ABSENCE OF TRANSOVARIAL TRANSMISSION OF BLUETONGUE VIRUS IN CULICOIDES-VARIIPENNIS - IMMUNOGOLD LABELING OF BLUETONGUE VIRUS-ANTIGEN IN DEVELOPING OOCYTES FROM CULICOIDES-VARIIPENNIS (COQUILLETT)

1. 1. Culicoides variipennis midges were fed on a blood meal containing bluetongue virus (BTV) serotype 11 (BTV-11) and on four subsequent non-infective blood meals at 4-day intervals. 2. 2. Eggs were collected before each blood-feeding and reared to adults. 3. Progeny from each egg batch were incubated for 14 days (20°C, 40-60% RH) before plaque assay. 3. 4. Oocytes from several parent flies were sectioned for immunoelectron microscopy. 4. 5. Thirty-two percent of the parent females tested by plaque assay were positive for BTV. 5. 6. All 993 progeny flies were negative for BTV. 6. 7. BTV antigen was dense in proteid yolk bodies and in the vitelline membrane of the developing oocytes. © 1990.