Study On The Investigation On Occurrence And Damage Of Sichuan Pepper Scale Insects And The Green Prevention Control Technology Of Pseudaulacaspis Pentagona In Luding County

The Sichuan pepper industry is an important poverty alleviation industry in Luding County,and is the main economic source of farmers and herdsmen in Tibetan areas of Luding County.Due to the lack of scientific management,scale insects seriously damage the Sichuan pepper and the severe occurrence of this pest is not conducive to the healthy development of Sichuan pepper industry of Luding County.In this paper,the species,distribution,occurrence and damage degree of scale insect as well as environmental factors and cultivation management of Sichuan pepper were systematically investigated and studied in the growing areas of Sichuan pepper in townships and towns of Luding County.The relationship between different factors(the species and tree ages of Sichuan pepper,altitude,slope,intercropping and cultivation management of Sichuan pepper)and occurrence and damage of scale insects were analyzed.In order to develop scientific and reasonable scale insect control plan and guide the production of Sichuan pepper in Luding County,the green control experiments of Pseudaulacaspis pentagona were carried out by using insecticides with high efficiency and low toxicity,scouring with high-pressure water and introducing ladybugs.The findings are summarized as follows:1.There are four main species of scale insects that damage Sichuan pepper in Luding County,including P.pentagona,Drosicha corpulenta,Phenacoccus aceris and Chloropulvinaria floccifera,with incidence rates of 56%,24%,15%,and 14%,respectively.Pseudaulacaspis pentagona occurred in all Sichuan pepper planting towns and the occurrence was the most severe,while C.floccifera only occurred in Lengqi and Dewei Town.Sichuan pepper scale insect infestation began in mid-March,reached its peak in June,and continued infestation from July to August until the completion of Sichuan pepper harvest.The scale insects initially appeared as dots on Sichuan pepper.After a few weeks,the number of scale insect nymphs increased,and then the patchy distribution was formed.The occurrence of scale insects was serious in 2021,with the local plots where scale insects occurred accounting for 60.0% of the surveyed plots.2.Different factors,such as variety,tree ages,environment and management of Sichuan pepper,had influence on the occurrence of scale insects.Scale insect species decreased as altitude increases.All four kinds of scale insects occurred at 1700 m,three at2000 m,and only P.pentagona occurred at 2300 m,with P.pentagona having moderate or severe damage at all altitudes.However,slope change had no obvious effect on Sichuan pepper scale insects.Different varieties,tree ages,different intercropping and management methods had certain effects on the occurrence regularity and damage degree of scale insects.P.pentagona preferred Dahongpao and Luzheng pepper as hosts.Trees over 3years old began to be affected by a variety of scale insects and showed an increasing trend year by year.The damage degree of P.pentagona to Sichuan pepper was serious when and Sichuan pepper intercropped with walnut.When Sichuan pepper intercropped with plum,the damage degree of P.pentagona on prickly ash was medium.when Sichuan pepper intercropped with cherry,the damage degree of P.pentagona on prickly ash was relatively light.The ecological environment around Sichuan pepper should be fully combined to prevent and control Sichuan pepper scale insects better.According to the local ecological environmental conditions,resistant varieties with strong tolerance should be selected,and companion planting of different cultivars and appropriate rotation should be considered.Timely and effective control of Sichuan pepper scale insects is also needed.3.The results of laboratory efficacy test showed that 22.4% spirotetramat suspension(4500 times dilution),4% abyl.Acetamidine water emulsion(1500 times dilution),10%imidacloprid wettable powder(1500 times dilution)and 25% thiazinone wettable powder(1000 times dilution)had significant effect on both P.pentagona adult and nymphs.After21 days of application,the control effects were 93.3%,80.7%,74.2%,67.0%,respectively.After 21 days of application,the filed control effect of 22.4% spirotetramat suspension(4500 times solution)against P.pentagona was the best with the control effect of 95.6%followed by 10% imidacloprid wettable powder(1500 times dilution)and 4% avyl.Acetamidine water emulsion(1500 times dilution)with the control effect of 77% and 78%,respectively.The control effect of 25% thiazinone wettable powder(1000 times dilution)was relatively poor with the control effect of 62.2% after 21 days of application.4.The results showed that the control effect of portable high-pressure water gun on P.pentagona was significantly better than that of traditional manual brushing and the quick effect was good.After 1 day of treatment,the control effect reached 68.4%.Coccinella septempunctata and Chilocorus kuwanae had good control effects on Sichuan pepper.And no pollution to the environment,After 10 days of introducing these two ladybirds during the blooming period of P.pentagona,the corrected control effects reached 74.8% and80.9%,respectively,and they are safe to crops.