A plant virus satellite RNA directly accelerates wing formation in its insect vector for spread

Cucumber mosaic virus (CMV) often accompanies a short RNA molecule called a satellite RNA (satRNA). When infected with CMV in the presence of Y-satellite RNA (Y-sat), tobacco leaves develop a green mosaic, then turn yellow. Y-sat has been identified in the fields in Japan. Here, we show that the yellow leaf colour preferentially attracts aphids, and that the aphids fed on yellow plants, which harbour Y-sat-derived small RNAs (sRNAs), turn red and subsequently develop wings. In addition, we found that leaf yellowing did not necessarily reduce photosynthesis, and that viral transmission was not greatly affected despite the low viral titer in the Y-sat-infected plants. Y-sat-infected plants can therefore support a sufficient number of aphids to allow for efficient virus transmission. Our results demonstrate that Y-sat directly alters aphid physiology via Y-sat sRNAs to promote wing formation, an unprecedented survival strategy that enables outward spread via the winged insect vector.

Comparative Transcriptomic Analysis of Riptortus pedestris (Hemiptera: Alydidae) to Characterize Wing Formation across All Developmental Stages

Riptortus pedestris (Hemiptera: Alydidae) is a major agricultural pest in East Asia that causes considerable economic losses to the soybean crop each year. However, the molecular mechanisms governing the growth and development of R. pedestris have not been fully elucidated. In this study, the Illumina HiSeq6000 platform was employed to perform de novo transcriptome assembly and determine the gene expression profiles of this species across all developmental stages, including eggs, first-, second-, third-, fourth-, and fifth-instar nymphs, and adults. In this study, a total of 60,058 unigenes were assembled from numerous raw reads, exhibiting an N50 length of 2126 bp and an average length of 1199 bp, and the unigenes were annotated and classified with various databases, such as the Kyoto Encyclopedia of Genes and Genomes (KEGG), Clusters of Orthologous Groups (COG), and Gene Ontology (GO). Furthermore, various numbers of differentially expressed genes (DEGs) were calculated through pairwise comparisons of all life stages, and some of these DEGs were associated with immunity, metabolism, and development by GO and KEGG enrichment. In addition, 35,158 simple sequence repeats (SSRs) and 715,604 potential single nucleotide polymorphisms (SNPs) were identified from the seven transcriptome libraries of R. pedestris. Finally, we identified and summarized ten wing formation-related signaling pathways, and the molecular properties and expression levels of five wing development-related genes were analyzed using quantitative real-time PCR for all developmental stages of R. pedestris. Taken together, the results of this study may establish a foundation for future research investigating developmental processes and wing formation in hemimetabolous insects and may provide valuable data for pest control efforts attempting to reduce the economic damage caused by this pest.

Research on obstacle avoidance technology of fixed wing formation based on improved artificial potential field method with stereo vision

To solve the problem that distributed fixed wing formation cannot know all the other aircraft states through the ground station and may collide, the improved artificial potential field method based on binocular stereo vision was proposed. This method makes the fixed wing aircraft not need to obtain the position information of other fixed wing aircraft from the ground station, but only need the binocular stereo vision module to obtain the relative position and relative speed information of other fixed wing aircraft. These two parameters are used to improve the traditional artificial potential field method to meet the requirements of distributed fixed wing formation flight. The experimental results show that the improved artificial potential field method improves the safety and reliability of distributed fixed wing formation flying.

Comparing the Individual and Combined Effects of Ant Attendance and Wing Formation on Aphid Body Size and Reproduction

Species employ multiple strategies to deal with stressful environments, but these strategies often incur costs. Aphids frequently utilize multiple predator avoidance strategies, including attracting mutualist ants for protection and dispersing by producing winged forms. While both strategies can be physiologically costly, the magnitudes of these costs have not been previously compared. In this study, we experimentally manipulated ant attendance in the field and measured the individual and interactive effects of ant attendance and wing formation on body size and reproduction of the ant-tended aphid Cinara schwarzii (Wilson) (Hemiptera: Aphididae). Aphid adult body size was smaller in the presence of ants (18%), but controlling for body size, there were no differences in embryo number or size. In contrast, wing formation did not affect adult body size but strongly reduced embryo number (46%) and size (8%). Although ant attendance reduced C. schwarzii wing formation, ant attendance and wing formation acted independently on aphid body size and reproduction. For comparison, we confirmed that the manipulation of ant presence had no effect on body size or reproduction of the untended co-existing congener Cinara solitaria (Gillette and Palmer) (Hemiptera: Aphididae). Complementing our empirical study, a meta-analysis of 78 responses from 24 publications showed that wing formation consistently and significantly reduces aphid body size and reproduction (37%), while the effects of ant attendance showed a mean positive effect (9%) that did not significantly differ from zero. Together, our empirical study and meta-analysis provide strong evidence for costs of wing formation but not ant attendance for aphids.