Research Methods in Life Sciences Commons^™

Nest Location And Nest Recognition In Two Solitary Bee Species Osmia Lignaria Say And Megachile Rotundata (F.) (Hymenoptera: Megachilidae), Christelle Guédot

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The visual and olfactory cues used in short-range orientation, specifically nest location and nest recognition, were studied in two solitary bee species Osmia lignaria Say and Megachile rotundata (F.) Osmia lignaria, the blue orchard bee, is an important pollinator of orchard crops, such as apples, cherries, and almonds; and M. rotundata, the alfalfa leafcutting bee, is used in commercial pollination of alfalfa. The general objective was to better understand how these two species locate their nests and how improving nest location could benefit crop pollination.

The use of proximal visual landmarks at the nesting site was investigated with …

Factors Relating To Diapause In The Alfalfa Weevil Parasite Bathyplectes Curculionis (Thomson), David S. Parrish

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Biological and ecological factors regulating diapause in the ichneumonid parasite of the alfalfa weevil, Bathyplectes curculionis (Thomson), were studied. In most experiments, both parasites and weevil larvae were maintained in the environmental conditions under study from the emergence of the adult parasite until the evaluation of results.

The factors either preventing or inducing diapause in B. curculionis were found to be an interaction of environmental factors. A long scotophase with cool temperatures prevented diapause. The percentage of nondiapausing parasites increased as the scotophase was increased to 15 hours. Over 15 hours of scotophase, fewer nondiapausing parasites were produced. The optimum …

The "Starvation Effect" And Tryptophan Pyrrolase Activity In The Vermilion Mutant Of Drosophila, Ernest E. Shelton Jr.

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The enzyme tryptophan pyrrolase is controlled by the vermilion locus in Drosophila melanogaster and is normally lacking in the vermilion mutants. During this investigation it has been demonstrated that v¹;bw flies have tryptophan pyrrolase activity when grown under near starvation conditions.

During development of the fly there is a peak of enzyme activity in the early third instar soon after the transfer to starvation medium. A second peak of enzyme activity occurs during the pupal stage. The activity in v¹;bw pupae is about 15% of the activity found in cn bw adults.

In v …