Abstract
Experiments on the virus‐vector relationship of the Trinidad cowpea mosaic virus, transmitted by Ceratoma ruficornis, gave the following results: ability to infect decreased with increasing time after ceasing to feed on infected plants, but vectors remained infective for 14 days (much longer than the longevity in vitro of the virus at glasshouse shade temperatures of 23–31°C.); the beetles transmitted more consistently after longer feeding on infected plants, though feeds of under 5 min. made them efficient vectors; the proportion of plants infected increased with the amount of feeding damage on them; fasting the vectors before feeding on infected plants increased voracity but had no effect on their ability to transmit; beetles became infective immediately after feeding on infected plants. Cowpeas were infected by inoculation with macerated infective vectors or with juice regurgitated by vectors. There is no evidence that aphids or other sucking insects can transmit the virus. It seems similar to squash mosaic and turnip yellow mosaic, for vectors of all three viruses probably transmit by regurgitating infective juice during feeding.