Low Temperature Tolerance and Immune Function of Horned Passalus Beetle Odontotaenius disjunctus (Illiger)

Author

Wesley Douglas Rhinehart

Date

2025

Document Type

Thesis

Degree Name

Master of Science

Department

Biology

Committee Chair

Leigh Boardman

Committee Member

Duane McKenna

Committee Member

James Adelman

Abstract

Temperature has a strong influence on physiology. Additional environmental stressors may affect how an insect responds to temperature stress. To study interactions between low temperature and immune stress, I used adult horned passalus beetles, Odontotaenius disjunctus, and nematodes, Chondronema passali. I investigated the effects of population, seasonality, and C. passali load on three different measures of O. disjunctus low temperature tolerance (critical thermal minimum, chill coma recovery time, and supercooling point) and did not find any effects. I investigated interactions between low temperatures and immune stress by testing the effect of low temperature exposure on the immune response, which had no impact, and immune challenge on CCRT, which was significantly decreased. I also assessed nematode load in these beetles, but it was not correlated with melanization. My work describes the low temperature tolerance of O. disjunctus and builds a foundation for more complex study in the future.

Comments

Data is provided by the student.

Library Comment

PDF

Notes

Embargoed until 04-17-2027

Recommended Citation

Rhinehart, Wesley Douglas, "Low Temperature Tolerance and Immune Function of Horned Passalus Beetle Odontotaenius disjunctus (Illiger)" (2025). Electronic Theses and Dissertations. 3750.
https://digitalcommons.memphis.edu/etd/3750