Date of Graduation
Master of Science in Agriculture
College of Agriculture
Galleria mellonella, hemolymph, Nomarski’s differential interference contrast, spherulocytes, sumi ink, oblique illumination filter
Differentiation of insect hemocytes requires microscopes equipped with differential interference contrast (DIC), s.c. Nomarski’s contrast. However, the high price of DIC limits speed and efficacy of hemocyte studies. For my thesis, I developed two low cost microscope sets equipped with custom oblique illumination filters. The oblique illumination filters, that I produced, provided high quality images comparable with those produced by DIC, for a fraction of the cost and allowed me to train laboratory personnel quickly. Microscopes with these oblique illumination filters were used in studies of spherulocytes and for rapid screening of plant essential oils to impair insect immune system. Nine plant essential oils were screened for effects on hemocytes in circulation of Sumi ink-challenged larvae. Galleria mellonella larvae injected with artificial pathogen, Sumi ink, responded by increasing numbers of circulating spherulocytes in a dose-dependent manner. In addition, phagocytosis of Sumi ink particles by spherulocytes was observed. Two oils (bergamot and frankincense) markedly lowered numbers of plasmatocytes and granulocytes in circulation of Galleria mellonella larvae. One (lavender) lowered numbers of oenocytoids.
© Westley David Peterson
Peterson, Westley David, "Using Pseudo Nomarski Contrast to Study Hemocytes of Galleria Mellonella" (2019). MSU Graduate Theses. 3391.