Climate, host and geography shape insect and fungal communities of trees.

Non-native pests, climate change, and their interactions are likely to alter relationships between trees and tree-associated organisms with consequences for forest health. To understand and predict such changes, factors structuring tree-associated communities need to be determined. Here, we analysed the data consisting of records of insects and fungi collected from dormant twigs from 155 tree species at 51 botanical gardens or arboreta in 32 countries. Generalized dissimilarity models revealed similar relative importance of studied climatic, host-related and geographic factors on differences in tree-associated communities. Mean annual temperature, phylogenetic distance between hosts and geographic distance between locations were the major drivers of dissimilarities. The increasing importance of high temperatures on differences in studied communities indicate that climate change could affect tree-associated organisms directly and indirectly through host range shifts. Insect and fungal communities were more similar between closely related vs. distant hosts suggesting that host range shifts may facilitate the emergence of new pests. Moreover, dissimilarities among tree-associated communities increased with geographic distance indicating that human-mediated transport may serve as a pathway of the introductions of new pests. The results of this study highlight the need to limit the establishment of tree pests and increase the resilience of forest ecosystems to changes in climate.

Worldwide diversity of endophytic fungi and insects associated with dormant tree twigs.

International trade in plants and climate change are two of the main factors causing damaging tree pests (i.e. fungi and insects) to spread into new areas. To mitigate these risks, a large-scale assessment of tree-associated fungi and insects is needed. We present records of endophytic fungi and insects in twigs of 17 angiosperm and gymnosperm genera, from 51 locations in 32 countries worldwide. Endophytic fungi were characterized by high-throughput sequencing of 352 samples from 145 tree species in 28 countries. Insects were reared from 227 samples of 109 tree species in 18 countries and sorted into taxonomic orders and feeding guilds. Herbivorous insects were grouped into morphospecies and were identified using molecular and morphological approaches. This dataset reveals the diversity of tree-associated taxa, as it contains 12,721 fungal Amplicon Sequence Variants and 208 herbivorous insect morphospecies, sampled across broad geographic and climatic gradients and for many tree species. This dataset will facilitate applied and fundamental studies on the distribution of fungal endophytes and insects in trees.

Wing morphometrics as a tool for the identification of forensic important Lucilia spp. (Diptera: Calliphoridae).

Blow flies of the genera Lucilia Robineau-Desvoidy (Diptera: Calliphoridae) are considered forensically important species across several regions of the world. Due to the similarity of adults, especially females, the usual methods based on morphology or even molecular techniques can experience some limitations; therefore, alternative or supportive tools are required. Recently, the landmark-based geometric morphometric analysis has been applied to discriminate many insects on genus and species level. Herein, we focus on wing morphometric analysis as a tool in classifying five species of Lucilia; three species from Thailand - L. cuprina (Wiedemann, 1830), L. porphyrina (Walker, 1856) and L. sinensis Aubertin, 1933; and two species from Switzerland - L. caesar (Linnaeus, 1758) and L. illustris (Meigen, 1826). Canonical variate analysis of 233 right wings showed four overlapping clusters of L. cuprina, L. sinensis, L. caesar, and L. illustris with one distinct cluster of L. porphyrina. Eighty-eight to 100 percent of correct classification was achieved, with an UPGMA dendrogram analysis revealing clear-cut branch and sub-branch of five species determined. Results from this study suggested that wing morphometric analysis is a useful tool for the identification of adult Lucilia spp.

Decomposition and insect colonization patterns of pig cadavers lying on forest soil and suspended above ground.

Hanging is one of the most common methods of suicide, and, although it is known that decomposition and patterns of insect fauna colonization of hanging cadavers differ from those of cadavers decomposing on the ground, these differences have only been sparsely studied in Europe so far. We studied the decomposition and insect colonization patterns of ten pig (Sus scrofa domestica) carcasses in a spruce forest near Neuchâtel, Switzerland, over a 32-day period in summer 2013 (July 1st - August 2nd). Five pig carcasses were suspended horizontally in metal cages one meter above the ground and five carcasses were placed directly on the ground. The species occurrence and abundance of Coleoptera and Diptera recovered from passive pitfall traps and collected manually on the carcasses were recorded. Indicator species of decomposition stages and suspended vs. ground cadavers were identified by Indicator Value (IndVal) analysis. The ground carcasses decomposed significantly faster than the suspended carcasses. Coleoptera and Diptera communities differed significantly over time, between treatment, and the treatment effect varied over time. Diptera were evenly distributed among the two treatments. Coleoptera were more abundant and less differentiated on the ground carcasses and represent better indicators of cadavers decomposing on the soil as well as decomposition stages. Our results suggest possible applications such as evaluating if a hanged cadaver has been dropped to the ground, or inversely if a cadaver first lying on the soil has later been hung to fake a suicide. However differences among studies suggest possible effects of meso-climate determined by habitat which should be explored further.

A preliminary study about the spatiotemporal distribution of forensically important blow flies (Diptera: Calliphoridae) in the area of Bern, Switzerland.

To assess the species composition of necrophagous blow flies (Diptera: Calliphoridae) in the area around the federal city of Switzerland, Bern, sampling with baited bottle traps was performed over the course of 34 weeks in 2014. Six locations ranging from urban to forest habitats were sampled weekly or rather biweekly in the winter period. 5580 individuals belonging to 16 species were identified with Lucilia sericata as the most dominant and frequent species, followed by Calliphora vicina. While most individuals were found in the urban habitats, species richness was highest in the forest. Species richness and Chao-Shen entropy estimator peaked in most locations in the summer. In winter only two species were documented (C. vicina, Calliphora vomitoria). The species Lucilia illustris was found to be an indicator species for summer and autumn, while C. vomitoria was found to be an indicator species for the forest location. Entomological cases of the same time period conducted in the Institute of Forensic Medicine Bern were included to compare the species composition. Six blow fly species were found on human bodies which are in line with the monitoring. Of these, L. sericata, C. vicina and Protophormia terraenovae were the most frequent.

Molecular identification and phylogenetic analysis of the forensically important family Piophilidae (Diptera) from different European locations.

Species identification plays an important role in forensic entomology and is mandatory for an accurate calculation of the minimum post-mortem interval. Many important Diptera and Coleoptera taxa of the cadaver community can already be identified by common barcoding approaches, i.e., by sequencing a 658bp region in the mitochondrial cytochrome c oxidase subunit I (coI) gene. Nevertheless, there is still a lack of reference barcodes for species, in particular, that can be found on cadavers at later decomposition stages. Flies of the family Piophilidae illustrate this gap of knowledge perfectly. Due to the fact that a reliable morphological identification key for the immature stages of this flies is still missing and the immature stages of many piophilids cannot be assigned to a certain species, there is need for additional tools to identify forensically relevant taxa. We collected adult piophilid specimens at 10 locations in five European countries: Spain (n=3 locations), Germany (n=3), Portugal (n=2), Poland (n=1) and Switzerland (n=1). Apart from the coI barcoding region, we additionally analyzed a 398bp long region of the nuclear elongation factor 1 alpha (ef1a) and subsequently established the molecular identifier for nine piophilid species. In addition, we present the molecular phylogeny of the examined taxa.