The localization and structure of a neurohemal H-organ in Acrida bicolor (Thunberg) and Locusta migratoria (Linneaus) (Orthoptera)

Acrida bicolor (Thunberg) and Locusta migratoria (Linneaus) nymphs were taken as objects to investigate the presence of neurohemal H-organ in Orthoptera of which was previously reported in Lepidoptera. A triangle-shaped H-organ was clearly observed in between the suboesophagial and prothoracic ganglions in two species

Data from: Tournament ABC analysis of the western palaearctic population history of an oak gallwasp, Synergus umbraculus

Approximate Bayesian computation (ABC) is a powerful and widely used approach in inference of population history. However, the computational effort required to discriminate among alternative historical scenarios often limits the set that is compared to those considered more likely a priori. While often justifiable, this approach will fail to consider unexpected but well-supported population histories. We used a hierarchical tournament approach, in which subsets of scenarios are compared in a first round of ABC analyses and the winners are compared in a second analysis, to reconstruct the population history of an oak gallwasp, Synergus umbraculus (Hymenoptera, Cynipidae) across the Western Palaearctic. We used 4233 bp of sequence data across 7 loci to explore the relationships between four putative Pleistocene refuge populations in Iberia, Italy, the Balkans, and Western Asia. We compared support for 148 alternative scenarios in eight pools, each pool comprising all possible rearrangements of four populations over a given topology of relationships, with or without founding of one population by admixture and with or without an unsampled ‘ghost’ population. We found very little support for the directional ‘out of the east’ scenario previously inferred for other gallwasp community members. Instead, the best-supported models identified Iberia as the first regional population to diverge from the others in the late Pleistocene, followed by divergence between the Balkans and Western Asia, and founding of the Italian population through late Pleistocene admixture from Iberia and the Balkans. We compare these results with what is known for other members of the oak gall community, and consider the strengths and weaknesses of using a tournament approach to explore phylogeographic model space

DIYABC sequence datafile for Synergus umbraculus

Sequence data for seven loci for Synergus umbraculus populations from four putative refugial populations, in a format allowing analysis in DIYABC v1.0.4.46beta

The ongoing range expansion of the invasive oak lace bug across Europe: current occurrence and potential distribution under climate change

In recent years, the oak lace bug, Corythucha arcuata, has emerged as a significant threat to European oak forests. This species, native to North America, has in the last two decades rapidly extended its range in Europe, raising concerns about its potential impact on the continent's invaluable oak populations. To address this growing concern, we conducted an extensive study to assess the distribution, colonization patterns, and potential ecological niche of the oak lace bug in Europe. We gathered 1792 unique presence coordinates from 21 Eurasian countries, utilizing diverse sources such as research observations, citizen science initiatives, GBIF database, and social media reports. To delineate the realized niche and future distribution, we employed an ensemble species distribution modelling (SDM) framework. Two future greenhouse gas scenarios (RCP 4.5 and RCP 8.5) were considered across three-time intervals (2021–2040, 2061–2080, and 2081–2100) to project and evaluate the species' potential distribution in the future. Our analysis revealed that significant hotspots rich in host species occurrence for this invasive insect remain uninvaded so far, even within its suitable habitat. Furthermore, the native ranges of Turkey oak (Quercus cerris L.) and Hungarian oak (Quercus frainetto L.) species offer entirely suitable environments for the oak lace bug. In contrast, the pedunculate oak and sessile oak distribution ranges currently show only 40 % and 50 % suitability for colonization, respectively. However, our predictive models indicate a significant transformation in the habitat suitability of the oak lace bug, with suitability for these two oak species increasing by up to 90 %. This shift underlines an evolving landscape where the oak lace bug may exploit more of its available habitats than initially expected. It emphasises the pressing need for proactive measures to manage and stop its expanding presence, which may lead to a harmful impact on the oak population across the European landscape. © 2024 The Author

The population genetic structure of Corythucha ciliata (Say) (Hemiptera: Tingidae) provides insights into its distribution and invasiveness

Corythucha ciliata ( Say), an invasive pest originating from North America, causes severe damage on sycamore trees. However, little is known about the population genetics and evolutionary forces underlying the invasiveness of this important pest. In the present study, we use three mitochondrial genes ( COI, ND1 and ND5) and nine microsatellite markers to investigate the population genetics of C. ciliata and retrace its spread through China. The results suggest a low level of genetic diversity in Chinese and European populations of C. ciliata. Our results indicate that populations of C. ciliata have obvious genetic structure, and genetic differentiation is not caused by geographic isolation. In median- joining networks, we observed a higher frequency of shared haplotypes in groups 1 and 3. Based on gene flow and approximate Bayesian computation analyses, we discovered that C. ciliata first invaded the east coast of China and subsequently moved inland. Demographic analysis suggested that populations of C. ciliata in China may have undergone a recent bottleneck effect. Finally, our results suggest that population structure, high gene flow and environmental conditions have favored the broad invasiveness of this important pest