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Ecology Of Aroga Websteri Clarke In Curlew Valley, Utah-Idaho, Reed L. Kirkland

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The ecology, life history, and population dynamics of the sagebrush defoliator, Aroga websteri Clarke, were studied in the field and laboratory. The defoliator has one generation a year at the Curlew Valley site. It overwintered in the egg stage and passed through five larval instars. Ten parasite species attacked the defoliator at the study site. Four species, Orgilus ferus, Phaeogenes sp., Spilochalcis leptis, and Apanteles cacoeciae, contributed over 75 percent of the total incidence of parasitism. Parasitism ranged from 20 to 76 percent in 1971, but only ranged from 6 to 29 percent in 1972. This decrease …

A Study Of A Heron Nesting Colony, Linden J. Leatham

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Herons are well known because of their gregarious nesting habits. Like many others of the lower orders of birds they nest together in pure or mixed colonies of many different combinations and under diverse living conditions. The population of different colonies may vary from a few pairs to many thousands of pairs depending upon the nature and extent of the breeding area, the food supply available and the protection afforded either by natural or artificial means.

In Utah and adjacent areas of bordering states, many types of heron associations have been studied and reported by ornithological workers. Breeding colonies of …