Predatory capability of Eocanthecona furcellata(Hemiptera:Pentatomidae)on the larvae of Spodoptera frugiperda(Lepidoptera:Noctuidae)under semi-field environmental conditions
To scientifically evaluate the predatory capability of the native natural enemy predatory stink bug Eocanthecona furcellata on the larvae of the important agricultural pest fall armyworm Spodoptera frugiperda.The predatory capabilities of the 3 rd and 5th instar nymphs and female adults of E.furcellata on the 3 rd and 5th instar larvae of S.frugiperda were evaluated by using functional response models in net cages.Results showed that the numbers of larvae of S.frugiperda consumed by E.furcellata increased and saturated as the prey density increased,except for the 3rd instar nymph of E.furcellata,which could not prey on the 5th instar larvae of S.frugiperda singly,while the predation rate of E.furcellata decreased with the increase of prey density.Both E.furcellata nymphs and female adults exhibited a type Ⅱ functional response to different instar larvae of S.frugiperda based on Logistic regression equation.Parameters from Rogers'random predator equation showed that,the instantaneous attack rates a of the 3rd and 5th instar nymphs and female adults of E.furcellata on the 3 rd instar larvae of S.frugiperda were 0.0295,0.0453 and 0.0965,respectively,the handling time Th was 3.98 h,1.36 h and 1.21 h,respectively,and the theoretical daily maximum predation T/Th was 6.03,17.65 and 19.83,respectively.The instantaneous attack rates of the 5 th instar nymphs and female adults on the 5th instar larvae of S.frugiperda were 0.0545 and 0.0876,the handling time was 3.67 h and 4.83 h,and the theoretical daily maximum predation was 6.54 and 4.97,respectively.Both the 5 th instar nymphs and female adults of E.furcellata exhibit strong predatory capability on the larvae of S.frugiperda,however,the predation ability of the 3rd instar nymphs was relatively weak.These results provide a practical reference for the rational use of E.furcellata to control S.frugiperda.