Host selectivity,fitness,and risk analysis of fall armyworm Spodoptera frugiperda to maize and five non-gramineous crops
To the monitor and control fall armyworm Spodoptera frugiperda,feeding and oviposition preferences were tested on maize and five non-gramineous crops using leaf disc and half field simulated selection methods.The development,survival rate,and fecundity of S.frugiperda fed on these crops were determined under indoor conditions,and the fitness of the pest on various plants were evaluated using the population growth trend index.Host selectivity was further verified through field plot experi-ments.The results showed that S.frugiperda had the highest feeding choice rate for maize,followed by peanut and cabbage when maize was available.Without maize,peanut and cabbage had higher feeding choice rates than other plants.The feeding choice rate for eggplant and banana was the lowest,regard-less of maize presence,and decreased over time,with the pest eventually avoiding these plants.The pest exhibited deterrence to eggplant and banana.In terms of oviposition preference with maize available,S.frugiperda laid 2 452.50 eggs on maize,which was 6.29,5.79,and 11.43 times more than on peanut,cabbage,and cowpea,respectively,over a five-day oviposition period of by 12 pairs of adults.Nota-bly,468.25 eggs were laid on mesh rather than on eggplant and banana.Without maize,1 812.50 eggs were laid on mesh,significantly higher than on any of the five non-gramineous crops.It suggests that S.frugiperda may spread to the environment instead of laying eggs on non-preferable host plants when preferred hosts are absent or saturated.Spodoptera frugiperda fed on non-gramineous crops exhibited development retardation and lower survival rate compared to those fed on maize.Spodoptera frugiperda could complete its life cycle on peanut,cabbage,and cowpea,but with relative fitness values of only 0.46,0.07,and 0.04,respectively,compared to the population growth trend index on maize.However,it could not complete its life cycle on eggplant and banana.Field plot experiments confirmed significant differences in host selectivity and adaptability on various crops.In conclusion,S.frugiperda poses a se-vere risk of damage to peanut,a small risk to cabbage and cowpea,and is highly unlikely to damage eggplant or banana.
万方数据
维普
