ASSOCIATION BETWEEN RISK OF SEROCONVERSION OF SENTINEL CATTLE TO BLUETONGUE VIRUSES AND CULICOIDES SPECIES (DIPTERA, CERATOPOGONIDAE) IN QUEENSLAND, AUSTRALIA

The association between risk of seroconversion of sentinel cattle to b luetongue viruses and the number of Culicoides brevitarsis Kieffer and C. wadai Kitaoka caught by light traps was investigated using surviva l analysis. Eight sentinel herds that seroconverted to bluetongue viru ses between 1990 and 1994, and for which insect-trapping data were ava ilable, were selected for inclusion in the study. These herds were loc ated at six sites along the eastern coast of Queensland, Australia, fr om approximately latitude 10 degrees South to 25 degrees South. C. bre vitarsis was detected at all locations where sentinel herds were maint ained, whereas C. wadai was detected at only two locations in northern Queensland where four sentinel herds were maintained during the study period. The mean number of C. brevitarsis and C. wadai caught per mon th was 230 and 21, respectively. A significant (P=0.05) positive assoc iation was found between the risk of seroconversion of sentinel cattle to bluetongue viruses and the number of C. wadai caught in the same m onth. (C) 1997 Elsevier Science B.V.