Components of seasonal soybean infestation by Heliothis zea in eastern Virginia, with emphasis on multivariate analysis of field susceptibility

Heliothis zea (Boddie) (Lepidoptera: Noctuidae) density, development, and relationships with host crops were studied in eastern Virginia. Six instars occur. The larval population in corn is the reservoir for the generation in soybeans. An estimator, based on the reservoir population, permitted calculation of the larval density in soybeans. An index, based on blacklight trap and emergence data, permitted precise timing ot peak moth flight to soybeans. Regression analyses of biotic and abiotic factors revealed that soybean plant morphometrics best explained corn earworm densities. Discriminant analyses on empiricala priori soybean field susceptibility categories (described by plant morphometrics) classified five levels of anticipated maximum larval densities 80 - 98 percent correctly. Development of highest larval densities was synchronized with overall plant growth and specific pod development: third and fourth instars were present during rapid pod elongation, while fifth and sixth were present during rapid pod volume increase.

Name thesis:degree_name

Master of Science

Level thesis:degree_level

masters

Discipline thesis:degree_discipline

Entomology

Department dc:contributor.department

Entomology

Grantor dc:publisher

Virginia Tech

Year dc:date.issued

1978

Author dc:creator

• Knausenberger, Janice G. Burt

Chair dc:contributor.committeechair

• Allen, William A.

Committee members dc:contributor.committeemember

• Smith, John C.
• Giles, Robert H. Jr.
• Grayson, James McD.

• insect density

Statement dc:rights

• In Copyright

Licence dc:rights.uri

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

Dc Identifier Other

etd-07162009-040215

OAI identifier oai:identifier

oai:vtechworks.lib.vt.edu:10919/34031