| bluetongue epidemiology in the caribbean region: serological and entomological findings from a pilot sentinel system in trinidad and tobago. | when monitored by the agar gel immunodiffusion test for antibody to bluetongue viruses, a sentinel flock of twenty-five lambs remained seropositive through the year, whereas in a sentinel herd of twenty calves only two individuals seroconverted and these became negative again within 2 months. a light trap operated with the calf herd yielded high numbers of culicoides insignis lutz (over 18,000 per trap night) along with c. filariferus hoffman, c. pusillus lutz, c. leopoldi ortiz, c. foxi ortiz, ... | 1989 | 2562417 |