Document Type

Dissertation - Open Access

Award Date

1973

Degree Name

Doctor of Philosophy (PhD)

Department

Entomology

First Advisor

Benjamin H. Kantack

Abstract

A total of 121 indigenous insect taxa representing 9 orders, 64 families, 103 genera and 118 species was collected from Canada thistle (Compositae: Cirsium arvense (L.) Scop.) in South Dakota during 1970 through 1973. This survey identified the major phytophagous and entomophagous insect fauna associated with this noxious weed. The common phytophagous species observed feeding on thistle were all polyphagous and failed to control Canada thistle below the economic level. Field cage releases of adult Ceutorhynchus litura (F.) weevils were made on a thistle infested pasture site located in east central South Dakota during 1972-1973. Ninety-nine weevils were released in 1972 and approximately 150 in 1973. Initial overwintering success was observed when 2 adults were found in the field cage in April and May 1973. The thistle stand in the field cage declined during the summer due to insect damage caused by large infestations of the aphid, Dactynotus cirsii (L.), the four-lined leaf bug, Poecilocapsus lineatus (F.), and possibly the weevil C. litura. These results indicate that C. litura probably can be colonized in South Dakota. No natural enemies of this insect were found during the study. Attempts to establish a laboratory colony of the tortoise beetle, Cassida rubiginosa Mull., were not successful.

Library of Congress Subject Headings

Canada thistle
Weeds -- Biological control

Format

application/pdf

Publisher

South Dakota State University

Included in

Entomology Commons

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