Effects Of Brown Planthopper(BPH) Populations Which Resistance To Imidaclopid On Controlling Potential Capacity And Developing Insecticide Resistance Of Cyrtorhinus Lividipennis(Reuter)

Cyrtorhinus lividipennis (Reuter) is an important natural enemy of Nilaparvata lugens (Stal). The experiment, froming the population of C. lividipennis Fo, keeping with the eggs of BPH that is resistant and susceptible to imidacloprid subculture rearing5generations to getting the colony of RNC F5and SNC F5. Besides, successive to induction resistance of C.lividipennis5generations with the value of LC50to imidacloprid to get the colony of induced F5. On the observation of biological characteristics of RNC and SNC F5, measuring functional response of them, the sensitivity to imidacloprid of various colonys of C.lividipennis is as well as the vitality of EST, GST and MFO. Generally speaking, in order to understand that BPH resistance to imidacloprid how to affect on Cyrtorhinus lividipennis in controlling potential capacity and developing insecticide resistance, the outcome is in the followings:1、The duration of eggs, the first, the fourth and fifth instar nymphs of RNC and SNC F5did not have significant differences. However, duration of the second and the third instar nymphs of SNC F5were4.40and3.65d which were significantly longer than the duration of RNC F5, which were only3.20and3.10d. Duration of the female and the male of RNC F5were24.70and21.13d which were significantly longer than the duration of SNC F5, which were17.50and15.70d. The colony of RNC and SNC F5emergences throughout the day. The peak time of emergence rate is from18pm to8am the next day with the rates of40.00%and37.78%followed by the time between14and16pm with the rates of17.78% and22.23%. The fecundity of daily average, duration of spawning and hatching rate of eggs of RNC and SNC F5did not show the significant differences.2、The predation amount of RNC and SNC F5to prey the number of BPH eggs grows followed by the insect’ ages. The predation amount of the female was more than the male’s. The predation amount of first, second, third and fourth instar nymphs of RNC F5to prey the number of BPH eggs were2.55,3.82,6.78and8.62grains/day, which is significantly higher than SNC F5, which were2.21,2.88,6.12and7.40grains/day, The predation amount of fifth instar nymphs and adult of RNC and SNC F5to prey the number of BPH eggs did not show significant differences. The predation amount of first to fifth instar nymphs of RNC and SNC F5to prey the number of BPH nymphs in increase followed by the insects’ ages, The predation amount of second to fifth instar nymphs of RNC F5to prey the number of BPH nymphs were0.14,0.19,0.35and0.51heads/day, significantly higher than SNC F5, the SNC F5were2.21,2.88,6.12and7.40grains/day. The predation amount of first instar nymphs and adult of RNC and SNC F5to prey the number of BPH nymphs did not show significant differences.3、The functional response of all the instar nymphs and the adults of RNC and SNC F5to BPH eggs with Holling Ⅱ can work out with each other well. The predation amount is increasing with increasing density within a reasonable range. But the increasing is limited. At first instar nymphs, the ability of predation to BPH eggs, maximum predation of daily, instantaneous attack rate and processing time of two colonys did not show significant differences. At second instar nymphs, the maximum predation amount of RNC F5to prey the BPH eggs was5.60grains, which was higher than SNC F5significantly, maximum predation of SNC F5was4.51grains, and the processing time was0.1791d, which was significantly shorter than the processing time of SNC F5. The processing time of SNC F5was0.2224d, however there was no significant differences in the instantaneous attack rate. At third instar nymphs, the maximum predation amount of RNC F5to prey the BPH eggs was11.52grains, which was higher than SNC F5significantly. The maximum predation of SNC F5was10.47grains, and the processing time was0.0876d, which was significantly shorter than the processing time of SNC F5. The processing time of SNC F5was0.0958d. However, there was no significant differences in the instantaneous attack rate. At fourth instar nymphs, the maximum predation of RNC F5to prey the BPH eggs was12.71grains, which was higher than SNC F5significantly. The maximum predation of SNC F5was11.73grains. and processing time was0.0773d, which was significantly shorter than the processing time of SNC F5. The processing time of SNC F5was0.0877d. However, there was no significant differences in the instantaneous attack rate. At fifth instar nymphs, the maximum predation of RNC F5to prey the BPH eggs was13.88grains, which was higher than SNC F5significantly. The maximum predation of SNC F5was12.31grains and the processing time was0.0722d, which was significantly shorter than the processing time of SNC F5. The processing time of SNC F5was0.0814d as well as they were significant differences in the instantaneous attack rate. The instantaneous attack rate of RNC and SNC F5were1.3884and2.1087. At adult, the ability of predation amount to BPH eggs, maximum predation of daily, instantaneous attack rate and processing time of two colonys did not show significant differences.4^The imidacloprid values of LC50on C.lividipennis F0was20.9631mg a.i.L-1. The imidacloprid values of LC50on RNC and SNC F5were22.1548and20.0414mga.i.L-1. The imidacloprid values of LC50on induction F5was23.6475mga.i.L-1. The sensitivity to imidacloprid of induction F5which had been inductioned by imidacloprid was the lowest. The sensitivity to imidacloprid of SNC F5was the highest.5、 After5generations when C.lividipennis had been feeded with the BPH eggs of anti-sense imidacloprid the EST and MFO vitality of RNC F5were0.3175μmolmin-1mg1and0.0166nmolmin-1mg1. F0、SNC F5and induction F5did not show significant differences comparing with it.The GST vitality of RNC F5with enzymatic reaction substrate of DCNB was0.0116ΔOD min-1mg-1, which was significantly higher than Fo. It compared with the GST activity of SNC F5and induction F5were not significant differences. The GST vitality of RNC F5which it react with enzymatic reaction substrate of CDNB was0.0018ΔOD min-1mg-1, which was significantly higher than Fo and SNC F5. It compared with the GST activity of induction F5did not show significant differences. The GST vitality with enzymatic reaction substrate of CDNB was lower than the GST vitality with enzymatic reaction substrate of DCNB.