Third generation diamondback moth prevention and treatment
one. Pest Infestation At present, the third generation of diamondback moth has entered the moth, spawning and hatching period. Observing survey at the measuring point: The observation on this station was reported systematically. The third-generation diamondback moth detected egg masses from the end of April and entered the peak of spawning in mid-May. The cumulative number of 10 cabbages reached 1505, and the number of single plants was With an oviposition of 21.5 eggs, the number of larvae in the field began to increase gradually, with only 1.4-2.6 heads per plant in early May and 26.3 heads per larvae on May 16. According to the investigation at Huangdu, the adult moths of Plutella xylostella showed a moth peak at the end of May. During the peak period, the total number of moths was 791, accounting for 77.9% of the total number of moths in the near future. The single plant day in mid-May was observed. The egg volume is 7.5 grains and the egg peak is 12-16 days. Daejeon investigation: Currently, the parasitism rate of the diamondback moth is 100% in cabbage and cauliflower crops, and the number of eggs per plant is 30-40 in grain (head), and more in 70-90 grains (head), with an average of 50-. 80 (head) eggs accounted for 70-80%. The parasitic rate was 100% for green vegetables, 10-20 pieces (heads) for small eggs, 30-50 (heads) for many strains, 10-30 for head (average), and the ratio of eggs to eggs was 4 : 6, At present, field larvae are mainly larvae of 1 and 2 years old. two. Occurrence of damage trends This year, the diamondback moth is a medium-heavy year in the vegetables of our region, and the occurrence of damage will exceed that of the same period of last year. 2. Since mid-May, two to three spawning and hatching peaks have occurred in the middle and late May. three. Prevention opinion 1. Control period: 5/17-5/20, 5/25-5/27, 5/bottom-6/early. 2. Control range: cabbage, cauliflower, vegetables, hairy vegetables such as leaf-based. 3. Prevention of choice of pharmaceuticals: Rui Jin special, CPIC, Haizheng three orders, dishes hi, divisible, BT and so on. 4. Control requirements: pay attention to the quality of prevention and treatment; pay attention to the alternate use of pharmaceuticals; pay attention to the continuity of prevention and treatment. Each farmer can do a good job of prevention and control according to the actual pest situation in the field.