Studies On The Genus Dioryctria Spp.and The Biology Of Four Species On The Korean Pine

Korean pine Pinus koraiensis Sieb et Zucc is one of the native important trees, its distribution is limited to the Northeast China, North Korea and the Far East region of Russia. It is the s excellent species of wood, the vintage materials and its seeds possess of very high economic value and role of health care. In recent years, because of the shortage of the seeds and timber, the seed prices of the pine continue to rise around the world. So, the eastern mountain area of Jilin Province have already strengthened currently the management of pine forests and vigorously cultivated new plantations. With the changes of forest stand conditions and the composition of forest stands, the Korean pine pests increasingly serious harm also, the Korean pine insect pests in some regions damaged as high as 80%, or total destruction of the pine growth and seed yield. Among the pests of the pine branches and cones, the genus Doryctria is the one of the main pests, is also the main damage groups in the eastern mountain of Jilin Province.Doryctria spp. Zeller (Pyralidae ,Lepidoptera), some species are serious damage in which formed the canal of the shoots and cone, their larvae damage the shoot and cone of the pine,. It has reported fifth species of the genus Doryctria in China, and has recorded seven species in Jilin province. But the author researches the Doryctria spp. in Jilin province and found some homonym species in the seven species. This article confirmed five species in Jilin province:1. Dioryctria abietella (Densis et Schiffermüller),2. D. sylycstrella (Ratzeburg),3. D. pryeri Regonot,4.D. rubella Hampsona,5. D. schuetzeella FuchsThe fomer four species can harm Korean pine.The research specimens were from two ways: the author collected the larvae and breeded until emergence in Jilin ,2006; and another way was every 5-10 days to observe in sample plots, record on the activities, development stages ,morphological changes of the pests in Huangnihe, Dunhua city. the sample plots have 3 stands: 10yr stand, 15yr stand and 30 stand, each stand was about three hectares. Each plot survey randomly 30 trees, every 10 days per 1 time, from May to September.The morphological characteristics, life histories and habits have known. The results show that from the larvae stage of Doryctria like bore and damage shoot, especially serious damage 2-year cone.D. abietella occurred a generation per year, 3-4instar larvae winter over inside the cocoon in 2yr cone and the shoot,. In late April the following year, when the temperature rises, gradually regained consciousness and began activities. In late May the larvae mature and begin to pupate. Several generations of this pest very disordered, in mid-June to late July they can be seen the different ages of the larvae, the pupae and the adult and the egg.D. sylycstrella occurred a generation per year. 2-3 instar larvae winter in the tumor pack of pine shoot. The following year, beginning in late April of activities. In late May larvae continued aging walls started to pupate. In mid-August the adult emergence, mating and nesting. In late June the new larvae hatching. In mid-September larvae in the next round of troubles-tumor pack, thin silk cocoon for the winter.D. pryeri complete a generation per year. Pine shoot in the trunk or subcutaneous silking networking winter. The following year early in May and Breaking Away from the larvae feeding, the majority of mid-May larvae have moved to the beginning of the shoot-inflorescence on hazards. Beginning in mid-June to pupate. More mature larvae bore in the aftermath of the ground shoot tip above 3 cm pupation, a handful of litter layer pupate. At the end of June early July emerging adults, in early July for the emergence period, and after mating spawning. Seven new mid - to late hatched larvae, endangering the new shoots 10 in late winterD. rubella complete a generation per year. From mid to late of September the larvae begin to winter in the shoot and cone, some larvae in the branches also. The early in May of following year begin to damage. In the end of June or early July the larvae pupate and then emerged in mid-July.