbits four or five times. The ticks fed only briefly and showed either incoordination or death afterwards. The domesticated tampan's predilection for human blood obviously limits the application of this interesting approach. moubata is also susceptible to arsenic compounds in the blood of animals. Injections of neoarsphenamine have been used in rabbits for this purpose (De Meillon, Thorp, and Hardy 1948). The failure of 2:3 dimercaptopropanal (British anti-lewisite) to alter the toxicity of neoars phenamine was described by Thorp, De Meillon, and Hardy (1948). In testing insect and tick mortality when exposed to dry insecticidal film, Busvine and Barnes (1948) found that 0. moubata nymphs are resistant to DDT but susceptible to gammexane and pyrethrins. Busvine and Nash (1953) also determined that films of oil solutions are better than dry films for testing insecticides because they give a sharper dose/kill relation. The value of certain derivatives of phenol and naphthalene as soil-fumigants in hut floors has been suggested (Robinson 1944A). Derris powder failed to affect nymphal 0. moubata in Russian laboratory tests (Mironov, Nabokov, and Kachalova 1946). Pyrethrum sprays and dusts are highly toxic (Robinson 1942C,D,1943B,1944B) but field tests have not been undertaken, probably due to high cost of pyrethrum and effectiveness of cheaper BHC. Sulfur dioxide or cyanide fumigation has little effect on 0. moubata, and sprays of kerosene and formalin are not success ful (Hopkins and Chorley 1940). A spray consisting of 30 cc. turpentine, 50 cc. twenty-five percent alcohol, 5 cc. kerosene and a little white soap was suggested by these authors, though it is expensive and troublesome to prepare. Their best recommendation was a coarse, roughly filtered spray consisting of 11⁄2 pounds of paradichlorobenzene in one gallon of kerosene applied under high pressure at the rate of twelve to fourteen gallons per two thousand square feet of surface (also reported by Hargreaves 1936). The ovicidal value of concentrated vapors of chloroform, sulfurous acid, ammonium sulfide, ethel dixanthogen, BHC, formalin, and phenol has been reported (Enigk and Grittner 1953). A report of the resistance of 0. moubata to various sheep dips (Blacklock 1912) is of little contemporary interest. Disinfection of Personal Effects Blankets, bedding, and clothing may be disinfected by exposure in a tight container to a temperature of 82°C. for half an hour (Hopkins and Chorley 1940). Burning In a carefully conducted experiment, Garnham (1926) found, contrary to certain textbook statements, that burning of African huts infested with 0. moubata is an effective means of killing these ticks. He suggested pulling down the straw roofing and piling it inside mud hut walls for burning. This may be the only means of control where the indigenous population does not work for pecuniary gain. Otherwise burning is uneconomical un less the situation is serious. More permanent housing, in which infestation may be controlled or better still prevented, should be substituted whenever possible. Burning infested buildings has long been the indicated control method in many parts of Africa. Flame throwers are sometimes used to good effect where ticks are lodged in shallow cracks in buildings that withstand fire. (1931) obtained control against tampans in nine-inch walls of pigsties by burning brushwood on both sides of them. Burning against only one side and spraying with a ten percent emulsion of paraffin (i.e. kerosene) had failed. Hand-picking Jack A reward of sixpence for every twenty ticks collected on a South African farm yielded 73,000 ticks one year and over half a million in several years. Laborers placed a thin layer of drift manure along the inside walls of their huts and there collected the ticks as they came to hide. Small holes dug inside and outside the doors and filled with drift manure were also found to be favorite hiding places (Annecke and Quin 1952). DISEASE RELATIONS Man (In nature) 0. moubata is the only known tick vector of African tick-borne relapsing fever (Borrelia duttonii) of East, Central, and South Africa. A few cases of this disease have been reported from Equa toria Province in the Sudan. No evidence supports certain pub lished maps showing known extensive distribution of tick-borne relapsing fever in many areas of the Sudan. It should be noted that populations of this tick from burrows of wild animals have not been found infested with spirochetes. It is claimed that some specimens naturally infected with rickettsia, Coxiella burnetii, the causative organism of Q fever, have been found in Ruanda Urundi, and that in Kivu others have been taken infected with an organism referred to as "Bashi virusrickettsia. The etiologic agent of food poisoning, Salmonella enteritidis, has been recovered from this tick in Africa. 0. moubata has not actually been found infected in nature with the pathogenic organisms of any other human disease, but experimental data strongly indicate further research in this respect. Circumstan Tampan bites may cause considerable irritation. tial evidence suggests that persons long victimized by bites of this tick may develop an immunity to them. Fowls 0. moubata is an experimental vector of fowl spirochetosis (Borrelia anserina). It is of negligible importance in transmission of Salmonella bacteria and of Aegyptianella pullorum (a protozoan). The bacterium that causes avian cholera (Pasteurella avicida) survives only a few days in 0. moubata. Experimental Disease Relations Viruses and Rickettsiae The use of O. moubata and other Ornithodoros species for trans porting a number of pathogenic organisms for experimental purposes has been suggested. This species is easily infected with Q fever (Coxiella burnetii) and is capable of transmitting the organism by its bite. A diagnos tic test for Q fever, using 0. moubata for feeding on a suspected host, has been developed. Rickettsia prowazekii, the causative organism of classical typhus, and R. typhi, that of murine typhus, develop in 0. moubata. The former rickettsia can be transmitted transovarially and the latter can be found in eggs and coxal fluid of infected ticks. No multiplication of R. tsutsugamushi, the causative organism of scrub typhus, occurs in 0. moubata; the tick is therefore not a likely vector of this unusually host-specific rickettsia. 0. moubata maintains infection with the virus of Russian spring-summer (Far Eastern) encephalitis. It has also been shown that these ticks can be infected with western equine encephalitis virus. The virus causing murine poliomyelitis (strain Columbia SK) is destroyed or inactivated in blood ingested by the tampan. Yellow fever is not transmissible by this tick. A Congo rickettsia of the boutonneuse fever type (boutonneux-pourpre) remains virulent in ticks fed on infected guinea pigs for two months but not for six months. Bacteria Tularemia (Bacterium tularense) is transmitted by the bite of 0. moubata and is also transovarially transmitted to progeny. Bacillus anthracis, the causative organism of anthrax, is not transmissible and apparently kills the ticks, although it does remain virulent in the tick's body long after death. The etiologic agent of food poisoning, Salmonella enteritidis, has been recovered from this tick in Africa. Spirochetes of Relapsing Fever 0. moubata is capable of harboring and transmitting other Borrelia species besides B. duttonii. This is of considerable interest since in other parts of the world many species of Borrelia are host-specific and tick hosts are spirochete-specific. Spirochetes Other Than Relapsing Fever Weil's disease (Leptospira icterohaemorrhagiae) survives for about forty days in living 0. moubata, remains virulent in the body long after the tick's death, and can be transmitted when infected ticks bite. Filariae Filariae may develop in the body cavity of 0. moubata but transmission appears to be unlikely. Trypanosomes Virulent trypanosomes may remain in the tick's gut for as long as five years, but transmission is apparently impossible and transovarial infection does not occur. Toxoplasmosis It appears that Toxoplasma gondii cannot be transmitted by 0. moubata although the organism survives in the tick for almost two weeks after artificial inoculation. Tropical Ulcer The suggestion has been made that tick bites, such as those of O. moubata, may be initially responsible for tropical ulcer. IDENTIFICATION 0. moubata might be confused only with 0. savignyi in the African fauna. However, since 0, moubata lacks eyes, which in 0. savignyi are present as two pairs of small, round, equal sized, |