Ary Hoffmann

and 5 more

Conservation research is dominated by vertebrate examples but the shorter generation times and high local population sizes of invertebrates may lead to different management strategies. Here we investigate the genetic structure of an endangered flightless grasshopper, Keyacris scurra, used in classical evolutionary studies in the 60s. It had a wide distribution across New South Wales (NSW) and Victoria in pre-European times but has now become threatened because of land clearing for agriculture. We revisited remnant sites of K. scurra, with populations now restricted to only one area in Victoria and a few small patches in NSW and the Australian Capital Territory (ACT). Using DArTseq to generate SNP markers as well as mtDNA sequence data, we show that the remaining Victorian populations in an isolated valley are genetically distinct from the NSW populations and that all populations are genetically unique, with large FST values up to 0.8. We also find that, with one exception, the NSW/ACT populations separate genetically into chromosomal races (2n = 15 vs. 2n = 17). Isolation by distance was detected across both the SNP and mtDNA data sets, and there was substantial differentiation within chromosomal races. Genetic diversity as measured by heterozygosity was not correlated with the size of remaining habitat patches, with high variation present in some remnant cemetery sites. However, inbreeding correlated negatively with estimated habitat size at 25-500 m patch radius. These findings emphasize the importance of small fragments in conserving genetic variation across the species, and they highlight populations suitable for future translocations.

Li-Jun Cao

and 7 more

The peach fruit moth (PFM), Carposina sasakii Matsumura, is a major phytophagous orchard pest widely distributed across Northeast Asia. Here, we report the chromosome-level genome for the PFM, representing the first genome for the family Carposinidae, from the lepidopteran superfamily Copromorphoidea. The genome was assembled into 404.83 Mb sequences using PacBio long-read and Illumina short-read sequences, including 275 contigs, with a contig N50 length of 2.62 Mb. All contigs were assembled into 32 linkage groups assisted by the Hi-C technique, including 30 autosomes, a female-specific W chromosome and a Z chromosome. BUSCO analysis showed that 98.2% genes were complete and 0.4% of genes were fragmented, while 1.4% of genes were missing in the assembled genome. In total, 23,218 protein-coding genes were predicted, of which 82.72% were functionally annotated. Because of the importance of diapause triggered by photoperiod in PFM, five circadian genes in the PFM as well as in the other related species were annotated, and potential genes related to diapause and photoperiodic reaction were also identified from transcriptome sequencing. In addition, manual annotation of detoxification gene families was undertaken and showed a higher number of ABC and GST genes in PFM than in most other lepidopterans, in contrast to a lower number of UGT genes, suggesting different detoxication pathways in this moth. The high-quality genome provides a resource for comparative evolutionary studies of this moth and its relatives within the context of radiations across Lepidoptera.

Melissa Carew

and 3 more