| Cinnamomum camphora is one of the representative tree species of lauraceae,which is also one of typical trees in Hefei.With beautiful appearance and luxuriant foliage,camphor tree is well-received by local citizens.The tree is not only planted as border tree,but also is widely used in green landscapes such as street,park,highway,railway and so on.However,in these few years,insect injury is widespread and out of control,which causes the loss of sapling and the decrease of greening level in local city.As far as the local area is concerned,there are several kinds of insect injuries that harm the growth of cinnamomum camphora seriously,destroy the shape and appearance of these trees,which have a terrible effect on the function of urban beautification.There are eight administrative regions in Hefei,then the author choose 2-3 standard sample areas from each regions,combine the light trap and man-made investigation,and fix regular survey monthly.The content is focused on the main kinds of insect injuries,biological characteristics,the pattern of injury occurrence,the symptom of injury,and the degree of injury.According to the investigation,there are twenty-seven kinds of insect injuries in local camphor tree,including six kinds of main insect injuries:mansoniella cinnamomi,silver grain leaf moth,orthaga achatina,Aleurocanthus spiniferus,trioza camphorae,mesoneura rufonota.The degree of insect injuries:Orthage achatine(21%)>Stephanitis macaona(20%)>trioza camphorae(19%)>Acrocercopsordinatalla(14%)>aleurocanthus spiniferus(9%)>mesoneura rufonota(9%).Orthage achatine borns two generations each year in Hefei.It exists generation overlapping.June and July is the peak period of larva injury,because the larva spins and builds a cocoon which looks like a bird's nest in distance.The experimental results showed that 30%EC had the best control effect.Trioza camphorae borns two to three generations each year in Hefei.The end of May and the beginning of June is the peak period of insect injury.The infested leaves exist black uneven holes.Planting trees close to the downtown area is moderately hazardous.Although the disease in the suburbs exists,it is not very serious.Acrocercops ordinatalla borns nine to ten generations each year in Hefei.It exists generation overlapping.The peak insect injuries occurs in early June and late August.Infested tiny buds and tender leaves look like zigzag tunnels.Stephanitis macaona borns four generations each year in Hefei.The members of these pests would reach the climax after late July.Infested leaves appear brown spots apparently on both sides.The experimental results found that 5%EC had the best control effect.The effectiveness of more than 90%in 14 days.Aleurocanthus spiniferus borns four to five generations each year in Hefei,it exists generation overlapping.The climax injury happens in the late May,the middle of July,the late August and September.Infested leaves are dark black.Mesoneura rufonota borns two generations each year in Hefei.It exists generation overlapping.The injury peak period is the sprouting stage of camphor tree in spring and summer.The larva eats the leaves which causes the appearance of holes.According to the investigation,we can have a general knowledge of the pest life history and the occurring pattern of main insect injury in Hefei,which can offer basic data support to the landscaping of government as well as the pest control department.As a result,we could manage the insect injury effectively as far as possible and optimize living environment for local citizens,so that we are able to lay a solid foundation for green city development in near future!... |
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