Precipitating Antibodies in Cattle Infested by Psoroptes Ovis (Acarina: Psoroptidae)12

Abstract

Precipitating antibodies, as demonstrated by agar-gel diffusion tests, were found in the sera of 23 of 38 Psoroptes ovis-infested cattle when tested against a P. ovis extract and in the sera of 9 of 17 cattle when tested against a P. cuniculi extract. Sera from 5 of 54 P. ovis-uninfested cattle reacted to the P. ovis extract and 3 of 22 reacted to the P. cuniculi extract. Analysis of the P. ovis and the P. cuniculi extracts indicates that they share common antigens. The reaction between the sera of mite-infested cattle and the above antigens is a specific antigenantibody reaction. Extracts of Hypoderma bovis, Otobius megnini, Haematopinus eurysternus, Demodex bovis, cattle tissue, and cattle blood were made and tested with some of the above sera. Only the H. bovis extract gave a specific reaction with the serum of a grub-infested calf. Reactions with the O. megnini and blood extracts were considered nonspecific.