Significance: Developmental synchrony, resulting from reduced fluctuation in individual development rate, is critical for swarming, migration, and social relationships of colonial animals. However, the molecular regulators of synchronous development are poorly understood. The migratory locust transits between high-density gregarious and low-density solitarious phases, with the former displaying more synchronous sexual maturation. Here, we identify a microRNA (miRNA), miR-276, expressed in the ovaries of female locusts mediating progeny egg-hatching synchrony by up-regulating its target brahma ( brm ), a transcription coactivator gene. Moreover, this up-regulation was dependent on the secondary structure of brm RNA. Our study demonstrates a noncanonical mechanism of miRNA-mediated gene regulation and provides important traits of locust phase transition for clues of possible prediction of pest plague outbreaks.

The mitochondrial genome of Eysarcoris guttigerus has been decoded using Illumina sequencing. The mitogenomic size is 15,368 bp with 42.97% A, 33.90% T, 13.22% C, and 9.90% G. It encoded 13 protein-coding genes, two ribosomal RNA, and 22 transfer RNAs. Phylogenetic tree showed that genus Eysarcoris had a closer relationship with the genus Carbula than the rest of 20 genera.

Notobitus montanus Hsiao, 1963 is a major pest of bamboos. The mitogenome of N. montanus (ON052831) was decoded using next-generation sequencing. The mitogenome, with 42.26% A, 30.54% T, 16.54% C, and 10.65% G, is 16,209 bp in size. Codon usage analysis indicated that high frequently used codons used either A or T at the third position of the codon. Amino acid usage analysis showed that leucine 2, phenylalanine, isoleucine and tyrosine were the most abundant in 31 Coreoidea species. Thirteen protein-coding genes (PCGs) were evolving under purifying selection, nad5 and cox1 had the lowest and strongest purifying selection stress, respectively. Correlation analysis showed that evolutionary rate had positive correlation with A+T content. No tandem repeat was detected in the non-coding region of N. montanus. The phylogenetic tree showed that Alydidae and Coreidae were not monophyletic. However, the topology of phylogenetic trees, based on 13 PCGs, was in accordance with that of tree based on both mitochondrial and nuclear genes but not ultraconserved element loci or combination of 13 PCGs and two rRNAs. It seems that their relationships are complex, which need revaluation and revision. The mitogenomic information of N. montanus could shed light on the evolution of Coreoidea.

The mitochondrial genome of Melanostoma orientale has been decoded by Illumina sequencing. The mitogenomic size is 16,229 bp with 40.96% A, 40.29% T, 10.60% C, and 8.15% G. It is encoded with 13 protein-coding genes, 2 ribosomal RNA, and 22 transfer RNAs. The phylogenetic tree showed that 10 species of Syrphidae, belonging to six genera, were clustered into two clades. This is the first mitochondrial genome for the genus Melanostoma.