Developing an integrated management program for cucurbit yellow vine disease, an emerging threat to the Northeast

Commodities

• Vegetables: cucurbits

Practices

• Pest Management: cultural control, disease vectors, integrated pest management, prevention

Cucurbit yellow vine disease (CYVD) affects most commercially
available cucurbits. Disease symptoms include yellowing, leaf
scorching, and stem discoloration. CYVD is caused by the
bacterium Serratia marcescens and is vectored by the
squash bug (Anasa tristis), a common pest of cucurbits.
Squash bugs acquire S. marcescens by feeding on the
vascular tissue of infected plants, and the bacterium can persist
in the insect's hemocoel through molting and overwintering
events. Our project aims to determine the distribution,
overwintering, and recent CYVD entry through genetic diversity
studies of S. marcescens isolates collected in New York
and across the Northeast. Furthermore, we seek to investigate the
percentage of squash bugs that carry S. marcescens in a
field at different time points, starting with the overwintering
adults; we will collect squash bugs from different farms and test
them for the presence of S. marcescens using molecular
techniques. Lastly, we seek to determine identify the host range
of S. marcescens isolates collected from cucurbits to
determine the risk of infection with the presence of these
strains in the state. Overall, this research will provide
information needed to develop an integrated pest management
program for this emergent disease.

1. Collect Serratia marcescens isolates from
   NY and the different Northeastern states for whole genome
   sequencing to understand pathogen overwintering and geographic
   distribution

Hypothesis

There will be low genetic diversity between S.
marcescens isolates collected from different states in the
Northeast due to pathogen overwintering and not introduction of
new isolates.

2. Collection of squash bugs at different time points during the
   season to determine the percentage of squash bugs carrying S
   marcescens and how it changes over time 

Hypothesis:

There will be a percentage of squash bugs that carry S.
marcescens overwinter and this percentage will increase over
the growing season as newly hatched nymphs feed on infected
plants.

3. Host range study of  S. marcescens isolates
   into other crops of economic importance to understand the risk of
   disease spread into other specialty crops in the Northeast

Hypothesis:

Isolates of S. marcescens coming from cucurbit can
infect other crops of economic importance in New York.