Study On The Harm Of Pseidailacaspis Pentagona To Pueraria Thomsonii And Its Control

Pueraria thomsonii used for food and medicinal,with roots as the main part for using,is an agricultural product with higher economic value.Guangdong Gaoming is one of its main producing areas,because of its excellent quality sold at home and abroad.pueraria lobata easy to save,so farmers store it in the shed,sold in batches to avoid low prices by focus on the market.In recent years in Gaoming,Pseudaulacaspis pentagona emerged and increasingly spread in the storage of P.thomsonii,its serious damage to the quality of P.thomsonii in storage.There has been no report on the investigation of P.pentagona.So,in this paper,we investigated the source,the occurrence and the damage of P.pentagona on the storage of P.thomsonii as well as the occurrence and the damage of P.pentagona in the farm in Gaoming,and selected five kinds medicine to prevent and cure the P.pentagona during the P.thomsonii storage period and P.thomsonii growth period for efficacy test.the result of research as follows :1.The Features of Occurrence and Damage of P.pentagona in P.thomsonii storageThe Occurrence and Damage of P.pentagona in P.thomsonii storage begin in March,reach in the peak in June until to the P.thomsonii sold out in July to August.At the beginning period of the occurrence of P.pentagona in the shed in P.thomsonii storage appear as the shape of spot,with the larva number of P.pentagona was great increased after several weeks,then the patchy patches were formed.In April 2014,the incidence of the occurrence of P.pentagona in P.thomsonii storage was 60%,in some serious occurrence,the rate of P.thomsonii with P.pentagona was 52.00%,and the serious damage rate was 21.56%.2.The Effects with the Damage of P.pentagona To the P.thomsonii During StorageP.pentagona damaged the P.thomsonii in storage to absorb nutrition for their own growth and reproduction;on the other hand,P.thomsonii epidermis injury due to absorbingnutrition by P.pentagona,susceptible to be bacterial infection and deterioration,so that the P.thomsonii inside became brown,and the nutrients changed.With the increase of the damage caused by P.pentagona,the crude protein and starch content decreased,and the crude fiber content increased,which seriously affected the taste and quality of the P.thomsonii.3.The Features of Occurrence and Damage of P.pentagona in the fieldIn 2014 in Gaoming,28 fields of P.thomsonii be surveyed,with the occurrence of P.pentagona damage rate was 46.42%.In the base of HECHAO,the serious place with the occurrence of P.pentagona and widespread occur,the insects rate as high as 42.7%.In the field,the P.pentagona is mainly distributed and damaged in Stems of P.thomsonii near the ground 30 ~ 50 cm.The Severely damaged plants,the whole plant of the stem covered with each insects state of P.pentagona and their secretion of white waxy material.So that the growth of pueraria lobata plant grows weak,leaves turn yellow and and fall off,seriously affected the growth and development of P.thomsonii.4.Investigation Results on the Source of P.pentagona in Storage Period and Growing PeriodAccording to the investigation of the potential host plants in the surrounding trees for the P.pentagona during the storage period,no suitable wintering sites were found.A survey of the potential host plants in the surrounding trees showed that the damage caused by the P.pentagona was serious in the field,and there was no parasitism in the surrounding host plants.Therefore,it is inferred that the P.pentagona in P.thomsonii storage is mainly due to the parasitic P.pentagona in the field and the nearby soil that they fall into.The source of P.pentagona in the field during the P.thomsonii growth period may be from two pathways: one way is the residual strains in the field and the soil for P.pentagona for winter;another way is to use the Stored P.thomsonii with P.pentagona as seedlings,the P.pentagona was brought to the field from the storage and continue to damage.5.The Effect of 5 Kinds Medicine for P.pentagona of P.thomsoniiThe results of the medicine test for P.pentagona in storage showed that the spray with6% Spinetoram suspension with 1,500 times dilution,22% sulfoxaflor suspending with4,500 times dilution,22.4% spirotetramat suspension with 4,500 times dilution and2.3% methylamino abamectin benzoate E.C.with 2,000 times dilution can well prevent and control the Female adult of P.pentagona,the highest effect reached 38.47%.The effect on the nymphs was significant,and reach ed99.28% ~ 100%.The results of the medicine test for P.pentagona in the field showed that with 6% spinetoram suspension with 1,500 times dilution,22% sulfoxaflor suspending with 4,500 times dilution,22.4% spirotetramat suspension with 4,500 times dilution,10% Imidacloprid wettable powders 2,000 times dilution and 2.3% methylamino abamectin benzoate E.C.with 2,000 times dilution spray on the female adult of P.pentagona have significant control effect,reached 100%;The best effect of this 5 kinds medicine test on the prevention and cure of P.pentagona was 2.3%methylamino abamectin benzoate E.C.with 2,000 times dilution,and the control effect was94.74%,followed by 22% sulfoxaflor suspending with 4,500 times dilution and 6%spinetoram suspension with 1,500 times dilution,control effect were 87.17% and 81.85%;While the poor control effect of 22.4% spirotetramat suspension with 4,500 times dilution and 10% imidacloprid wettable powders 2,000 times dilution was 67.21% and 63.75%.