Research On Green Control Of Major Oil-tea Pests In Guizho

Camellia oleifera belongs to the family Theaceae,and is one of the four unique woody oil crops in China.It is a high-end edible oil comparable to olive oil,accounting for more than 80% of domestic high-end vegetable oils.Together with oil palm,olive,and coconut,it is known as the world’s four largest woody edible oil plants.Insect pest is one of the main reasons that affect the quality and yield of C.oleifera.The invasion of insect pests seriously restricts the healthy development of the C.oleifera industry in Guizhou.Currently,the prevention and control of C.oleifera pests is mainly based on a single chemical control method.Chemical control has drawbacks such as easy to damage the ecology,causing pollution to the environment,and causing drug resistance to pests.Moreover,as an edible oil crop,the application of chemical pesticides can pose a certain risk of poisoning,In recent years,due to the "3R" problem of chemical control and the increasing attention paid to food safety and ecological environment safety."Green prevention and control can greatly reduce the" 3R "problem of chemical control,and effectively avoid problems such as poor effects of single measures such as physical control and biological control.".Therefore,carrying out green control research on C.oleifera pests has become an important link in the C.oleifera industry.In order to clarify the main pests and their occurrence dynamics in Guizhou camellia,and develop corresponding green prevention and control methods,this study investigated the main camellia producing areas in Guizhou,screened efficient and low toxicity prevention and control agents,combined with biological and physical methods for prevention and control.Through pesticide residues and yield testing,the effects of various prevention and control measures were tested,and the following research results were obtained.The research results are of great significance for increasing the production and income of camellia,and improving the yield and quality of camellia,It also provides effective technological support for the high-quality development of the C.oleifera industry.(1)Investigation on Main Pest Species of C.oleifera in GuizhouThe results of interforest system investigation show that there are 38 species of major pests of C.oleifera in 7 orders,26 families,and 38 species in Guizhou.Among them,Hemiptera had the largest number of species,with a total of 16 species,accounting for 42.2% of the total;10 species of Coleoptera,accounting for 26.3% of the total;There are 7 species of Lepidoptera,accounting for 18.4%,3 species of Orthoptera,accounting for 7.9%,and 1 species each of Isoptera and Tasseoptera,accounting for 2.6%.From the perspective of harmful parts,the leaf-eating pests were the most,with 22 species,13 branch pests,4 fruit pests and 4 root pests.Among them,serious insect pests mainly occur;Euproctis pseudoconspersa,Parametriotes theae,Toxoptera aurantii,Dichocrocis punctiferalis,Curculio chinensis,Basilepta fulvipes,Lawana immita,Ricania speculum,Eurasia magnanima,Homona coffearia,Cosmoscarta heros,and others took the second place.The adult of C.chinensis was unearthed around late March,and the peak period of adult occurrence was from June to July,until around late September when there was no adult activity in the forest.The number of insect populations in the old forest is slightly higher than that in the young forest.The peak period of insect population is roughly from June to July,and the highest number of insect populations in the old forest is around mid July.The overwintering larvae of the P.theae gradually take fresh tender branches and leaves of edible oil tea from around early March.The larvae begin to worm into the tender branches around late April,and pupation occurs from mid May to late June.From late June to early July,they emerge and lay eggs.Most of the larvae begin to overwinter around December.The adult of Anomala copulenta is common from March to September,with an increasing trend in the number of traps.The peak period of adult infestation is from June to late July,and the maximum number of traps reached 36 on July 14 th.From mid July onwards,the number of traps gradually decreased until late September,when the number approached zero.T.aurantii appear when new branches of Camellia oleifera begin to sprout in late March.Starting from early April,the number of T.aurantii increases explosively until the peak of insect population is reached in mid to late May.In June,as the branches and leaves of C.oleifera gradually age and the number of natural enemies increases due to rising temperatures,the number of T.aurantii begins to decline.Until mid July,tea aphids are not observed on designated plants in the forest.(2)Screening of Three Pest Control Agents for C.oleiferaThe indoor toxicity of the six pesticides to C.chinensis is from strong to weak,respectively;Metarhiziumanisopliae > Beauveriabassiana > Cyfluthrin > Imidacloprid>Nicotine Matrine > Imidacloprid thiazidone.After 7 days,the field control effects were from strong to weak for cypermethrin,imidacloprid,nicotine,matrine,pyrazidimefon,and Beauveria bassiana,Metarhizium anisopliae,respectively.The prevention and control effects were 83%,77.34%,71.67%,66.01%,60.33%,54.67%.The indoor toxicity test results of the five insecticides to P.theae larvae were as follows: Imidacloprid < matrine < bacillus thuringiensis < avermectin <cypermethrin.In the field,the overall control effect of cypermethrin(73.51%)> matrine(69.35%)> avermectin(67.1%)>Bacillus thuringiensis(65.24%)>imidacloprid(53.13%).Phoxim and fenitrile thiacloprid have a high mortality rate against white grubs,and their field control effects are as follows: Among them,the relative control efficacy of octathion was 80.41%,chlorfenitrin clothianidin 69.55%,imidacloprid 17.39%,Metarhizobium 19.56%,and Metamorphosis albicans 8.69%.(3)Research on Biological Control of T.aurantiiDuring the process of biological control research on T.aurantii,it was found that the average daily feed intake of each adult of the heterochromatic ladybird Harmonia axyridis to the tea aphid T.aurantii was as high as 127,the daily feed intake of the first instar larvae of the black belt aphid fly Episyrphus baltetus was 60,the daily feed intake of the adult of the aphid eating gall midge Aphidolets abietis was 43,and the daily feed intake of the first instar larvae was 29.The daily feed intake of the first instar larvae of the heterochromatic ladybird H.axyridis was 34.Field experiment results: After 7 days of single placement,the control effect of A.abietis was 33.86%,and after 14 days,it was 57.47%.After 7 days of single placement,the control effect of H.axyridis egg card was 22.04%,and after 14 days,it was 66.92%.After 7 days of mixed placement,the control effect was 38.62%,and after 14 days,it was 75.43%.(4)Study on the Control of Main Pests in C.oleifera by Physical Control MeasuresThe insecticidal lamp has attracted a total of 42 species of insects from 30 families,8 orders,among which Lepidoptera accounts for the largest number,with 20 species from 12 families,followed by Coleoptera,with 13 species from 8 families,4 species from 4 families of Orthoptera,and 1 family from 1 species from each of Hemiptera,Neuroptera,Hymenoptera,Euptera,Mantis,and Dragonfly.A total of 19 species of insects belonging to 3 orders,12 families,were attracted by sugar and vinegar solution,of which Lepidoptera accounted for the largest number,with 14 species belonging to10 families,4 species belonging to noctuidae,and 1 species belonging to the other 9families.Coleoptera pests mainly belonged to the family Trollidae,with 5 species belonging to 1 family,and 1 species belonging to 1 family,Hymenoptera.The yellow and blue plates have attracted a total of 17 species of insects from 5 orders,12 families,and the number of Hemiptera pests is the largest,with a total of 10 species from 5families,3 species from the Cicadaceae family,4 species from the Brachyopteraceae family,1 species from each of the remaining 3 families,2 species from each of the Diptera,Lepidoptera,and Thysanoptera families,and 1 species from each of the Coleoptera families.(5)Effects of comprehensive prevention and control measures on the yield of C.oleifera In this experiment,the yield per plant of treatment 6 was 5.77 ± 0.75 kg,which was the highest among all treatment groups.The yield of control group was the lowest,2.19 ± 0.75 kg.There are certain differences in various fruit indicators among all treatment groups,and there is no phenomenon that one or more treatment groups are in the forefront of various fruit indicators.However,based on all indicators,the indicators of the control group are slightly lower than those of each treatment group.None of the chemical agents and pesticide residues used were detected.