Infection of Manduca sexta with both host-specific and non-host specific pathogens

The host ranges of the microsporia: Vairimorpha disparis and Endoreticulatus schubergi, and the viruses LdCPV and LdMNPV were characterized. All four pathogens are considered host specific to Lymantria dispar, the gypsy moth, and its close relatives. I used these pathogens to try and infect a non-target host, Manduca sexta. I predicted that E. schubergi and LdCPV would have a high infection rate as opposed to V. disparis and LdMNPV because E. schubergi and LdCPV have relatively broad host ranges. The M. sexta larvae were infected on the first day of the third instar and after 24-hours, five of the fifteen larvae in each treatment were dissected and had their midgut frozen to later test for any immune response. All of the other larvae were observed until they reached the fifth instar, then they were dissected to determine occurrence of infection. Finally, a BradFord Assay and a 2-D gel analysis were performed to quantify, and to further identify midgut proteins from M. sexta for each treatment, 24-hours after infection. My results showed that M. sexta was not susceptible to any of the pathogens nor did the pathogens effect the host’s development. I propose to repeat the study to determine if earlier instars of M. sexta are susceptible to this set of pathogens. The 2D-gels revealed that third instar M. sexta showed a physiological response within 24 hours of infection. The identity of the proteins that were up or down regulated will be determined in a future project.