Advisor: Harald Krenn

Master's Defensio

Monday, November 11th, 2024, 10:00 am CET
SR 4.1, UBB
Djerassiplatz 1, 1030 Vienna

Abstract

The lepidopteran proboscis is a co-evolutionary success story that began over 100 Million years ago. As an adaption to different food sources, the length of the proboscis shows high levels of variation, whilst general morphology is astonishingly uniform within the Glossata. The muscular structures of the very long proboscis and the stipes pump of Manduca sexta are described in detail using MicroCT and semi-thin sections to create 3D-reconstructions. Basal galeal muscles as well as the intrinsic galeal muscles of five proboscis regions are investigated and compared to existing results of other species. Two sets of oblique intrinsic muscles are present from the proximal to the tip region. The stipes muscles are very large and some have multiple portions and origins, which fits well into the assumption that large galeal lumina generally correlate with large stipes muscle sets. It is remarkable, that in all investigated Lepidoptera, the relative number of individual intrinsic galeal muscles is reported to be higher and their length shorter in species with a proboscis that exceeds their body length. This study is the first to describe in detail the intrinsic galeal muscles of a long-tongued moth.