Three new species of the Sequester group of Pteromalus (Habrocytus) (Hymenoptera: Pteromalidae: Pteromalinae), Pteromalus (Habrocytus) boleensis Yan et Li sp. nov., Pteromalus (Habrocytus) longepedicelus Yan et Li sp. nov., and Pteromalus (Habrocytus) robustus Yan et Li sp. nov. are described and illustrated based on adult morphology and molecular data from Xinjiang, China. The DNA barcodes (ITS2) of Pteromalus (Habrocytus) boleensis sp. nov. and Pteromalus (Habrocytus) robustus sp. nov. have been generated and compared with all existing sequences of the Sequester species group. The results of morphological taxonomy and molecular identification are consistent. A key to all known species of the Sequester group in the world is provided.

Background: Number of investigations, which are focused on arbuscular mycorrhiza fungi (AMF) biodiversity is still limited. The analysis of AMF taxa in the North Caucasus, a temperate biodiversity hotspot, used to be limited by the genera level. The aim of this study was to define AMF biodiversity at the species level in the North Caucasus biotopes. Methods: Molecular genetic identification of fungi was carried out with ITS1 and ITS2 regions as barcodes, sequencing by Illumina MiSeq, analysis of phylogenetic trees for individual genera, searching the operational taxonomic units (OTUs) with identification at the species level. Sequences from MaarjAM and NCBI GenBank were used as references. Results: We analyzed >10 million reads in soil samples for 3 biotopes to estimate fungal biodiversity. 50 AMF species from 20 genera were found. The valley biotopes (disturbed ecosystems, grasslands) were characterized by a greater AMF diversity, as well as the number of OTUs and species, in comparison with the forest biotopes. Conclusion: Our hypothesis is that high AMF biodiversity for the river valley can be associated with a higher percentage of annual plants in these biotopes, as well as with the active development of restorative successional processes.

Stevia rebaudiana (Bert.) is a natural sweetener with diterpenic glycosides, offering 300 times more sweetness than sucrose, and boasting low-calorie content, along with medicinal and therapeutic properties. To address a limited genetic diversity, a germplasm bank comprising 115 segregated lines of stevia was established in Colombia. Notwithstanding, the fungus Athelia rolfsii adversely impacted key stevia lines, leading to wilting and plant mortality. For this reason our study aimed to explore the biocontrol potential of native strains of Trichoderma spp., isolated from productive lots in Colombia's Cordoba department, as a solution to manage A. rolfsii. Soil samples underwent serial dilution technique (103 conidia.mL-1) to obtain Trichoderma spp. isolates, which were thoroughly morphologically and molecularly characterized. A total five native strains were identified through sequencing the PCR products using universal ITS primers, and comparisons with the GENBANK database confirmed their identity (OK310695.1, ON237703.1, ON238106.1, ON237737.1, and ON237923.1). Their biocontrol efficacy against A. rolfsii was evaluated using the dual culture technique. Remarkably, all strains exhibited significant biocontrol capacity against the A. rolfsii isolate INVEPAR-05 (OK271308.1), except for Trichoderma viride INVEPAR-T10 (ON237923.1). These findings suggest that Trichoderma spp. could be a potential option to manage the fungus in stevia.