By Ismael Escobar and Dr. Rebecca Creamer
ASSURED Program 2007
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A problem in the USA since 1899
Infects crops and weeds
The crops are peppers, tomatoes,
sugarbeets, spinach, melons and beans
Youngest plants most susceptible to infection
Transmitted by the leafhopper
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Disease reported in peppers
in NM in 1927
Severely stunted plants
Some plants have chlorotic
rolled leaves
Small rounded fruit
Stiff plants with brittle leaves
Symptoms appear 1-2 weeks
after infection
Plants infected when young
may die
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Feeds on a wide host range of plants
Prefers semi-arid and arid areas
Can transmit viruses to plants on which it
can’t complete its life cycle
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3-3.5 mm length
Robust with lots of spines
Light tan to yellowish to gray
Color and size vary slightly
with season
Found throughout western USA
3 morphs - summer, winter,
and migratory
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Transmits virus in a circulative manner
Can acquire virus after feeding for 15 min, but with longer
feeding (48 hr) acquires more virus
Can transfer virus to healthy plant with few minutes of
feeding, but transmit better if longer
Can continue to transmit the virus for days
Requires 4 hr latent period in insect before transmitting
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Heavy seeding
Weed removal
Plant resistance in bean, sugarbeet, tomatoes, none in chile
Kaolin sprays
Insecticides - to decrease leafhopper numbers
Predictive model
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To determine the preference of the Beet
leafhopper between Tabasco and NM64.
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The NM64 is going to be the more
susceptible to be affected by the virus.
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Commercial varieties susceptible to, other
Capsicum species appear to have some level
of resistance.
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Tabasco vs. NM64
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Plants were grown in greenhouse
Cotyledons were caged in sets of 4 with 5
leafhoppers for 19 hours.
After 2 weeks plants were set for staining,
DNA extraction and PCR.
Leaf Staining (Acid Fuschin)
 Confirmation by microscope by
staining stylet tracks and punctures
 Examined 1 leave/plant
 Extraction/PCR
 PCR using CP4r & CP6f
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Tabasco plants with leafhoppers had an average of 6.3
punctures per leaf and the range was from 0 to 28. Stylet
tracks had an average of .14
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NM64 with leafhoppers had an average of 15.6 punctures per
leaf and the range was from 6 to 33. Stylet tracks had an
average of .2
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None of the plants with leafhoppers tested positive to Curly
Top Virus.
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Tabasco plants without leafhoppers had an
average of 0.4 punctures per leaf and no
stylet tracks.
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NM64 plants without leafhoppers had an
average of 2.8 punctures per leaf and no
stylet tracks.
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None of the plants without leafhoppers
tested positive to Curly Top Virus.
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NM64 had a higher number of punctures than
Tabasco due to preference of the leafhopper.
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Plants without leafhoppers had punctures
due to white flies in the greenhouse.