Document Type

Dissertation - Open Access

Award Date

1971

Degree Name

Doctor of Philosophy (PhD)

Department / School

Entomology

First Advisor

Robert W. Kieckhefer

Abstract

Twenty-four coccinellid species, excluding the genus Scymnus, were collected in eastern South Dakota during the 1969-70 growing seasons. Hippodamia convergens Guerin-Meneville, H. tredecimpunctata L., and H. parenthesis (Say), were the most abundant species found in alfalfa and small grains. Reproduction of H. convergens and H. tredecimpunctata occurred in alfalfa, oats, spring and winter wheat, and corn. Field observations indicated that the reproductive cycle required approximately 2½ weeks. The pea aphid, Macrosiphum pisi (Harris), the English grain aphid, M. avenae (Fabricius), and the corn leaf aphid, Rhopalosiphum maidis (Fitch), appeared to be suitable food for these 3 Hippodamia species; the brown ambrosia aphid, M. ambrosiae (Thomas), was toxic to H. tredecimpunctata. Cannibalism and interspecific predation by larvae of H. convergens and H. tredecimpunctata were observed in the field. Hymenopterous parasitism was observed in H. convergens. Adult coccinellids were found to be very flight active. Flights varied in height which was probably related to distance of flight. Habitat destruction (clipping alfalfa) and food requirements were probable cause for much flight activity. Low recapture of marked lady beetles also supported evidence of their highly mobile nature. Of the 3 Hippodamia species, H. convergens was found to be the most variable species in size and elytral maculation but was least variable in the ratio of females to males.

Library of Congress Subject Headings

Ladybugs
Beetles -- South Dakota
Hippodamia

Format

application/pdf

Number of Pages

88

Publisher

South Dakota State University

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