Description of the larva of Holocentropus insignis Martynov 1924 (Trichoptera: Polycentropodidae) with notes on biology and distribution.

The hitherto undescribed larva of Holocentropus insignis Martynov 1924 was collected in Denmark, the Netherlands, and Finland. Based on larval morphology and DNA association with adults, we were able to distinguish the larva of H. insignis from other Holocentropus species known to occur in Europe and confirm its identification. We provide morphological features to separate H. insignis from the other known species within the genus and give an updated key to all known European larvae of Holocentropus. Extensive notes on the life cycle, biology, and distribution of H. insignis are given.

An updated list of type material of Ephemeroptera Hyatt & Arms, 1890, deposited at the Zoological Museum of Hamburg (ZMH).

The type specimens of Ephemeroptera (Insecta) housed at the Zoological Museum of Hamburg (ZMH) are compiled in this document. The current nomenclature of all species is given. In total, Ephemeroptera type material of ZMH encompasses 161 species. Fifty-one holotypes and five lectotypes are present. Forty-one species are represented by syntypes, 85 by paratypes and five by paralectotypes. Material of two species (Cinygma asiaticum Ulmer, 1924 and Pseudocloeon klapaleki Müller-Liebenau, 1982) is missing. The present catalogue is an updated version of Weidner (1964a).

The larval head anatomy of Rhyacophila (Rhyacophilidae) with discussion on mouthpart homology and the groundplan of Trichoptera.

The external and internal features of the larval head of Rhyacophila fasciata (Trichoptera: Rhyacophilidae) were described in detail. Anatomical examinations were carried out using a multimethod approach including histology, scanning electron microscopy, confocal laser-scanning microscopy, microcomputed tomography, and computer-based three-dimensional reconstructions. Additionally, the information on the larval head of Limnephilus flavicornis (Limnephilidae) and Hydropsyche angustipennis (Hydropsychidae) available in the literature were reinvestigated. These anatomical data were used to address major questions of homology and terminology, that is, the ventral closure of the head capsule, the sclerites, and appendages of labium and maxilla and their muscles. These topics were discussed by summarizing the main hypotheses present in the literature and a critical inclusion of new findings. Consequently, the inner lobe of the maxilla very likely represents the galea. The distal maxillary sclerite (palpifer) is an anatomical composite formation at least including dististipes and lacinia. Based on these homology hypotheses several potential groundplan features of the larval head of Trichoptera were reconstructed. The head of Rhyacophila shows several presumably plesiomorphic features as for instance the prognath orientation of the mouthparts, the well-developed hypocranial bridge, the triangular submentum and eyes composed of seven stemmata. Derived features of Rhyacophila are the reduced antennae, the anterior directing of three stemmata and the shift of the tentorio-stipital muscle to the mentum.

Phylogenomics resolves the timing and pattern of insect evolution.

Insects are the most speciose group of animals, but the phylogenetic relationships of many major lineages remain unresolved. We inferred the phylogeny of insects from 1478 protein-coding genes. Phylogenomic analyses of nucleotide and amino acid sequences, with site-specific nucleotide or domain-specific amino acid substitution models, produced statistically robust and congruent results resolving previously controversial phylogenetic relations hips. We dated the origin of insects to the Early Ordovician [~479 million years ago (Ma)], of insect flight to the Early Devonian (~406 Ma), of major extant lineages to the Mississippian (~345 Ma), and the major diversification of holometabolous insects to the Early Cretaceous. Our phylogenomic study provides a comprehensive reliable scaffold for future comparative analyses of evolutionary innovations among insects.