Degree Type

Dissertation

Date of Award

1990

Degree Name

Doctor of Philosophy

Department

Entomology

First Advisor

W. B. Showers

Abstract

The black cutworm, Agrotis ipsilon (Hufnagel), and armyworm, Pseudaletia unipuncta (Haworth), are important pests of corn in the Midwest. Scientific research on these pests has often centered on the damaging larval stages. However, earlier studies indicated that the adults of these species migrate into Iowa cornfields. Therefore, research focusing on the adult stages is needed. Specifically, the daily timing of adult eclosion, nocturnal feeding behavior (both laboratory and field) and migration tracking by pollen analysis are addressed;The time of adult eclosion for black cutworm and armyworm was examined. Peak eclosion of both species occurred during 2200 hr. No differences between sexes were observed. Eclosion times of laboratory colonies that were 18 generations removed from the wild were significantly different from eclosion time of colonies 6 generations removed from the wild. Cold storage of 1 week weakened the hourly emergence peaks in both colonies;Posteclosion feeding of laboratory-reared black cutworm and armyworm was also investigated. More than 70% of each species fed in the laboratory within 1 hour after eclosion. Nearly 87% fed within 6 hours;Feral nocturnal feeding of 36 species of moths upon common Iowa plants was also observed. Lepidoptera in the families Noctuidae, Pyralidae, Arctiidae and Geometridae were collected. The first observations of European corn borer, Ostrinia nubilalis, feeding on nectar were made;Black cutworm and armyworm males, collected from pheromone traps in Iowa and Missouri, as well as male and female black cutworms from blacklight traps in Iowa were examined for pollen. Pollen was found primarily on the proboscis and in decreasing frequency on the eyes, legs and antennae. Fourteen moths collected in Iowa and Missouri were marked with the exotic pollens of Pithecellobium spp. and Calliandra spp. Pithecellobium was found on a single male armyworm. The closest location of these plants is Texas and northern Mexico. Moths marked with exotic pollen were collected during May in Iowa, and April in Missouri. These results provide empirical evidence for immigration into Missouri and Iowa from a more southern location.

DOI

https://doi.org/10.31274/rtd-180813-9136

Publisher

Digital Repository @ Iowa State University, http://lib.dr.iastate.edu/

Copyright Owner

William Hurston Hendrix, III

Language

en

Proquest ID

AAI9100440

File Format

application/pdf

File Size

280 pages

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