Terrestrial arthropods group

Arthropods comprise more than 80 percent of all described living animal species. This megadiversity provides ample opportunities to study evolution and morphology as well as biodiversity decline in non-model organisms. The evolution of novel and adapted structures is a central theme in evolutionary morphology, and represents fascinating examples of processes that generate diversity of forms, functions and also species. By an integrative organismic approach, we study the morphological disparity of arthropod organs/body plans and their evolutionary transformations in context with ecological traits.

Research topics

• Insect functional and evolutionary morphology

Harald Krenn

Insect mouthparts represent modified arthropod appendages. This diversity of feeding devices provides numerous examples for the investigation of constraints and options in organ evolution. Our integrative approaches search for explanations of form-function relationships in the evolution of insect mouthparts in context with feeding techniques of flower-visiting insects.

• Arthropods in their environments
  

Barbara-Amina Gereben-Krenn, Harald Krenn, Martin Hepner

Biodiversity of arthropods is still insufficiently studied even in Europa and basal data are missing. Our research aims to investigate distribution, abundance and biology on focal groups. The approach uses various field work methods and DNA barcoding to contribute for natural conservation of arthropods. We include biological education and citizen scientists approaches to take responsibility for biological conservation problems.

• Circulatory organs

Harald Krenn, Günther Pass, Barbara-Amina Gereben-Krenn

Insects possess auxiliary pumps for hemolymph supply of body appendages in addition to the dorsal vessel. The accessory pulsatile organs for the hemolymph supply in the wings are located beneath the tergite of each winged segment. They suck hemolymph from the posterior wing veins through cuticular tubes projecting along the tergites. All wing circulatory organs consist of a pump casing, formed by the scutellum, and an associated myofibrilar pulsatile component. They can be formed either by modifications of the dorsal vessel or by muscular diaphragms, which are attached to, or separate from, the dorsal vessel. In Holometabola, convergent evolutionary trends can be reconstructed leading from dorsal vessel modifications to separate unpaired or paired pulsatile diaphragms ("wing-hearts"). Spatial constraints resulting from modifications of the flight apparatus are discussed as possible causes for the multiple parallel evolution of wing-hearts.