Study On The Pathogenicity Of Metarhizium Anisopliae To Gynaikothrips Ficorum And Determination Of Its Compatibility With Volatile Compound

Gynaikothrips ficorum（Marchal 1908）（Sanoptera:Phlaeothripida）is one of the major pests of Ficus species.The insect like to hiding in the leaf-roll pseudo-galls caused by their harm together.Because their strong concealment,the insects are difficult to contact with the drug and effect the control.The study were screen the highly pathogenic strain of Metarhizium anisopliae against G.Ficorum.And screened out strong stimulation volatile compound to G.Ficorum by electroantennogram（EAG）test and Y type olfactometer.Furtermore,studied the compatibility of highly pathogenic strain and strong stimulation compound.The Aim was to stimulation and stress G.Ficorum escape from the leaf-roll pseudo-galls and contact with the spores of M.anisopliae after spraying fungus.And return or escape to other threes with spores.If so,the epidemic fungal disease would be induced among the population of G.Ficorum and achieve to control them.The results as follows:1.The virulence of 17 Metarhizium anisopliae strains against G.Ficorum were screened by immersion method.The result indicated that the corrected mortality of G.Ficorum adults and nymphs were 63.89%-100.00%and 38.03%-83.10%after inoculation with（1±0.5）×1O7 spore mL^-1 for 9 days respectively.And the strains of Maxm-05 showed the strongest virulence with the corrected mortality were（100.00±0.00）%and（84.03±5.61）%,the median lethal time（LT50）were（3.86±0.16）d and（4.94±0.39）d,the cadaver rate were（61.03±3.94）%and（75.13±5.15）%,respectively.On the 6th day,the LC50 of Maxm-05 strain to adults and nymphs were 5.720×104 spore·mL^-1 and 1.739×105 spore mL^-1.Analyzed by TDM model,the death peak of the adults and nymphs were 3-7 d and 3-6 d respectively after treatmentthe with Maxm-05 strain.It was proved that the Maxm-05 strain has important application potential in biological control of G.Ficorum.2.In order to optimize the growth nutrition and environmental conditions of the strain Maxm-05,the growth conditions of the strains at 5 different medium and different temperatures were measured.After 10 days of culture,the mycelial growth and sporulation of the strain on PPDA medium were better,the colony diameter reached（31.690±0.89）mm and the Sporulation capacity reached（4.87±0.56）× 106 spore mm-2.Besides,the optimum temperature for the growth and sporulation of this strain was between 25 ℃ and 27 ℃.When the temperature exceeded 30 ℃,the spore germination rate decreased significantly.The optimum temperature for spore germination was 27 ℃.3.The antennal electrophysiology reactions of adult G.Ficorum to 9 volatile compound were measured using the EAG technique.The results showed that at a concentration of 10 μL·mL^-1,the EAG response to N,N-diisopropylethylamine was highest in the adult antennae of G.Ficorum and it increased with the increase of compound concentration,especially within the range of 1 μL·mL^-1 to 10 μL·mL^-1,there was a jump increase with increasing concentrations.It showed that the adult G.Ficorum is highly sensitive to N,N-diisopropylethylamine.4.The insect Y type olfactometer was uesd to test the the behavioral responses of adult G.Ficorum to five concentrations of N,N-diisopropylethylamine.The result showed that each concentration of N,N-diisopropylethylamine had repellent effect on G.Ficorum.The repellent rate was（59.00±2.45）%when the concentration was 1 μL·mL^-1,and the repellency reached（64.00±1.87）%when the concentration was 10μL·mL^-1.The repellent effect becomes larger as the concentration of N,N-diisopropylethylamine increases,consistent with the trend of the EAG test reaction.It showed that N,N-diisopropylethylamine can be used as a repellent against G.Fiicorumto.5.The effects of different concentrations of N,N-diisopropylethylamine on the spore germination rate,colony growth,and sporulation of M.anisopliae strain Maxm-05 were measured and the compatibility was evaluated.The results showed that:when the concentration of N,N-diisopropylethylamine was 10 μL·mL^-1 and 1μL·mL^-1,the spore germination,colony growth and sporulation of M.anisopliae strain Maxm-05 were all strong.Inhibition;when the concentrations were 0.1 μL·mL^-1,0.05 μL·mL^-1,and 0.01 μL·mL^-1,the spore germination,colony growth,and sporulation of M.anisopliae strain Maxm-05 were not significantly different from those in the control group.The result conjunction with the conclusion of the previous section,showed that the concentration of N,N-diisopropylethylamine was controlled during 0.1 μL·mL^-1 to 1 μL·mL^-1 when it mixed with the M.anisopliae strain Maxm-05.