Bean Leaf Beetle: Impact of Leaf Feeding Injury on Snap Beans, Host Plant Choice and Role as a Vector of Bean Pod Mottle Virus in Virginia

The bean leaf beetle (BLB), Cerotoma trifurcata (Forster) (Coleoptera: Chrysomelidae), is a pest of commercially produced legumes in eastern Virginia. Field cage and manual-defoliation studies were conducted in Virginia to determine an economic impact of BLB. In the manual-defoliation study, snap bean plants had significant yield loss when > 25% of leaf area was removed. In the field cage experiments, I was unable to establish beetle densities per plant to impact yield. Host plant selection by BLB was done in laboratory and field studies with snap bean, lima bean, and soybeans. Laboratory studies showed that BLB preferred snap bean and lima bean over soybean. Field studies did not showed no preference. A survey was conducted on the Eastern Shore of Virginia determine the epicenter of BPMV. Soybean leaves and beetles were collected and assessed for BPMV by ELISA or TBIA. Beetles at the ESAREC were BPMV-positive upon emergence from overwintering sites, but the virus load was low when tested by ELISA. This suggests acquisition of virus from a source other than infected cultivated legumes. To find the potential inoculum sources of BPMV in eastern Virginia, leguminous weeds and perennial weeds were tested for BPMV. Four weed species gave BPMV-positive tissue blots including: Oxalis stricta, Rumex acetosella, Trifolium pretense, and Trifolium repens. Insecticidal seed treatment of thiamethoxam on soybean seeds was evaluated to test the efficacy. Leaf area eaten and beetle mortality was measured. The thiamethoxam seed treatment protected soybean seedlings from beetle feeding through the V2 stage of growth.

Name thesis:degree_name

Master of Science in Life Sciences

Level thesis:degree_level

masters

Discipline thesis:degree_discipline

Entomology

Department dc:contributor.department

Entomology

Grantor dc:publisher

Virginia Tech

Year dc:date.issued

2011

Author dc:creator

• Cassell, Meredith Edana

Chairs dc:contributor.committeechair

• Schultz, Peter B.
• Kuhar, Thomas P.

Committee members dc:contributor.committeemember

• Salom, Scott M.
• Tolin, Sue A.
• Pfeiffer, Douglas G.

• Cerotoma trifurcata
• Snap Bean
• Bean Pod Mottle Virus
• Mechanical Defoliation
• Exclusion Cage
• Feeding Preference

Statement dc:rights

• In Copyright

Licence dc:rights.uri

• http://rightsstatements.org/vocab/InC/1.0/

Language dc:language.iso

en_US

Dc Identifier Other

etd-05162011-233118

OAI identifier oai:identifier

oai:vtechworks.lib.vt.edu:10919/76768