G A Tice

Publications of G A Tice

• Ixodid ticks on cattle belonging to small-scale farmers at 4 communal grazing areas in South Africa.

  Authors: N R Bryson, G A Tice, I G Horak, C G Stewart, B J A du Plessis

  Journal of the South African Veterinary Association. 10/2002; 73(3):98-103.

  Ixodid ticks were collected during the period September 1991 to August 1993 from cattle belonging to small-scale farmers utilising 4 communal grazing areas. Three of these were in North West ProvinceIxodid ticks were collected during the period September 1991 to August 1993 from cattle belonging to small-scale farmers utilising 4 communal grazing areas. Three of these were in North West Province and 1 in Mpumalanga province, South Africa. Ten tick species were collected in North West Province and 7 in Mpumalanga. The adults of Amblyomma hebraeum, Rhipicephalus appendiculatus and Rhipicephalus evertsi evertsi were most numerous in North West Province, while in Mpumalanga Boophilus decoloratus comprised more than 75% of the total population. Amblyomma hebraeum was present on all grazing areas, and heavy infestations of adults occurred during the period October to May on 1 of these. Few B. decoloratus were collected in North West Province, chiefly because the sampling method was inadequate, and most of these were present during early summer (October to December) and late summer and autumn (March to May). The initially low population of B. decoloratus in Mpumalanga increased substantially towards the conclusion of the survey, probably because of the cessation of dipping. Boophilus microplus was present in small numbers on 2 grazing areas in the North West Province. Adult Hyalomma marginatum rufipes reached peak numbers from December to February and Hyalomma truncatum from February to April in the North West Province. Only H. marginatum rufipes was collected in Mpumalanga. Rhipicephalus appendiculatus was present on all the grazing areas, with most adults present from December to April. Most adult Rhipicephalus evertsi evertsi were collected from September to April and Rhipicephalus simus was present during the period October-April.

• Ixodid ticks on indigenous goats owned by small-scale farmers in four communal grazing areas in South Africa.

  Authors: N R Bryson, G A Tice, I G Horak, C G Stewart, B J A du Plessis

  Journal of the South African Veterinary Association. 04/2002; 73(1):26-30.

  Indigenous goats belonging to small-scale farmers in 4 communal grazing areas in South Africa were sampled for ixodid ticks during the period September 1991 to May 1993. Three of these areas were inIndigenous goats belonging to small-scale farmers in 4 communal grazing areas in South Africa were sampled for ixodid ticks during the period September 1991 to May 1993. Three of these areas were in the North West Province (Rietgat, Madinyane and Bethany), and one in Mpumalanga Province (Geluk). No tick control was practised unless requested by the owners. Seven ixodid tick species, of which the majority were immature ticks, were collected from the goats in North West Province. Amblyomma hebraeum was the most numerous of these, followed by Rhipicephalus evertsi evertsi and Rhipicephalus appendiculatus. Substantially more ticks were collected from goats at Rietgat than at the Madinyane and Bethany grazing areas. Five tick species were collected at Geluk and R. evertsi evertsi comprised more than 95 % of the total population. At Rietgat and Geluk A. hebraeum nymphs were present on goats throughout the year, while most R appendiculatus nymphs were collected during September and October 1991 and most adults during January and February 1992. At both Rietgat and Geluk most immature R. evertsi evertsi were collected from spring to late summer, while adults were present throughout the year.

• The absence of clinical disease in cattle in communal grazing areas where farmers are changing from an intensive dipping programme to one of endemic stability to tick-borne diseases.

  Authors: G A Tice, N R Bryson, C G Stewart, B Du Plessis, D T De Wall

  The Onderstepoort journal of veterinary research. 10/1998; 65(3):169-75.

  A two-year field study was conducted in four communal grazing areas in South Africa. Sera were collected from young cattle (6-18 months old) in these areas during the winters of 1991 to 1993. TheA two-year field study was conducted in four communal grazing areas in South Africa. Sera were collected from young cattle (6-18 months old) in these areas during the winters of 1991 to 1993. The sera were tested for antibodies to Babesia bovis, Babesia bigemina, Anaplasma marginale and Cowdria ruminantium. In two of the four areas, treatment with acaricide was erratic and dependent on the discretion of individual owners. In these areas the drought of 1992 had a major impact on tick burdens and there were changes in the seroprevalence to tick-borne diseases. In the other two areas there was a reduction in the intensity of acaricide application and this was associated with an increase in seropositivity to the tick-borne diseases. Increases in the prevalence of seropositivity and the presence of endemic instability, as calculated from inoculation rates, were not accompanied by outbreaks of clinical disease. Possible reasons for this are discussed.