| Arhopalus rusticus?Linnaeus?is an important stem borer of pine trees such as Pinus thunbergii Parl and P.densiflora in China,and has strong carrying capacity for B.mucronatus.At present,there are serious threats to forest resources in many areas of Shandong.In this study,the biological characteristics,the species and pathogenicity of the nematode and the chemical control of the larvae of A.rusticus in the coastal areas of Shandong province were systematically studied.The results were as follows:1.The adults of A.rusticus in Weihai area,Shandong,have 7 months of activity,and adults have been feathered from early May to the end of late November.There are two peak periods in one year,mid-June and early July,of which the first emergence peak period is more than second peak periods.In the Liugong Island forest area,the ratio between the A.rusticus and the Monochamus alternatus was 6.47:1,the number of A.rusticus between the forests accounted for obvious advantages.2.The internal reproductive system of A.rusticus female adults consists of 1 pairs of ovaries,1 contralateral fallopian tubes,1 middle oviduct,1 spermathecal gland,1 seminal vesicles and 1 pairs of attached glands.The unilateral ovary of the female brown stalks is composed of 7790 branches of ovary,and each egg tube is about 56 particles.3.In Liugong Island,the average number of nematodes carried in the single head A.rusticus in June was the largest number,with 1616.76 strips,then July?September?August and in August,with 1010.36 strips,300.00 strips,246.89 strips respectively.The average number of nematodes carrying nematodes in May was 218.39 strips,and the average number of nematode carrying nematodes in each month was not related to the sex of the beetle.In May,the incidence of nematodes was the highest,45.8%,followed by August?September,and July,the carrying rate was 43.9%,43.3%,32.1%,and the lowest rate was29%in June.4.The nematode carried by A.rusticus and the L?larvae of B.xylophilus is Similar in morphology,head round shield,mouth needle,esophagus ball is not obvious,insect body full of fat particles,tail with tail tip,the average body length=562.25?510.96687.57??m,average body width=20.09?16.4326.07??m,a=27.99.The results of PCR product gel electrophoresis of A.rusticus nematodes were 1000 bp,and the sequencing results were compared with the sequence of genes published on GenBank.The gene of this nematode was similar to that of Tylenchomorpha sp.SpondylisPT,and the degree of recognition was97%.The similarity between the 28s rDNA and the sequencing gene sequence was 39.55%.5.In this study,the virulence indoor of 5 insecticides to the larvae of A.rusticus was determined by immersion method and forest efficacy of five insecticides was done by using soaking the root of the tree in the forest.The results of toxicity test showed that 4%EC Cypermethrin had the best toxicity.Followed by 5%EC Avermectin?5%ME Emamectin Benzoate?2%CS Thiacloprid?10%CS Cyhalothrin,after 24h their LC500 values were3.400×10-5mg/L?4.500×10-5mg/L?1.140×10-4mg/L?4.720×10-4mg/L and 4.204×10-3mg/L.According to the test of indoor virulence,each agent LC955 was used to carry out the treatment of root irrigation in the forest,the results of field experiments showed that 5pesticides were highly active and could be used as the candidates for controling the larvae in stumps. |
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