Regularity of occurrence and efficacy of insecticides in controlling Persimmon ceroplastes japonicus
Author of the article:LI Yan-Qiong1** ,LI Cong-Ying2, SONG Bo-Peng1 WANG Yuan-Li1 LI Jia1 LI Yi-Bin1
Author's Workplace：(1. Department of Horticulture, Agriculture Vocation-Technical College, Yuxi 653100, China;2. Agro-technical Popularization and Service Centre, Yiliang, Kunming City, Kunming 652100, China)
Key Words：Ceroplastes japonicus, persimmon, occurrence regularity, chemical control
Abstract： [Objectives] Ceroplastes japonicas Green is an important pest on a persimmon (Diospyros kaki L.f,), The regularity of occurrence of Persimmon ceroplastes was investigated inYuxi,Yunnan. [Methods] On the basis of local Persimmon ceroplastes japonicus phenological law system , to choose the effective drugs with randomized block design. [Results] This pest has one generation per year in this region and fertilized female adults overwinter on 1-2 year old branches of persimmon trees. Overwintering adults begin to develop in early February of the following year when the temperature is >6℃and lay eggs in early March. These eggs begin to hatch in late March and reach the hatching fastigium stage from early May to early June. Female insects gradually move from leaves to branches from early July to late autumn, and then enter the overwintering period. The control efficacies of 2.5% beta-cypermethrin EC and 40% methidathion EC five days after spraying on this pest were 93.7%, and 91.9% respectively, significantly higher than that of the other 5 insecticides. The control efficacies of 24% spirotetramat SL and a 20% abamectin-chlorpyrifos mixture ME 10 days after spraying were 96.2% and 92.9%, respectively, significantly higher than that of 2.5% beta-cypermethrin EC , 40% methidathion EC and 90% trichlorfont. The control efficacies of chlorpyrifos EC, 24% spirotetramat SL, 25% thiamethoxam WG and a 20% abamectin-chlorpyrifos mixture ME 20 days after spraying were 85.2%, 96.6%, 83.3% and 93.7% respectively, significantly higher than that of 2.5% beta-cypermethrin EC, 40% methidathion EC and 90% trichlorfon. [Conclusion] This research based on one generation about Persimmon ceroplastes Beta-cypermethrin EC and methidathion EC has better fast-acting property. Beta-cypermethrin EC and abamectin-chlorpyrifos mixture ME has better persistence.