New Horizons in Insect Science Towards Sustainable Pest Management

159

Vectors of Plant Viruses of Crop

Plants in Southeast Asia

N. Nagaraju, A. S. Padmaja, G. Basana Gowda and

R. N. Pushpa

A. K. Chakravarthy (ed.), New Horizons in Insect Science: Towards Sustainable Pest Management,
DOI 10.1007/978-81-322-2089-3_16, © Springer India 2015

N. Nagaraju () · A. S. Padmaja · G. Basana Gowda ·
R. N. Pushpa
University of Agricultural Sciences GKVK, 560 065
Bangalore, Karnataka, India
e-mail: [email protected]

Abstract

Plant viruses are transmitted by aphids, whiteflies, leafhoppers, plant hop-

pers, thrips, mites, fungi, and nematodes mainly from one host plant to

another. These have been classified as non-persistent, semi-persistent, and

persistent, depending on the length of the period the vector that can har-

bour infectious particles, which can range from minutes to hours (non-

persistent) to days (semipersistent) and to lifetime and even inheritance

by the insect progeny (persistent). Aphids are the vectors for the nonper-

sistent viruses. Some aphids, leaf hoppers, thrips, and whiteflies are the

vectors for different viruses that fit in the persistent category.

Keywords

Insects· Plant viruses · Vectors · Virus–vector relationship

can also transmit these pathogens (Table 1 ). In-

sect and other noninsects transmit 76 % of all the

diseases. However, hemipteran insects transmit a

majority of the vectored viruses (55 %).

Watson and Roberts ( 1939 ) coined the terms

non-persistent and persistent viruses, as a first

attempt to categorize and understand plant virus

vector transmission relationships. The nonpersis-

tent viruses had very short retention times (> 12 h)

in vectors in contrast to persistent viruses where

retention time was 12 h to indefinite. Nonper-

sistent viruses were efficiently transmitted after

relatively brief (< 5 min) acquisition access pe-

riod (AAP) and inoculation access period (IAP),

while persistent viruses required longer AAP and

IAP, and optimum transmission efficiencies were

associated with feeding (Table 2 ). Some of the

Introduction

Many plant viruses cannot spread to other plants
without the help of seeds, tubers, pollen, and
other propagating materials. However, impor-
tantly other major external factor that spread
viruses is a vector. Vectors feed on the infected
plant, become contaminated or infested with the
virus, then move to healthy plants and infect
them by feeding. Arthropods (insects and mites)
are the most common plant virus vectors, though
nematodes and primitive soil microorganisms