A Refresher on Common Floriculture Viruses and How They Spread
April 3, 2026 Once a plant with a virus has been found in the greenhouse, it is important to understand the types of viruses and their transmission. Common viruses that affect floriculture crops include:
- Tomato spotted wilt virus
- Impatiens necrotic spot virus
- Tobacco mosaic virus
The host range and method of transmission of these viruses vary; this impacts the management strategy that should be implemented. For more on how to manage these viruses, see “How to manage plant viruses in the greenhouse.”
Tomato spotted wilt virus and impatiens necrotic spot virus are Tospoviruses, which are vectored by insects and seed. Tobacco mosaic virus is a Tobamovirus, which is vectored mechanically. For more information on the biology of viruses, check out the book “Plant Virus and Viroid Diseases in the Tropics” by K. Subramanya Sastry.
Virus Transmission
Viruses can be spread in different ways. Some of the ways are:
- From a parent plant to the next generation of plants via seeds or propagated cuttings.
- By an insect vector, such as the tomato spotted wilt virus and impatiens necrotic spot virus.
- By a mechanical vector, such as the tobacco mosaic virus.
Insect Vectors
The majority of the known plant viruses are transmitted by insect species in the order Hemiptera, according to the International Committee on Taxonomy of Viruses. Insects in this group include aphids and whiteflies, which are common greenhouse pests. These insects, with thin, needle-like mouthparts called stylets, are common vectors of insect-transmitted viruses.
Insects can transmit viruses in two main ways:
- Non-persistently
- Persistently
Non-persistent viruses can be picked up by the insect quickly and spread by the insect for a relatively short time (minutes or hours) after feeding on or probing an infected plant. These are viruses that can spread quickly as the insects move around in the crop.
Persistent viruses take longer (days) for the insect to pick up and are carried within an insect for a long period of time, in many cases for the entire lifetime of the insect. In general, these viruses take longer to spread around in the crop.
For additional information on common floriculture viruses, including manual/mechanical modes of transmission through workers and plant tissue, please read the original article written by Heidi Lindberg.
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