Survival Adaptability and Damage Potential of Spodoptera frugiperda in the Soybean-Maize Strip Intercropping
[Objective]This study aims to investigate the feeding metabolic characteristics and migration behavior of Spodoptera frugiperda on soybean and maize,as well as to clarify the feeding rules and potential damage risks of S.frugiperda in the soybean-maize strip intercropping.[Method]The host plants were Xudou 18 and Jiangyu 877,which were recommended for soybean-maize strip intercropping planting in Jiangsu Province.The effects of soybean leaves and maize leaves on feeding preference,growth,oviposition quantity,oviposition selectivity,digestive enzyme activity and digestive metabolism of S.frugiperda were determined by laboratory tests.Field inoculation experiment was conducted to investigate the migration distance and range of S.frugiperda over time under the"2+4"intercropping of maize and soybean,and the potential risk of damage was evaluated based on the migration dynamics.[Result]S.frugiperda exhibited a clear preference for feeding on maize leaves,with 63.89%of individuals selecting to feed on maize leaves,which was 1.77 times higher than the number of individuals that selected to feed on soybean leaves,and the difference was significant.S.frugiperda could complete its life cycle by feeding on both soybean leaves and maize leaves,but the larval development period of those feeding on maize leaves was 14.82 d,which was 2.54 d shorter than those feeding on soybean leaves.The single female fecundity of S.frugiperda feeding on maize leaves was 679.50 eggs,which was significantly increased by 26.58%compared to feeding on soybean leaves.Adult females preferred to oviposit on maize leaves,with the average egg mass number and single female oviposition of 5.67 masses and 521.67 eggs,respectively,which were 1.70 and 2.04 times higher than those on soybean,and the differences were significant.The lipase activity of S.frugiperda feeding on soybean leaves was 9.84 U·g-1,significantly higher than that of those feeding on maize leaves(6.47 U·g-1),while there was no significant difference in protease and amylase activities between the two.The approximate digestibility of S.frugiperda feeding on soybean leaves was 63.40%,which was significantly lower than that of those feeding on maize leaves(69.26%).However,there was no significant difference in food utilization efficiency,food conversion efficiency,and relative growth rate between the two.Field investigations after egg mass inoculation revealed that in the"2+4"strip intercropping pattern of maize and soybean,S.frugiperda primarily infested the maize plants,exhibiting"vertical migration"within the maize rows,and did not spread to the neighboring soybean plants.[Conclusion]S.frugiperda exhibited distinct differences in feeding adaptation and oviposition preference between soybean and maize,displaying a stronger preference and utilization ability for maize compared to soybean.Under the"2+4"strip planting pattern of maize and soybean,S.frugiperda primarily inflicted damage on maize.Therefore,in practical agricultural production,it is crucial to enhance monitoring and control measures for S.frugiperda,particularly during the critical growth stages of maize,to mitigate the risk of damage.
万方数据
维普
