| Frankliniella occidentalis（Pergande）is a worldwide agricultural pest that poses a great threat to a variety of vegetables,flowers and other economical crops.Orius similis Zheng is an important predator of F.occidentalis.Calcium ion is one of the necessary nutrient elements for plant growth,and it is also the second messenger trigged by external stimulation,which is involved in the transduction of many signals and plays an important role in regulating the physiological and biochemical activities of plant cells.In this study,Ca Cl2 was chosen as the exogenous inducer,and kidney bean plants-F.occidentalis-O.similis were used as the research system.Firstly,the differences in the contents of secondary substances in the leaves of kidney bean plants pretreated with exogenous calcium with or without F.occidentalis feeding stress were compared.The changes of the pupation rate,pupal weight,detoxification and digestive enzyme of F.occidentalis were determined.The behavioral responses of F.occidentalis and its natural enemy O.similis were also assessed.GC-MS was used to analyze the constituents and contents of volatile compounds in kidney bean plants,and to detect the behavior reaction of F.occidentali and O.similis to volatile compounds.This study will provide a theoretical basis for the prevention and control of F.occidentalis by using exogenous calcium as an inducible factor.The main research results were as follows:1 The effects of exogenous calcium induction on the contents of secondary substances of kidney bean plants,detoxifying enzymes,digestive enzymes and pupae of F.occidentalisAfter spaying 20 mmol/L Ca Cl2,the contents of secondary substances in the leaves of kidney bean plants changed significantly,and the activities and expression levels of detoxification enzyme and digestive enzyme,pupation rate and pupa weight changed too after F.occidentalis feeding.The results showed that:（1）Exogenous calcium significantly induced the accumulation of tannin,flavonoids,total phenols,alkaloids and lignin in the leaves of kidney bean plants,and the changes of the contents of various secondary substances were more obvious under the feeding stress of F.occidentalis.（2）Compared with the kidney bean plants treated with H2O,the activities of GSTs in F.occidentalis increased significantly at 24and 48 h,by 18.97%and 18.39%.P450 increased by 20.90%only at 48 h.Car E activity decreased significantly at 24 and 48 h,by 23.91%and 26.42%,respectively.The activities of GSTs and P450 enzyme significantly decreased with time extension in both treatment of H2O and Ca Cl2.（3）After feeding Ca Cl2 treated plants,the activity of digestive enzymeα-amylase in F.occiduralis significantly increased at 24 and 48 h,by 16.67%and 37.50%,respectively,compared with plants treated with H2O.the activities of chymotrypsin and lipase increased significantly at 48 h,increasing by 37.00%and 31.31%.（4）Compared with the H2O treated kidney bean plants,the expression levels of detoxification enzyme GSTs gene CL992.contig6,the detoxification enzyme P450 gene CYP4-1 and CYP4-2 increased significantly at 24 and48 h after feeding Ca Cl2 treated plants,which was 1.91,2.69,2.22,1.87,2.88 and 3.45 times of that feeding H2O treated plants.Similarly,the expression levels of digestive enzymeα-amylase gene Fo AMY-1 significantly increased at 24 and 48 h,which was 1.17 and 2.04 times.（5）Compared with the H2O treated plants,the pupation rate of the second instar larvae of F.occidentale fed on Ca Cl2 treated plants decreased from 74.86%to 62.57%.The weight of pupa decreased by 22.68%.2 Effects of exogenous calcium induction on the volatiles of kidney bean plants,behavioral responses of F.occidentalis and O.similis（1）The effects of exogenous calcium induction on the behavioral responses of F.occidentalis and O.similis were detected by"Y"type olfactory apparatus.The results showed that kidney bean plants treated by Ca Cl2 and H2O had no effect on behavioral response of F.occidentalis and O.similis in the absence of feeding stress of F.occidentalis.Under the feeding stress of F.occidentalis,the kidney bean plants treated with Ca Cl2 could significantly repelled F.occidentalis and attracted the O.similis.（2）Compared with kidney bean plants treated with Ca Cl2,F.occidentalis significantly preferred kidney bean plants treated by H2O and laid more eggs.The predation rate of O.similis on the Ca Cl2 treated plants was 55.8%at48 h,which was significantly increased by 8.80%compared with the H2O treated plants.（3）The volatiles released by kidney bean plants under different treatments were detected by GC-MS.The results showed that there were 35,40,40 and 42 kinds of volatiles were detected on H2O treatment,Ca Cl2 treatment,H2O+thrips feeding treatment,Ca Cl2+thrips feeding treatment,respectively.Ca Cl2 treatment significantly changed the contents of（E）-2-hexene-1-ol,1-octene-3-ol,β-lonone and（E,E）-2,4-hexadienal.Regardless of feeding stress of F.occidentalis,contents of（E）-2-hexene-1-alcohol and 1-octene-3-alcohol significantly decreased in kidney bean plants treated with Ca Cl2,while percentage contents ofβ-lonone and（E,E）-2,4-hexadienal significantly increased compared with H2O treatment.3 The preferences of F.occidentalis and O.similis to different volatile compounds in kidney bean plantsA six-arm olfactory instrument and a"Y"olfactory instrument were used to furtherly verify the effects of four volatiles（E）-2-hexene-1-ol,1-octene-3-ol,β-lonone and（E,E）-2,4-hexadienal,significant changing proportional composition,on the behavioral responses of F.occidentalis and O.similis.The results showed that:（1）The concentration of（E）-2-hexene-1-alcohol repelling F.occidentalis was 10-1μL/μL,and the concentration to attract O.similis was 10-3μL/μL;1-octene-3-ol had repellent effect on F.occidentalis at the concentration of10-2μL/μL,and was able to attract O.similis at the concentration of 10-2 and 10-3μL/μL.β-lonone had repellent effects on F.occidentalis at concentrations of 10-1 and 10-2μL/μL,and attractive effects on O.similis was at concentrations of 10-2 and 10-3μL/μL.（E,E）‐2,4‐hexadienal at concentrations of 10-1～10-4μL/μL repelled F.occidentalis and attracted O.similis at concentrations of 10-5μL/μL.（E,E）‐2,4‐hexadienal at concentrations of 10-1～10-4μL/μL repelled F.occidentalis and attracted O.similis at concentrations of 10-3and 10-5μL/μL.Among them,10-2μL/μL of 1-octene-3-ol,10-2μL/μL ofβ-lonone and 10-3μL/μL of（E,E）-2,4-hexadienal could both repel F.occidentalis and attract O.similis.（2）Further comparison with a"Y"olfactory test showed that 10-2μL/μL of 1-octene-3-ol,10-2μL/μL ofβ-lonone and 10-3μL/μL of（E,E）-2,4-hexadienal were repellent to F.occidentalis and attractive to O.similis,compared with clean air.The 1-octene-3-ol repellent effect of F.occidentalis was stronger than that ofβ-lonone,and was more attractive to the O.similis than（E,E）-2,4-hexadienal. |
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