A survey of the ability of tropical legumes in the genus Stylosanthes to trap larvae of the cattle tick, Boophilus microplus (Ixodidae)

Abstract

Stylosanthes viscosa and S. scabra cvv. Fitzroy and Seca have previously been shown to trap host-seeking larvae of the cattle tick Boophilus microplus and could provide a means of controlling cattle ticks in improved pastures. We assessed the ability of 229 accessions from 22 species of the genus Stylosanthes to trap larvae of B. microplus or to prevent them from ascending plant stems. The 3 species that were most effective were S. viscosa, S. scabra and S. guianensis. Only accessions which produced sticky secretions were able to trap tick larvae, but the extent of this ability was related primarily to the density and length of bristles on the stems rather than to the degree of stickiness. The highest percentages of larvae were trapped when stylo stems had short, dense bristles of average stickiness or long sticky bristles of average density. These features were also most effective at preventing larvae from ascending stems. A high density of fine, non-glandular hairs, in conjunction with average stickiness, also prevented larvae from ascending stems.