and life cycle—Viruses
Most viruses attacking cucurbits have a wide host range, which includes carrot, lettuce, tomato, beans,
peppers, and several weed species. Transmission to cucurbits from other host plants requires contact with
plant sap. The most common means of spread is through feeding by insects that have fed on the sap of infected
plants. Usually only one or a few species of insects transmit a specific virus. Many species of aphids
transmit potyviruses and cucumber mosaic virus. Cucumber aphidborne yellows is transmitted by the cotton
aphid and the green peach aphid. The spotted cucumber beetle and other related beetles vector squash mosaic
virus, and the silverleaf whitefly transmits lettuce infectious yellows.