Occurrence and control of main tea pests during summer tea

Due to the low temperature rain and snow weather in last winter and this spring, the base number of tea overwintering pests is low and the occurrence time is delayed, and the harm of spring tea is mild, but the weather in summer is more suitable for the occurrence and harm of diseases and insect pests. therefore, it is necessary to do a good job in the monitoring and control of diseases and insect pests.

The occurrence degree of whitefly was lighter than that of last year, but the number of insects in some tea gardens still exceeded the control target. According to the investigation of Songyang County Plant Protection Station, the peak of overwintering adults was on April 15, with an average population of 17.4 louvers, which was later and less than that of last year (April 5). It is predicted that the hatching peak of the first generation of whitefly this year will be around May 15. The appropriate period for control is from May 15 to 25. The suitable period of control in northern Zhejiang was postponed by 3-4 days. All localities should strengthen field investigation and grasp the appropriate period of control, low-capacity lateral spraying should be used, and spraying should be sprayed to the back of old and mature leaves. The medicament can choose 10% imidacloprid 20-30 g / mu or 40% chlorpyrifos 50 ml / mu, and the amount of spray liquid per mu should be more than 30 kg.

Tea inchworm

The number of insects in the first generation of tea inchworm is similar to that of last year. During the spring tea period, due to the lack of chemical control, there are more residual insects in the field. It is expected that the second generation of tea inchworm will be moderately heavy, and some tea gardens may be more serious. According to the field investigation of the first generation larvae in the tea garden of Longwu Town in Xihu District on April 16, mainly the second instar, it is predicted that the peak period of the second generation of tea inchworm 2nd instar larvae is about May 27. The tea area in northwest Zhejiang will be delayed by 2-3 days, and the tea area in southern Zhejiang may be 3-4 days earlier. All localities should start a field investigation at the end of May to determine the chemical control area, and tea gardens with more than 4500 insects per mu should be sprayed for control. The medicament can choose 2.5% deltamethrin 20-25ml / mu or 5% natural pyrethrum EC 80ml / mu. The preparation of tea inchworm nuclear polyhedrosis virus can be selected in organic tea garden.

Tea black moth

The second generation of tea black moth is the main harmful generation of the insect. According to the field age investigation of Hangzhou Tea Research Institute, it is predicted that the peak of the 2nd and 3rd instar of the second generation tea black moth is around June 12, the suitable period for field control is from June 13 to 18, and the tea garden with more than 3700 insects per mu should be fully sprayed. The medicament can choose 2.5% permethrin 25ml / mu or 80% dichlorvos 150ml / mu, 2.5% permethrin 15ml / mu + 80% dichlorvos 50ml / mu.

Occurs, the local insect quantity is more. According to the analysis of the average temperature in January and February and the rainfall in March and April this year, it is predicted that the initial period of the adult in the field this year will be around May 14, which is similar to that of last year, and the suitable period for field control is from May 28 to June 3. All localities should strengthen field investigation around May 25 to carry out pesticide control in tea gardens with more than 8000 insects per mu. The medicament can choose 98% shamindan 60g / mu or 2.5% bifenthrin 60ml / mu, and the application method is suitable for low-volume surface spraying.

Small green leafhopper with false eyes

It is expected that the first peak damage of false-eyed small green leafhopper will be moderately serious. According to the average temperature in March and April this year, the peak of the worm will be before May 20, which is an early onset year. All localities should start field investigation on May 15, and comprehensive spraying control should be carried out in tea gardens with more than 8 heads of loudworms, and the appropriate time for control should be applied when nymphs account for more than 80% of the total number of insects in the field. The medicament can choose 2.5% bifenthrin 25ml / mu or 10% imidacloprid 155g / mu or 98% carbendan 25g / mu. Beauveria bassiana preparation and matrine preparation can be used in organic tea garden.

(note: the safety intervals of the above pesticides are as follows: 6 days for bifenthrin, 6 days for dichlorvos, 5 days for deltamethrin, 10 days for imidacloprid, 10 days for chlorpyrifos, 7 days for shameidan, and tea gardens for export bases. the selection of pesticides should be determined according to the requirements of pesticide residues in the exporting country)