Densoviruses (DVs) are a group of viruses that contain a linear single-stranded DNA genome between 4–6 kb in length. Herein, we report a DV with a 5,480-nt genome, isolated from tobacco aphid (Myzus persicae nicotianae Blackman), named MpnDV. Unlike the genome of M. persicae densovirus (MpDV), which possesses five open reading frames (ORFs), the genome of MpnDV contains four putative ORFs—the nonstructural protein 1 (NS1) and NS2 from MpnDV are 98 - and 52-amino acids longer than those of MpDV, respectively, at the N-terminus, and the capsid proteins (VP) are 102 amino acids longer at the C-terminus than those of MpDV. Mapping of the MpnDV transcripts by RACE method indicated that the ORF of NS2 started at nt 340 and the right two putative ORFs were combined together by deleting two introns, one of 95 bp located at nt 2,932–3,026 and the other of 145 bp located at nt 4,715–4,859, suggesting transcript mapping was necessary for analyzing of genome organization. Alignment analysis indicated that MpnDV shows 97% sequence identity with MpDV, and that the shortened ORFs resulted from nucleotide indels, suggesting MpnDV and MpDV were two isolates of the same virus. Thus, MpnDV and MpDV clustered together in a tree-based analysis. The prevalence of MpnDV infection in wild populations of tobacco aphids differed among 29 locations; 34% of the 622 individuals sampled were positive. The genome organization, transcript strategy, and widespread distribution in wild populations suggest that MpnDV might possess a biological function different from that of MpDV.

Numerous studies focused on drug discovery perspective have proved the great potential for exploration of marine-derived fungi to seek bioactive chemicals. Yet, marine-derived fungi are less explored compared to their terrestrial counterparts. Here, 181 fungal strains (134 species) isolated from marine algae and sediment in Chinese intertidal zones were screened to reveal bioactivities using brine shrimp, green peach aphid and plant pathogens as targets. Fermentation supernatants of 85 fungal strains exhibited a high lethality (>70%) of brine shrimp at 24 h, and 14 strains appeared to be acute-toxic as featured by more than 75% mortality at 4 h, indicating efficient insecticidal bioactivity. The crude extracts of 34 strains displayed high toxicity to green peach aphid with more than 70% of mortality at 48 h. For the plant pathogens tested, the inhibitory rates of eight fungal strains affiliated with Alternaria (AS3, AS4), Amphichorda (AS7), Aspergillus (AS14), Chaetomium (AS21), Penicillium (AS46), Purpureocillium (AS55) and Trichoderma (AS67) were equal or higher than that of the positive Prochloraz, and five of them (AS7, AS14, AS21, AS55, AS67) were also strongly toxic to brine shrimp or aphid. Our findings indicate broad potential for exploration of marine-derived fungi as candidate resources to pursue bioactive compounds in controlling agricultural pests and pathogens.

The devastating impact of chemical pesticides has prompted a shift towards sustainable agricultural pest management, such as biological control with natural enemies. In recent years, commercialization advancements have enabled the suppression of pest populations through augmentative releases of biological control agents, with natural enemies being a major tactic. China has successfully implemented natural-enemy-based biocontrol strategies, particularly for controlling aphids and lepidopterans. This article provides a comprehensive overview of the state-of-the-art natural-enemy-based biocontrol against arthropod pests in tobacco in China, including practical achievements in mass-rearing methods, augmentative release strategies, and the wide-scale use of natural enemies. Current and potential future challenges for natural-enemy-based biocontrol in China are also discussed.

Myzus persicae (Sulzer) is a globally important agricultural pest and a vector of numerous plant viruses. However, its potential global distribution under future climate change remains insufficiently quantified. In this study, we used 5531 occurrence records, six key bioclimatic variables, and an ENMeval-optimized maximum entropy (MaxEnt) model to predict the global habitat suitability of M. persicae. Predictions were made under current climatic conditions and two future Shared Socioeconomic Pathway (SSP) scenarios, SSP1-2.6 (SSP126) and SSP5-8.5 (SSP585), for the 2030s and 2050s. The model showed acceptable discriminatory performance, with a mean training AUC of 0.853, while four-fold spatial block validation produced a mean validation AUC of 0.874 ± 0.044. The mean temperature of the coldest quarter (Bio11) was the most influential predictor, showing a strong association between winter temperature and the predicted suitability of M. persicae. Under current climatic conditions, highly suitable habitats were concentrated mainly in temperate and subtropical agricultural regions. Future projections indicated an overall expansion of suitable habitats and a general tendency toward higher latitudes, with the greatest expansion of highly suitable habitat occurring under SSP126 in the 2050s. Conversely, suitability declined in some tropical and subtropical regions, suggesting that stronger warming may partly offset suitability gains at lower latitudes. These findings suggest that the projected changes in the climatic suitability of M. persicae may not be proportional to warming intensity and may inform global potential climatic risk assessment and climate-adaptive pest management.