| Mallada basalis(Walker)is an important natural enemy of many agricultural pests,such as insect scales,mites,aphids,whiteflies,plantlice,etc,which could effectively suppress the pest population growth in orchards and farms.In this paper,Response-Surface Design(RSD)was used to select the optimal artificial diet for M.basalis,and the dried powder of the larvae of Bactrocera dorsalis(Hendel),beef liver,chicken egg yolk,and honey were chose as the main components.Functional response method was used to evaluate the predatory efficiency of M.basalis fed on artificial diets to female adults of Brevicoryne brassica(L.)and Phenacoccus solenopsis Tinsley.The main results are as follows:1.The selection of heterologous protein for artificial diets of Mallada basalisTo select the most effective heterologous protein for artificial diets of Mallada basalis,four types of artificial diets were composed of the dried-powder of the larvae of B.dorsalis(or the dried-powder of the pupae of Antheraea pernyi),beef liver,chicken egg yolk and honey as the main nutrients,and royal jelly,yeast powder,vitamin C,streptomycin sulfate as the helper component.Results showed that each artificial diet could make M.basalis complete its generation development.But the optimal biological characters were observed in the groups fed on artificial diets composed of the dried-powder of the larvae of B.dorsalis and beef liver.Fed on this type artificial diet,the developmental time of the first,second and the third instar larvae of M.basalis were 4.90 d,5.81 d and 5.45 d respectively,and the corresponding survival rate were 98.23%,85.75% and 97.36% respectively.and the survival rate of pupae was 73.23%.The dried-powder of the larvae of B.dorsalis and beef liver will be used as the main heterologous protein for artificial diets in the following experiments.2.Selection dosage form of artificial diets for Mallada basalisThe above-mentioned artificial diets were made into liquid food and semi-solid food by adding agar or not,and use the cotton,biofilm and sponge as the food carrier.Results showed that liquid food carried with biofilm was the most suitable type diet for M.basalis.Fed on this dosage form of artificial diet,the developmental time of the first,second,third larvae andpupae of M.basalis were the developmental time of the first,second and the third instar larvae of M.basalis were 5.10 d,5.23 d,5.45 d and 14.24 d respectively,and the corresponding survival rate were 36.23%,59.54%,75.58% and 89.05% respectively.The liquid food carried with biofilm will be used as the dosage form for artificial diets in the following experiments.3.The optomization of artificial dietsBsed on the selection of heterologous protein and dosage form,a total of 31 groups of artifical diets were designed with RSD in Statistical Analysis System(SAS),the dried-powder of the larvae of B.dorsalis,beef liver,chiccken egg yolk and honey were chose as the main components,royal jelly,yeast powder,vitamin C and streptomycin sulfate were selected as the helper components.According to the main biological characters,such an the developmental duration and survival rate of larvae,preoviposition and oviposition period,percentage of ovipositing female adults,number of eggs produced and hatching rate of the offspring,artificial diet No.23,No.25-No.31 were sorted out as the suitable diets for M.basalis,and the diet No.25 was the best one.Fed on the diet No.25,the development time and survival rate of M.basalis from the second instar larvae to adults,oviposition period,percentage of ovipositing female adults and eggs lied were 16.6 d,36.29 d,93.54% and 449.65,respectively,which was quite close to that of M.basalis fed on eggs of Corcyra cephalonica Stainton(the control group),14.07 d,35.25 d,95.12% and 448.45,respectively.4.Predatory efficiency of Mallada basalis to Brevico brassicae and Phenacoccus solenopsisFunctional response method was used to evaluate the predatory efficiency of M.basalis to B.brassicae and P.solenopsis.Results showed that functional response of the second and third instar larvae of M.basalis to B.brassicae and P.solenopsis were fitted well with Holling ?model.Under the prey(B.brassicae)density of 10,20,30,40,50,60 and 80 per petri dish,the number of prey consumed by the second instar larvae of M.basalis were 6.80,8.80,12.40,15.40,20.00 25.60 and 32.00,respectively,which was a little higher than that in the control group,6.40,7.20,12.00,13.60,20.80,21.80 and 23.00,respectively.Under the prey(B.brassicae)density of 20,30,40,60,80,100 and 120 per petri dish,the number of prey consumed by the second instar larvae of M.basalis were 11.40,19.00,22.00,26.00,31.00 and42.50,respectively,which was close to that in the control group,12.20,16.20,19.60,27.20,35.20,38.80 and 40.40,respectively.Predatory efficiency of the third instar larvae of M.basalis to the female adults of P.solenopsis was quite similar between the artificial diet feeding group and the control,Under the prey(P.solenopsis)density of 3,6,9,12,15 and 18 per petri dish,the number of prey consumed by the third instar larvae of M.basalis were 1.80,2.00,2.20,2.20,3.00 and 3.80,respectively,which was a little higher than that in the control group,6.40,7.20,12.00,13.60,20.80,21.80 and 23.00,respectively,and they were 1.80,2.20,2.40,2.60,3.60 and 4.20,respectively,in the control group.According to the above results,artificial diet No.25 was the suitable food for rearing M.basalis,the key biological characters,such as the developmental rate,survival rate and fecundity were close to the control group.And some biological characters were even better than the control,the predatory capacity of the second and third instar larvae of M.basalis were higher than that of the control group. |
PDF Full Text Request