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

View the project report

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.