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The oriental armyworm, Mythimna separata (Walker, 1865) (Lepidoptera: Noctuidae), is a serious global migratory insect pest of grain crops. Although its migratory biology has been studied for a long history, the factors affecting wingbeat frequency (WBF), which is closely related to the flight activity of the insect, remain unclear. In this study, the WBFs of both cultured and migrating moths were tested under different conditions in the laboratory using a stroboscope. The results indicated that age and mating status significantly influenced WBF. One day old adults had the lowest WBF, and unmated females had a significantly higher WBF than that of mated females. In general, the WBF of males was significantly higher than that of female individuals. The WBF decreased gradually with increasing environmental humidity, and WBF had a significant negative binomial regression relationship with temperature change. The WBF of moths that fed on hydromel was much higher than those of the controls that fed on water or without diet. However, wind speed and air pressure had no significant effects on the moth WBF in the test environments. These findings provide a deeper understanding of factors that affect flight ability in M. separata , which will be helpful for developing a regional migratory monitoring and warning system of the pest, such as identifying target insect species based on the WBF from radar observation. [ABSTRACT FROM AUTHOR]

The codling moth Cydia pomonella is a major pest of global significance impacting pome fruits and walnuts. It threatens the apple industry in the Loess Plateau and Bohai Bay in China. Sterile insect technique (SIT) could overcome the limitations set by environmentally compatible area-wide integrated pest management (AW-IPM) approaches such as mating disruption and attract-kill that are difficult to suppress in a high-density pest population, as well as the development of insecticide resistance. In this study, we investigated the effects of X-ray irradiation (183, 366, 549 Gy) on the fecundity and fertility of a laboratory strain of C. pomonella , using a newly developed irradiator, to evaluate the possibility of X-rays as a replacement for Cobalt60 (60Co- γ) and the expanded future role of this approach in codling moth control. Results show that the 8th-day is the optimal age for irradiation of male pupae. The fecundity decreased significantly as the dosage of radiation increased. The mating ratio and mating number were not influenced. However, treated females were sub-sterile at a radiation dose of 183 Gy (20.93%), and were almost 100% sterile at a radiation dose of 366 Gy or higher. Although exposure to a radiation dose of 366 Gy resulted in a significant reduction in the mating competitiveness of male moths, our radiation biology results suggest that this new generation of X-ray irradiator has potential applications in SIT programs for future codling moth control. [ABSTRACT FROM AUTHOR]

Background: The fall armyworm (FAW) Spodoptera frugiperda Smith (Lepidoptera: Noctuidae) invaded Myanmar and China in 2018 and greatly impacted agricultural production and ecosystem balance in these areas. FAW is a migratory insect, but its seasonal migration pattern between the two countries has been largely unknown. From 2019 to 2021, we monitored the seasonal migration of FAW in the China–Myanmar border area using a searchlight trap, assessed the reproductive development status of female migrants and traced the migratory routes by trajectory simulation. Results: FAW moths were trapped by the searchlight trap in Lancang County (Yunnan, China) all year, with obvious seasonal differences in the number caught. There were small‐scale persistent trapping peaks in spring and summer, and obvious peaks in autumn; only a small number of moths were trapped in winter. Examination of the ovaries of female moths collected in different seasons showed that most females had matured, indicating that the moths were migrating and did not take off from the local area. In the migration trajectory simulation, FAW mainly migrated from Myanmar to Southwest China in spring and summer and back to Myanmar in autumn. Conclusion: Our findings indicate that FAW migrates between China and Myanmar according to the monsoon circulation, which will help guide cross‐border regional monitoring and management strategies against this pest. © 2022 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Background: The sterile insect technique (SIT), involving the rearing of larvae for pupation followed by irradiating pupae, is employed for environmentally friendly invasive pest management. Despite its effectiveness, the cost of pupae production poses challenges for small farmers in developing countries. Alternatively, utilizing insect trapping techniques can capture abundant adult insects in their natural habitats, but application potential of adult SIT approach remains unclear., Results: We used the invasive pest Spodoptera frugiperda (Lepidoptera: Noctuidae) to assess the effectiveness of X-ray irradiated moths on their sterility rates, mating competitiveness, flight ability, and larval control efficiency in the field. Our findings revealed that optimal X-ray doses for 1-, 3-, and 5-day-old adult S. frugiperda were 154, 173, and 180 Gy, respectively. These doses rendered males more than 80.0% infertile and females nearly completely infertile. Significantly, the flight ability of sterilized males remained unaffected by sub-sterilizing doses of irradiation. Furthermore, in a release ratio of 16:1:1 (irradiated males-unirradiated males-unirradiated females), irradiated males exhibited the highest mating competitiveness (0.79). In the field-cage experiments, the corrected leaf protection rate and the corrected population decline rate in the 16:1:1 release plot were 60.50% and 74.21%, respectively., Conclusion: These findings suggest that radiation-induced sterility in adult S. frugiperda holds promise for practical applications, offering a conceptual framework and novel approaches for advancing radiation-based pest control technology. © 2024 Society of Chemical Industry., (© 2024 Society of Chemical Industry.)