Virus-vector

Question 1

Relation between plants and viruses.

Answer 1

Viruses that are introduced into plants by insects not only cause damage to the plant but also change the way in which subsequent vectors interact with the plant as well – visual cues (discoloration in plant tissue)

Question 2

Mechanical transmission via blocked proventriculus of beetles.

Answer 2

Causes them to regurgitate while feeding because plant tissue is difficult to digest is also an important method of virus transmission from insect to plant.

Question 3

Barrier crops for hemipterans.

Answer 3

Most Hemipterans are attracted to brown/yellow crops (indicative of virus) – this can be used as a strategy of IPM by planting barrier crops.

Question 4

Components of Virus Epidemiology a “Disease Tetrahedron”.

Answer 4

In virus epidemiology, the virus pathosystem can be described as “Disease Tetrahedron,” which means the environment, virus, susceptible hosts and vectors can affect each other.

First, virus can affect plants (host), the infestation of virus can stimulate the constitutive defense of plant, releasing chemical compounds.

Second, the vectors will be influenced during virus transmission on behavior and life history levels.

Question 5

Why is it important to prevent virus transmission?

Answer 5

First, the vegetative virus can cause yield loss. Virus can significantly increase the yield reduction in sweet potatoes.
Second, the vegetative virus might have a negative effect on the quality of cultivars. For example, certain strains of virus PVY (NTN, N:O), which cause tuber necrosis, can lead to the low quality of potatoes.
Third, virus can reduce seed viability.

Question 6

What are the 4 modes of virus transmission?

Answer 6

1. Non-persistent, non-circulative Stylet-Borne Transmission
2. Semi-persistent Foregut-Borne Transmission
3. Persistent-Circulative Transmission
4. Persistent-Propagative Transmission

Question 7

Main vectors of virus transmission.

Answer 7

55% of vectors belong to Hemiptera (28% of them are aphids)
7% are Coleopterans
2% are Thysanopterans.

Question 8

How do Hemipteran, Thysanopteran, and Coleoptera transmit virus?

Answer 8

For Hemipteran and Thysanopteran pests, virus will be transferred while they use haustellate mouthparts to suck the sap of plants. For Coleopterans, the virus will infect through wounds created by beetles’ chewing mouthparts.