Study On The Types,hazard Characteristics And Control Methods Of Harmful Thrips In Shihezi Area

Shihezi area is an important area for the development of Xinjiang,and its primary economic industry is mainly cotton industry.Due to climate change,planting structure adjustment,farming system reform and other factors,the occurrence and harm of thrips in Shihezi cotton field are increasing year by year.It has changed from a secondary pest to one of the main pests in cotton field,which has a serious impact on cotton safety production.This study takes thrips in cotton field in Shihezi area as the experimental object,analyzes the species of harmful thrips in cotton field in Shihezi area,and studies the hazard characteristics,occurrence law and control methods of harmful thrips,so as to provide a theoretical basis for effective control of harmful thrips in cotton field.The results are as follows:1.Harmful thrips species in cotton field in Shihezi AreaFrom May to September 2021,the main regiments in Shihezi Area: 121 regiments,133 regiments,134 regiments,143 regiments,150 regiments and the cotton planting area of Shihezi University agricultural test field were investigated,and a total of 2321 thrips adults and 114 larvae were collected.The identified species are 7 species,belonging to 3 families and 4 genera respectively.Two species of Aeolothripidae:Aeolothrips fasciatus and Aeolothrips intermedius Bagnall;Four species of Thripidae: Frankliniella intronsa Trybom,Thrips tabaci Lindeman,scolothripstakahashii Priesner,Frankliniella occidentalis Peragnde;One species of Phlaeothripidae: Haplothrips tritici kurdjumoi.Among them,the harmful thrips in cotton fields are Thrips tabaci,Frankliniella occidentalis,Frankliniella intronsa.The total number of harmful thrips samples collected is: Frankliniella intronsa >Frankliniella occidentalis > Thrips tabaci.The survey found that the major occurrence period of thrips in each regiment was in July and August.The occurrence of harmful thrips in cotton field of 143 regiment was the largest,followed by 133 regiment,134 regiment,121 regiment and 150 regiment.2.Harmful characteristics and occurrence regularity of harmful thrips on cottonThe results showed that 5,10 and 20 Thrips tabaci could cause cotton to roll leaves.When 20 Thrips tabaci were connected in 1-leaf stage and 2-leaf stage,the leaf roll rate was the highest,which was 91.11%.When 20 Thrips tabaci were connected to cotton at cotyledon stage,the dead leaf rate and the rate of "headless cotton" were the highest,which were 46.67% and 35.56%.When 10 Thrips tabaci were connected to cotton,the phenomenon of "multi head cotton" appeared.When 20 Thrips tabaci were connected to cotton in 2-leaf stage,the incidence of "multi head cotton" was the highest,which was31.00%.Thrips were less harmful to cotton at the four leaf stage.The results showed that different numbers of Frankliniella intronsa could make cotton plants appear embroidered spots in different growth stages,and the number of insects was positively correlated with the spots.The rust rate of 1000 Frankliniella intronsa in the young stage of cotton was the highest,which was85.19%.When 500 Frankliniella intronsa were connected in bud stage and flowering stage,there was stiff crack boll when 200 insects were connected in young boll stage,and the rate of stiff crack Boll in 3cm boll stage was 0%.The results showed that in 2021,Thrips tabaci appeared on May 21,reached the peak on June 11,and moved out of the cotton field around June 25;Frankliniella occidentalis appeared on May 21 and peaked on July 23.Since September 3,Frankliniella occidentalis have not been found in the field;Frankliniella intronsa entered the cotton field on June 18 and reached the peak of the year on August 13.It is difficult to find Frankliniella intronsa in the cotton field after September 11.The results showed that the number of Frankliniella intronsa was the most in 9:00 and half flowering,reached the peak in 15:00,and the number of males was greater than that of females;From 15:00 to 18:00,the number of wilting flowers and half flowering showed an upward trend,and the number was the most in the half flowering at 21:00.3.Study on control methods of harmful thripsThe results showed that the treatment of cotton seeds with high,medium and low doses of thiamethoxam,imidacloprid and thiamethoxam could effectively prevent Thrips tabaci from harming cotton.The higher the concentration of the same agent,the better the control effect.Among them,the control effect of imidacloprid 8ml / kg treatment is the best,which can effectively prevent the phenomenon of "headless cotton"(100%)and "multi headed cotton"(87.24%).Arranging blue,yellow,light blue,white and heat dissipating white boards in the field has a certain control effect on thrips at flowering stage,and the number of insects attracted by each color board increases with the increase of time.Among them,the blue board has the best trapping effect on thrips in flowering stage,and 1325 thrips can be lured in 12 hours.The results showed that the control effect of ethyl spinosad suspension on Frankliniella intronsa was the best,and the control effect on the seventh day was 75.68%.