Noctuidae is known to have high species diversity, although the genomic diversity of Noctuidae species have not been studied extensively. Investigation of transposable elements (TEs) in this family can improve our understanding on the genomic diversity of Noctuidae. In this study, we annotated and characterized genome-wide TEs in ten noctuid species belonging to seven genera. With multiple annotation pipelines, we constructed a consensus sequence library containing 1,038 –2,826 TE consensus. The genome content of TEs showed high variation in the ten Noctuidae genomes, ranging from 11.3% to 45.0%. The relatedness analysis indicated that the TE content, especially the content of LINEs and DNA transposons, are positively correlated with the genome size (r=0.86, p-value=0.001). We identified SINE/B2 as a lineage-specific subfamily in Trichoplusia ni, a species-specific expansion of LTR/Gypsy subfamily in Spodoptera exigua, and a recent expansion of SINE/5S subfamily in Busseola fusca. We further revealed that of the four TE classes, only LINEs showed phylogenetic signal with high confidence. We also examined how the expansion of TEs contributed to the evolution of noctuid genomes. Moreover, we identified a total of 56 horizontal transfer TE (HTT) events among the ten noctuid species and at least three HTT events between the nine Noctuidae species and 11 non-noctuid arthropods. One of HTT events caused by a Gypsy transposon might have caused the recent expansion of Gypsy subfamily in the S.exigua genome. By determining the TE content, dynamics, and HTT events in the Noctuidae genomes, our study emphasized that TE activities and HTT events had substantial impacts on the Noctuidae genome evolution.

The alien invasive insect pest Spodoptera frugiperda Smith (Lepidoptera: Noctuidae), commonly referred to as Fall Armyworm (FAW), is a polyphagous insect feeding on more than 350 host plants in addition to maize in its native habitat. Due to the voracious nature of FAW, significant yield losses on maize production were reported across the African continent since its detection in 2016. Despite being a polyphagous insect, little is known about its alternative host plants in the new habitat including Mozambique. This study aimed to assess the host range of FAW in the central province of Manica, Mozambique. A field survey was conducted from May to August 2019 (dry season of 2018/2019 cropping season) and in December 2019 and January 2020 (rainy season of 2019/2020 cropping season) in maize fields and crops often mixed with maize or located in the vicinity of maize fields. A total of 1291 fields were surveyed. In each field, 20 plants were selected in a “W” pattern and checked for the presence of FAW egg masses and/or larvae. At the time of the sampling, no evidence was found suggesting that in Manica province FAW feeds in crops other than maize because out of 35 different crops surveyed, FAW was only recorded on maize. Results from this study suggest that the strain of FAW occurring in Manica province might be the one specialized in maize or the continuous availability of maize fields throughout the year is influencing the choices of the host plants of this invasive insect pest.