Trapping of larvae of the cattle tick Boophilus microplus by Stylosanthes scabra under grazing conditions

Abstract

Several varieties of the leguminous genus Stylosanthes have the capacity to trap larvae of the tick Boophilus microplus. This capacity was assessed for S. scabra plants collected from grazed fields at two locations, Brian Pastures Research Station and 'The Springs' in central Queensland. Morphological attributes which may affect the capacity of plants to trap tick larvae were recorded. In laboratory tests, plants collected from Brian Pastures trapped 27% of larvae in summer and 12% in winter, whilst plants from 'The Springs' trapped an average of 12%, with no seasonal pattern discernible. The percentage of branches which were sticky was the major determinant of a plant's capacity to trap ticks. Variation in stickiness per se was less important. Frost and burning temporarily reduced tick-trapping capacity, but after four months, burnt plants trapped a higher percentage of larvae than unburnt plants due to the production of sticky regrowth. The implication of the results for the use of S. scabra in tick control programs is discussed.