Population And Biological Characteristics Of Dioryctria In Korean Pine

Korean pine is one of the precious economic tree in Heilongjiang province,China,and the Dioryctria spp.are among the most damaging shoot/cone pest insects.It has the effect of causing the main shoots of the Korean pines to split into fat or break,and the cones are rot.Because of its similar morphological characteristics and living habits,it is difficult to distinguish;life is hidden and difficult to control.In order to clarify the species composition,population characteristics and bio-ecological learning of the spotted locust in the forest region of Heilongjiang Province,this study used light trapping and artificial collection in Mudanjiang Linkou Forestry Bureau to analyze the adult population dynamics and larval spatial distribution;observe its Adult reproductive behavior,as well as wintering insects and locations.The following were the results.(1)Analysis on the population dynamics of three Dioryctria of Pinus koraiensis plantationDioryctria rubella,D.abietella and D.sylvestrella were the three major moth species captured in the light traps at all three locations(Xibeileng,Hushui and Shuguang)tested.The highest trap catches occurred at Hushui with an average of 111.38 Dioryctria adults per day,followed by the traps at Xibeileng with an average of 79.625 Dioryctria adults per day,and the traps at Shuguang(the lowest)with an average of 69.63 Dioryctria adults per day.During the whole trapping period,D.rubella emerged from early June to late August,peaking between late June and mid-July,whereas D.abietella and D.sylvestrella both emerged from early June to late July,peaking at late June.Most of Dioryctria adults were likely captured during 21:00 and 22:00.(5)The sex ratios(?:?)of these captured Dioryctria adults varied through the season,starting from<1 to close to 1,and then reaching>1,but their overall sex ratios were close to 1:1.(2)Spatial distribution pattern and sampling technique of two kinds of Dioryctria larvaeUnderstanding the spatial distribution pattern and sampling technique of its larvae can provide a theoretical basis for the field investigation and control against these economically important pests.In current study,we analyzed the spatial distribution and sampling techniques of these two kinds of Dioryctria larvae,used by Iwao's distribution function and seven aggregation indexes.The results showed that the distribution of D.abietella and D.sylvestrella larvae in four directions were not significant difference.The damage rate of the cones and larvae density per plant in the High-bearing cone plots of D.abietella were significantly higher than those in lowe-bearing cone plots,but these two survey data of D.sylvestrella in two kinds of plots were not significant difference of.The seven aggregation indexes of the two Dioryctria species were shown as aggregate distribution,and the basic components of the distribution were individual colony.The individuals of the D.abietella larvae were mutually exclusive,and D.sylvestrella larvae were attracted to each other on Korean pine.?>2 indicates that the aggregation distribution is caused by the combination of the aggregation habits and environmental factors of the two species.Through the two distribution parameters ? and ? of Iwao's m*-m regression method,the optimal and sequential sampling for the two larvae under different bearing were calculated,for checked and use in prevention and treatment.(3)Feathering and reproduction of D.abietella and D.sylvestrellaThe female of D.abietella feathering is concentrated at 08:00?10:00,and male feathering is concentrated at 08:00?12:00.The female of D.sylvestrella feathering is concentrated at 02:00?08:00,and the male feathering is concentrated at 04:00?8:00.The female of the two Dioryctria can calling at 1-5 days old.For D.abietella,the peak of calling at 20:00?00:00,and the second peak is at 00:40?08:00.For D.sylvestrella,the peak of calling at 20:00?00:00,and the second peak at 00:40?08:00.For D.abietella,the calling peak period of forest edge was 1.5 hours earlier than the indoors.For D.sylvestrella,the calling peak period of forest edge was 1.hours earlier than the indoors.Older virgin female will be calling in advance than the newly emerged female.In the presence of male competitor information,male will prolong the duration of mating,but there is no significant change in the amount of eggs.(4)Supplementation of the biological characteristics of D.abietellaD.abietella are wintering with the young larvae,the older larvae and the pupations.Among them,the form of wintering is pupations,accounting for 57.21%.The wintering place is cone,litter layer and soil,and the mainly piace is cones,accounting for 75.82%.Among them,the survival rate in winter is the highest in the pine cones,which is 46.5%.In summary,through the study of population dynamics,wintering patterns and spatial distribution of larvae of Dioryctria,the composition of the Dioryctria species was determined,and the characteristics of adult and larvae were mastered,which provided a basis for effective comprehensive control of Dioryctria.Through the observation and research on the reproductive behaviors such as calling and mating of the Dioryctria,the peak of calling and mating behavior characteristics were determined,which laid the foundation for the future sex pheromone extraction and forest control.