The extraordinary diversity and success of insects is mainly based on two large radiations in Holometabola and Acercaria. The latter lineage includes the Hemiptera (true bugs, cicadas, plant lice, whiteflies, and scale insects) and the Thripida (thrips), as well as the Psocodea (barklice and true lice). Acercarians play a major role in most terrestrial ecosystems and include numerous important pest species because of plant-feeding adaptations and/or their frequent function as vectors of animal and plant pathogens. Increasing species diversity within these orders corresponds to the evolutionary transition from chewing mouthparts to stylet-like sucking-piercing mouthparts and this major transformation represented one of the last remaining enigmas in the evolutionary history of insects.

Using innovative preparation and analysis methods an international group of scientists has identified new aspects of the morphology of preserved fossil insect specimens which originate from a mid-Cretaceous amber specimen, part of the collection of the Stuttgart State Museum of Natural History.

Investigation of the internal morphological characteristics of these preserved insects was made by 3D X-ray micro-computed tomography at the TOPO-TOMO beamline at ANKA. The results of the research provide evidence crucial to the reconstruction of the phylogenetic relationships in these “missing link" fossils, and the observations lead to the definition of a new insect order, the Permopsocida.

 

An insect specimen (Psocorrhyncha burmitica gen. et sp. nov. (Archipsyllidae), general habitus) within a mid-Cretaceous Burmese amber	Volume-rendered micro-CT of a specimen: the orange area represents the gut which interestingly contains preserved pollen spores (the inset shows an SEM-micrograph of such a spore, isolated by microscopic dissection

Huang D, Bechly YG, Nel P, Engel MS, Prokop J, Azar D, Cai CY, van de Kamp T9, Staniczek AH, Garrouste R, Krogmann L, Dos Santos Rolo T, Baumbach T, Ohlhoff R, Shmakov A, Bourgoin T, Nel A. (2016): New fossil insect order Permopsocida elucidates major radiation and evolution of suction feeding in hemimetabolous insects (Hexapoda: Acercaria). Scientific Reports, 6: 23004.