Dagger nematodes of the genus Xiphinema include a remarkable group of invertebrates of the phylum Nematoda comprising ectoparasitic animals of many wild and cultivated plants. Damage is caused by direct feeding on root cells and by vectoring nepoviruses that cause diseases on several crops. Precise identification of Xiphinema species is critical for launching appropriate control measures. We deciphered the cryptic diversity of the Xiphinema hispanum-species complex applying integrative taxonomical approaches that allowed us to verify a paradigmatic example of the morphostatic speciation and the description of a new species, Xiphinema malaka sp. nov. Detailed morphological, morphometrical, multivariate and genetic studies were carried out, and mitochondrial and nuclear haploweb analyses were used for species delimitation of this group. The new species belongs to morphospecies Group 5 from the Xiphinema nonamericanum-group species. D2-D3, ITS1, partial 18S, and partial coxI regions were used for inferring the phylogenetic relationships of X. malaka sp. nov. with other species within the genus Xiphinema. Molecular analyses showed a clear species differentiation not paralleled in morphology and morphometry, reflecting a clear morphostatic speciation. These results support the hypothesis that the biodiversity of dagger nematodes in southern Europe is greater than previously assumed.

Reniform nematodes of the genus Rotylenchulus are semi-endoparasites of numerous herbaceous and woody plant species roots and occur largely in regions with temperate, subtropical, and tropical climates. In this study, we provide new records of the nematode Rotylenchulus macrosoma in eight European countries (Czech Republic, France, Germany, Hungary, Italy, Romania, Serbia, and Portugal), in addition to the six Mediterranean countries (Greece, Israel, Jordan, Spain, Syria, and Turkey) where the nematode was previously reported. Four new host species (corn, pea, wheat, and an almond-peach hybrid rootstock) are added to the recorded host species (bean, chickpea, hazelnut, peanut, soybean, and wild and cultivated olive). Molecular analyses based on the cytochrome c oxidase subunit coxI and D2-D3 segments of 28S RNA markers showed high diversity and pronounced genetic structure among populations of Rotylenchulus macrosoma. However, the complexity of phylogeographic patterns in plant-parasitic nematodes may be related to the intrinsic heterogeneity in the distribution of soil organisms, a rare occurrence of a species, or the potential human impact associated with agricultural practices.

Summary: Longidorus sanlitanensis n. sp. was recovered from the rhizosphere of Melilotoides ruthenica and Chamaerhodos erecta in the Inner Mongolia Autonomous Region, P.R. China, and was described and illustrated using morphological and molecular data. The new species is characterised by medium body length of females (4.0-4.8 mm), lip region anteriorly rounded and separated from the rest of the body by a depression, pocket-shaped amphidial pouches, the guiding ring located at 58.4-66.0 μm from the anterior end, odontostyle and odontophore 107.2-114.6 and 71.6-77.8 μm long, respectively, the pharyngeal bulb 68.7-79.7 μm long, a short conical tail with a broadly rounded terminus, four juvenile developmental stages (J1 was not detected) and males absent. By similarities in the distance of the guiding ring from the anterior body end, body and odontostyle length and lip region shape, the new species was compared with nine similar species, namely: L. litchi, L. diadecturus, L. fursti, L. himalayensis, L. jonesi, L. wiesae, L. macromucronatus, L. fangi and L. zhengi. The matrix code of the new species is: A4-B2-C5-D4-E1-F2-G2-H12-I2-J1-K?. The phylogenetic relationships of the new species with other relevant species were reconstructed using near-full-length 18S, ITS1 and 28S D2-D3 regions of rRNA gene and the resulted topologies were discussed. In 18S phylogeny, L. sanlitanensis n. sp. formed a clade with L. litchi inside a major clade, including species with a posteriorly located guiding ring, and in 28S phylogeny it showed close relationships with species having a posteriorly located guiding ring. This is the 22nd Longidorus species recorded from China.

Background: Solenopsis invicta, commonly known as the red imported fire ant (RIFA), is an important global invasive pest, and its management is challenging because of insecticide resistance and environmental problems. Methods: In this research, we applied transcriptomics to analyze the molecular responses of S. invicta worker ants exposed to different types of pesticides, beta-cypermethrin (BC) and the entomopathogenic fungus Cordyceps cicadae (CC), as well as to different concentrations of these pesticides. Results: A total of 2727 differentially expressed genes (DEGs) were identified across all samples. The number of DEGs in the BC treatment group was significantly higher than that in the CC treatment group (2520 vs. 433), and higher concentrations resulted in more DEGs (an increase of 47 in the BC group and 229 in the CC group). KEGG pathway analysis revealed that the DEGs were significantly enriched in lipid metabolism, carbohydrate metabolism, amino acid metabolism, signal transduction, and membrane transport. Immune-related gene analysis showed more general down-regulation (average FPKM value in BC 741.37 to 756.06 vs. CK 1914.42) of pathogen recognition genes (PGRP-SC2) under BC stress conditions, while CC treatment resulted in increases in expression of important immune effectors such as various serine proteases. Conclusions: Overall, this study provides useful insights into the molecular basis of responses to different pesticides in S. invicta and offers a basis to develop new approaches to control this pest.

Longidorus zhengi n. sp. was recovered in the rhizosphere of Quercus aliena in China. The new species is characterised by medium-length females (3.2-4.0 mm), lip region slightly offset, anteriorly flat and separated from the rest of the body by constriction, funnel-shaped amphidial pouches, a simple guiding ring located at 57.0-60.0 μm distance from the anterior end, stylet composed of a moderately long odontostyle (108.0-139.0 μm) and weakly developed odontophore (56.0-68.0 μm), 61.0-74.0 μm long pharyngeal bulb, well-developed offset cardia, and a short conical tail with widely rounded terminus. The species has four juvenile developmental stages (J1-J4) and no male was found. The matrix codes of the new species are: A45-B23-C5-D2-E1-F2-G1-H1-I1-J1-K5. The new species was molecularly characterised using ITS1 and 28S D2-D3 rRNA gene sequences. The phylogenetic analyses placed L. zhengi n. sp. with several species described from the mainland of China, which were clustered with L. litchi, L. diadecturus and L. juglans. Longidorus zhengi n. sp. was recovered in the rhizosphere of Quercus aliena in China. The new species is characterised by medium-length females (3.2-4.0 mm), lip region slightly offset, anteriorly flat and separated from the rest of the body by constriction, funnel-shaped amphidial pouches, a simple guiding ring located at 57.0-60.0 μm distance from the anterior end, stylet composed of a moderately long odontostyle (108.0-139.0 μm) and weakly developed odontophore (56.0-68.0 μm), 61.0-74.0 μm long pharyngeal bulb, well-developed offset cardia, and a short conical tail with widely rounded terminus. The species has four juvenile developmental stages (J1-J4) and no male was found. The matrix codes of the new species are: A45-B23-C5-D2-E1-F2-G1-H1-I1-J1-K5. The new species was molecularly characterised using ITS1 and 28S D2-D3 rRNA gene sequences. The phylogenetic analyses placed L. zhengi n. sp. with several species described from the mainland of China, which were clustered with L. litchi, L. diadecturus and L. juglans.