Nearly complete genome sequences of the first two identified Colorado potato beetle viruses.

The Colorado potato beetle is one of the most devastating potato pests in the world. However, its viral pathogens, which might have potential in pest control, have remained unexplored. With high-throughput sequencing of Colorado potato beetle samples derived from prepupal larvae which died from an unknown infection, we have identified two previously unknown RNA viruses and assembled their nearly complete genome sequences. The subsequent genetic and phylogenetic analysis demonstrated that the viruses, tentatively named Leptinotarsa iflavirus 1 and Leptinotarsa solinvi-like virus 1, are the novel representatives of the Iflaviridae and Solinviviridae families, respectively. To the best of our knowledge, these are the first sequencing-confirmed insect viruses derived from Colorado potato beetle samples. We propose that Leptinotarsa iflavirus 1 may be associated with a lethal disease in the Colorado potato beetle.

An Experimental Study on Colorado Potato Beetle Hibernation Under Natural Conditions.

One of the major pests of potato Solanum tuberosum L. in the temperate zone is the insect Colorado potato beetle (CPB). Most studies on the immunity and diseases of the CPB are conducted during active feeding stages. Nonetheless, there are fewer studies on resting stages, although these beetles spend most of their life cycle in a state of winter diapause (hibernation). In this work, a method for investigating CPB hibernation under natural conditions was developed and tested, offering an opportunity to collect a sufficient number of individuals in winter. In this article, CPB survival was assessed, and infectious agents at different stages of hibernation were identified. CPB mortality increased during the hibernation, reaching a maximum in April-May. Entomopathogenic fungi (Beauveria, Isaria, and Lecanicillium) and bacteria Bacillus, Sphingobacterium, Peribacillus, Pseudomonas, and Serratia were isolated from the dead insects. The survival rate of the beetles for the entire hibernation period was 61%. No frozen or desiccated beetles were found, indicating the success of the presented method.

The Metagenomic Analysis of Viral Diversity in Colorado Potato Beetle Public NGS Data.

The Colorado potato beetle (CPB) is one of the most serious insect pests due to its high ecological plasticity and ability to rapidly develop resistance to insecticides. The use of biological insecticides based on viruses is a promising approach to control insect pests, but the information on viruses which infect leaf feeding beetles is scarce. We performed a metagenomic analysis of 297 CPB genomic and transcriptomic samples from the public National Center for Biotechnology Information Sequence Read Archive (NCBI SRA) database. The reads that were not aligned to the reference genome were assembled with metaSPAdes, and 13314 selected contigs were analyzed with BLAST tools. The contigs and non-aligned reads were also analyzed with Kraken2 software. A total of 3137 virus-positive contigs were attributed to different viruses belonging to 6 types, 17 orders, and 32 families, matching over 97 viral species. The annotated sequences can be divided into several groups: those that are homologous to genetic sequences of insect viruses (Adintoviridae, Ascoviridae, Baculoviridae, Dicistroviridae, Chuviridae, Hytrosaviridae, Iflaviridae, Iridoviridae, Nimaviridae, Nudiviridae, Phasmaviridae, Picornaviridae, Polydnaviriformidae, Xinmoviridae etc.), plant viruses (Betaflexiviridae, Bromoviridae, Kitaviridae, Potyviridae), and endogenous retroviral elements (Retroviridae, Metaviridae). Additionally, the full-length genomes and near-full length genome sequences of several viruses were assembled. We also found sequences belonging to Bracoviriform viruses and, for the first time, experimentally validated the presence of bracoviral genetic fragments in the CPB genome. Our work represents the first attempt to discover the viral genetic material in CPB samples, and we hope that further studies will help to identify new viruses to extend the arsenal of biopesticides against CPB.

An Evaluation of Common Cordyceps (Ascomycetes) Species Found in Chinese Markets.

The common Cordyceps (more than 20 species) found in Chinese markets are evaluated and illustrated. We systematically introduce their taxonomies, allied species, hosts, distributions, yields, selling statuses, and market prices. We summarize and comment on the medicinal value and food safety of Cordyceps. The concept of "cordyceps" is explained, the "best" cordyceps is explored, and Chinese cordyceps culture is analyzed. We suggest using the word "cordyceps" instead of the Latin Cordyceps to report these important edible and medicinal mushrooms.