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English: Boophilus decoloratus is the most dominant and economically important tick that infests cattle in the central Free State. Very little research on this tick in the central Free State has, however, been conducted. The broad objectives of this study were to investigate aspects of the oviposition and reproduction, tolerance of engorged females to sub-zero temperatures, and microhabitat selection, survival and seasonal abundance of non-parasitic larvae, and the seasonal dynamics of B. decoloratus parasitic on cattle in Botshabelo, central Free State. Engorged B. decoloratus females exposed to 10°C did not lay eggs whereas those kept at 15, 20, 25, and 30°C, respectively laid eggs. The shortest (3.5days) mean pre-oviposition period was recorded at 30°C and 75% RH and the longest (13.2 days) at 15°C and a RH of 35%. The developmental zero temperature for pre-oviposition was calculated at 9.138°e. The oviposition period was more extended at lower temperatures. The shortest mean oviposition period (8 days) was recorded at 30°C and 35% RH. Incubation was also more extended at lower temperatures. The developmental zero temperature for incubation was calculated at 4.73°C. This value was lower than expected and probably due to a smaller sample size or lack of values for eggs incubated between 10 and 15°C. Relative humidity did not affect the oviposition period or the pattern in daily egg production. Peak egg production (533) was reached within five days from the start of oviposition. B. decoloratus females lay average sized eggs. Females weighing more than 200mg produced an average of 11.4 eggs per mg of body mass. The average conversion efficiency index (Cêl) values recorded in this study recorded nutrient index (NI) values were 10-15% less than the recorded values for specific weight classes of B. microplus. Females exposed during May 1998 to naturally fluctuating conditions died during late winter (August) without laying eggs. Eggs which were laid during April and Ma, Afrikaans: Boophilus decoloratus is die mees dominante en ekonomies belangrike bosluis wat beeste in die sentrale Vrystaat besmet. Min navorsing is egter in die verlede op hierdie bosluis in die Vrystaat uitgevoer. Die breë doelstellings van hierdie studie was om aspekte van eierlegging en reproduksie tolleransie van volgesuigde wyfies teen sub-zero temprature en mikrohabitat seleksie, oorlewing en seisoenale voorkoms van nie-parasitiese larwes, en die seisoenale dinamika van B.decoloratus parasities op beeste in Botshabelo te ondersoek. Volgesuigde B.decoloratus wyfies wat aan l O'C blootgestel was het nie eiers gelê nie, terwyl die wat by 15, 20, 25 en 30°C gehou is, wel eiers gelê het. Die kortste (3.5 dae) gemiddelde voor eierleggings tydperk is by 30°C en 75% RH aangeteken, terwyl die langste (13.2dae) by 15°C en 35% RH aangeteken is. Die ontwikkelings zero temperatuur vir voor eierlegging was 9.138°e. Eierlegging het langer geduur by laer temprature. Die kortste (8dae) gemiddelde eierleggingsperiode was by 30°C en 'n 35% RH aangeteken. Inkubasie het ook oor'n meer verlengde tydperk plaasgevind by laer temprature. Die ontwikkelings zero temperatuur vir inkubasie was 4.73°C. Hierdie waarde is laer as wat verwag is en is waarskynlik te wyte aan 'n klein monstergrootte of 'n tekort aan waardes vir eiers wat tussen 10 en 15°C geinkubeer is. Relatiewe humiditeit het nie eierlegging of die daaglikse patroon in die lê van eiers beinvloed nie. Piek eierproduksie (533) is binne vyf dae vanaf die aanvang van eierlegging bereik. B. decoloratus wyfies lê eiers van 'n gemiddelde grootte. Wyfies wat meer as 200mg weeg produseer gemiddeld 11.4 eiers per mg liggaamsmassa. Die gemiddelde omskakelings doeltrefIenheids indeks (CEQ waardes tydens hierdie studie is as 49.36% bereken, wat naby die waardes is wat vir ander Boophilus species bereken is. Die voedings indeks (Nl) waardes wat tydens hierdie studie bereken is was 10-15% minder as die waardes wat vir B. microplus bereken i

English: The behaviour and survival of C. felis are highly dependent on biotic and abiotic factors in the environment and therefore developmental and nutritional requirements demand that eggs must be laid in a environment which provides the suitable microhabitat for C. felis development. Since eggs and larval stages of the cat flea cannot survive major fluctuations in temperature and humidity, sites for development are usually limited. It was found that eggs desiccated at low relative humidities and hatched faster at higher temperatures. The percentage adult emergence also depended on the type of rearing medium on which the larvae fed. The duration of the larval stage increased with a decrease in temperature and eggs exposed to high relative humidity resulted in larger larvae. However, Ci felis populations survive because of a large reproductive capacity of the female and the ability of the pupal stage to survive environmental fluctuations. The pupa is the immature stage that is most resistant to desiccation and it is during this stage that C. felis is able to prolong its life cycle in order to survive unfavourable conditions. The fully developed adult flea can remain quiescent within the cocoon, presumably awaiting proper stimuli for emergence. Optimal conditions for C. felis development were found to be 25±2°C and 75±2% relative humidity. In spite of the many similarities between C. felis and C. canis, a comparative study showed conspicuous differences in the micro-morphology of these two species. Although only small differences were found in the biology of C. felis and C. canis, the host specificity and geographical distribution of the two species varied greatly. C. felis is the most common flea species to attack domestic pets, C. canis is more restricted in distribution. Apart from its association with various diseases and flea allergy dermatitis (FAD), C. felis can also serve as the intermediate host for the dog tapeworm, D. caninum. C. felis become infected wi, Afrikaans: Omdat die gedrag en oorlewing van C. felis afhanklik is van biotiese en abiotiese faktore in die omgewing, moet eiers in 'n omgewing gelê word wat 'n geskikte mikrohabitat voorsien vir C. felis ontwikkeling. Gedurende die studie is gevind dat eiers uitdroog by lae relatiewe humiditeit en vinniger uitbroei onder hoër temperature. Die persentasie volwasse vlooie wat ontpop het, het ook afgehang van die voedingsmedium waarop die larwes gevoed het. Geskikte omgewings vir optimale ontwikkeling is gewoonlik skaars, omdat die eier en larwale stadiums nie groot temperatuur- en humiditeitsfluktuasies kan oorleef nie. Die lengte van die larwale stadium het toegeneem met 'n afname in temperatuur en eiers wat aan hoë relatiewe humiditeite blootgestel is, het groter larwes tot gevolg gehad. C. felis populasies oorleef egter as gevolg van die wyfie se hoë reproduserende vermoë en die weerstandbiedendheid van die papie stadium teen fluktuasies in die omgewing. Van die onvolwasse stadiums is die papie die meeste bestand teen uitdroging en verlenging van die lewensiklus kan tydens dié stadium plaasvind ten einde ongunstige toestande te oorleef. 'n Volledig ontwikkelde volwasse vlooi kan rustend in die kokon bly totdat 'n geskikte stimulus die vlooi stimuleer om te ontpop. Ontwikkeling van C. felis was optimaal by 25±2°C and 75±2% relatiewe humiditeit. Ten spyte van heelwat ooreenkomste tussen C. felis en C. canis, het 'n vergelykende studie ooglopende morfologiese verskille tussen dié twee species aan die lig gebring . ..Hoewel slegs klein verskille in die biologie van C. fe/is en C. canis gevind is, is daar groot verskille in die gasheerspesifisiteit en geografiese verspreiding van die twee spesies. Behalwe dat C. felis met verskeie siektes en allergiese dermatitis geassosieer word, kan die katvlooi ook optree as tussengasheer van die hondelintwurm, D. caninum. C. felis word geïnfekteer met die lintwurm gedurende enige tyd van die larwale stadium wanneer die vlooi larwe, National Research Foundation (NRF)

English: Biting lice are well known ecto-parasites of vertebrates. Most wild and domesticated animals have one or more louse species, living on them. Although lice are a source of irritation to the host, they are not generally considered as economically important because they do not cause much physical damage. The sheep biting louse (Damalinia avis) has, however, been shown to cause losses in wool production and quality. Damalinia limbata are ecto-parasites on Angora goats and can cause the same type of losses to the farmer as the sheep biting louse. Very little research has been done on these lice and their impact on mohair production can therefore not be objectively assessed. The objectives of the current study were to investigate aspects of the biology and distribution of D. limbata and to promote more effective and economical management of these lice on commercial farms. The following were investigated: (1) Aspects of the morphology of D. limbata and D. avis. (2) Environmental temperatures prevalent on the body of Angora goats. (3) The number of nymphal instars of D. limbata. (4) Seasonal changes in the populations of D. limbata. (5) The influence of D. limbata on the body mass of Angora goats and the production and quality of mohair, as well as the efficacy of different control methods. Field experiments were conducted on the farm Preezfontein (29°50'S, 25° 19'E), situated 10 km from the town Fauresmith, about 130 km southwest of Bloemfontein in the south-western Free State. The veld type of this area is defined as 'False Upper Karoo' and falls in the Karoo biorne. The Free State is a summer rainfall region with an average precipitation of 450-500 mm per annum, with hot summers and cold winters and droughts occurring regularly. D. limbata and D. avis were compared using general morphological characters, morphometric measurements of various body regions and placement of dorsal and ventral abdominal sclerites. D. limbata has a more robust appearance than D. avis., Afrikaans: Bytende luise is bekende ektoparasiete van vertebrate. Meeste wilde en mak- of huisdiere het een of meer luisspesie wat hulle parasiteer. Alhoewel die luise 'n bron van irritasie vir die gasheer is, word hulle nie normaalweg as ekonomies belangrik beskou nie, aangesien hulle min fisiese skade veroorsaak. Daar is wel aanduidings dat die bytende skaapluis (Damalinia ovis) verliese in wolproduksie en kwaliteit kan veroorsaak. Damalinia limbata, wat Angora bokke infesteer, kan moontlik dieselfde tipe verliese veroorsaak as D. ovis op skape. Min navorsing is egter nog gedoen op hierdie luise en gevolglik kan die invloed wat hulle moontlik op sybokhaar-produksie en -kwaliteit het nie objektief bepaal word nie. Die doelstellings van hierdie studie was om aspekte van die biologie en verspreiding van D. limbata te ondersoek sowel as die bevordering van effektiewe en ekonomiese bestuur van die luise op plase. Die volgende is ondersoek: (1) Aspekte van D. limbata en D. ovis se morfologie. (2) Die omgewings temperature op die lyf van Angora bokke. (3) Die aantal nimf instars van D. limbata. (4) Die seisoenale veranderings in D. limbata bevolkings. (5) Die invloed van D. limbata op die liggaamsmassa van Angora bokke en die invloed op bokhaarproduksie en - kwaliteit asook die doeltreffendheid van verskillende beheerrnetodes. Veldwerk is op die plaas Preezfontein (29°50'S, 25° 19'E) ongeveer 10 km buite Fauresmith in die suid-wes Vrystaat (ongeveer 130 km suid-wes van Bloemfontein) gedoen. Die veld tipe in hierdie area word beskryf as Skyn Hoër Karoo en val binne die Karoo bioom. Die Vrystaat is 'n somer-reënval gebied met jaarlikse neerslag van ongeveer 450-500 mm. Somers in die gebied is baie warm en die winters koud, met droogtes wat gereeld voorkom. Die algemene morfologiese kenmerke, morfometriese kenmerke en die plasing van dorsale en ventrale abdominale plate van D. limbata en D. ovis is vergelyk. D. limbata vertoon stewiger in vergelyking met D. ovis. Wyfies van

The present study was conducted in the greater Bloemfontein area and focussed on the interaction between ticks and dogs. The sampling localities included Bloemfontein, Botshabelo and Thaba Nchu, and various sub-divisions thereof Rhipicephalus sanguineus and Haemaphysalis leachi, being dog ticks and the expected dominant species, were subject to close scrutiny. The present study was a comparative one which consisted of both field and laboratory work and which was designed to address several objectives. The first objective was to study tick diversity, prevalence and relative density. The second objective was to study the effect of various abiotic factors (temperature, relative humidity and photoperiod) on the development rate and survival of eggs, larvae and nymphs of the two dominant species. The third objective was to examine the influence that social factors (e.g. attitudes of dog owners, socio-economic levels, education and awareness, development levels in terms of infrastructure) have on the relationship between ticks and dogs. The results of the present study indicated that the dogs in the greater Bloemfontien were parasitised by at least nine different species. The species with the highest prevalence (and relative density) were R. sanguineus (73.5% and 27.4) and H. leach; (22.4% and 5.8). Other species constituted less than 1.2% of the total sample and were regarded as being incidental. These species included Boophilus decoloratus, Hyalomma truncatum, Rhipicephalus evertsi evertsi, Ixodes rubicundus, Rhipicephalus sp., Rhipicephalus gertrudae and Rhipicephalus follis. There was a clear distinction between the different attachment sites of the two dominant species and both species displayed seasonal patterns. Greater numbers of the two dominant species were found during the warm summer months and very few during the cold winter months. Daily egg production of the two dominant species was similar to that of other ixodid ticks while the pre-oviposition and incubat

English: Sheep scab, which is caused by the mite Psoroptes ovis, has been and is still today an impediment to sheep husbandry in many countries throughout the world. Despite the economic impact, sheep scab remains a serious veterinary problem in South Africa. The broad objectives of this study were to determine the adverse effects of P. ovis on the host, with special reference to Merino and Dorper sheep, and to examine various possible foci of infestation and host specificity. Furthermore, the effects of abiotic factors (relative humidity and temperature) on the off-host survival of P. ovis were determined. The nature and extent of sheep scab in small scale, predominantly black farming communities, were assessed and compared to commercial predominantly white farming communities. The results revealed the following: With the exception of neutrophils, haematological values remained within the normal range for infested Merino and Dorper sheep, during a 14 week assessment period. For both sheep breeds the albumin and globulin values were higher than the normal range during the entire 14 week observation period. Both sheep breeds displayed a slight decrease in albumin values and a slight increase in globulin values. At the termination of a 16 week assessment period, uninfested control Merino sheep gained a mean ·body mass of 3.44 kg which represented a Il. 60% increase in body mass, compared to the mean body mass decrease (6.4 kg) of infested Merino sheep. This represented a 23.43% decrease in body mass. The mean body mass of the infested Dorper sheep increased over the 16 week period by 4.56 kg (15.11%) compared to the 5.88 kg (18.28%) of the uninfested control Dorper sheep. Comparative studies on the rate of sheep scab lesion development indicated that there were profound differences between sheep breed and season. During the summer assessment of 1997 the mean lesion size on the Merino sheep expanded from 1.0 cm2 at two weeks post infestation to 342.2 cm2 at eight weeks, Afrikaans: Skaapbrandsiek wat deur die myt Psoroptes ovis veroorsaak word was van die vroegste tye reeds, en is nog steeds, 'n belemmering vir die skaapboerdery bedryf Ten spyte van die ekonomiese impak is skaapbrandsiek ook 'n ernstige veeartsenykundige probleem in Suid Afrika. Die oorhoofse doelstellings van hierdie studie was om ondersoek in te stel na die nadelige effek van P. ovis op die gasheer, om die moontlike infestasie bronne en ook gasheer spesifisiteit te ondersoek. Voorts is die effek van abiotiese faktore (relatiewe humiditeit en temperatuur) op die oorlewing van P. ovis weg van die gasheer vasgestel. Die aard en omvang van skaapbrandsiek in klein, oorwegend swart boerdery gemeenskappe was vasgestel deur fisiese ondersoek en vraelysopnames is ook gemaak en vergelyk met soortgelyke vraelysopnames in kommersiële, oorwegend wit boerdery gemeenskappe. Uit die resultate het die volgende aan die lig gekom: Met die uitsondering van neutrofiele, was die hematologiese waardes, gedurende 'n 14 week observasie tydperk, vir beide Merino en Dorperskape binne die normale perke. Vir beide skaaprasse was die albumien and globulien waardes deurgaans, gedurende die observasie tydperk, bokant die normale vlakke. Beide skaaprasse het 'n effense afname in albumien waardes, en 'n effense toename in globulien waardes getoon. Na afloop van 'n 16 week. waarnemingstydperk, het ongeïnfesteerde kontrole Merinoskape 'n gemiddelde liggaamsmassa toename van 3.44 kg (11.60%) getoon, vergeleke met 'n gemiddelde liggaamsmassa afname van 6.4 kg (23.43%) vir geïnfesteerde Merinoskape. Die gemiddelde liggaamsmassa van geïnfesteerde Dorperskape het toegeneem oor' n 16 week periode met 4.56 kg (15.11 %) vergeleke met die 5.88 kg (18.28%) vir die ongeïnfesteerde kontrole Dorperskape. Vergelykende studies tussen Merino- en Dorperskape ten opsigte van die tempo van skaapbrandsiek letselontwikkeling, het aangetoon dat daar merkbare verskille in die : populasie toename van P. ovis is. Gedurende, Foundation for Research Development, University of the Free State, Bayer Animal Health Division, Fort Dodge (Pty) Ltd, Hoechst Roussel Vet (Pty) Ltd