Study On The Occurrence Regularity In Shandong And Jiangsu Province And Ovarian Development Of Small Brown Planthopper Laodelphax Striatellus (Fallen)

Laodelphax striatellus (Fallen)(SBPH), belonging to the Hemiptera, Delphacidae, can spread Rice stripe virus (RSV), Rice black streaked dwarf virus (RBSDV) and Maize rough dwarf virus(MRDV) and so on, the damage caused by the virus it transmitted is far greater than direct sucking damage. It can overwinter safely in temperate zones, in China, it distributes across the country, and manily in Yangtze River Basin and North China. Recent years, Laodelphax striatellus (Fallen) frequently outbreaks at home and abroad, it suddenly outbreaks in Jiangsu, Shandong province and West coast of South Korea and Japan at the same period in Spring, it is consistent with some of the characteristics of the migratory insects. Therefore, it is necessary to study its outbreaks regular pattern, clear its migration characteristics, and strengthen monitoring and early warning and controlling from the source, and to do it is crucial for reducing the hazards of L. striatellus on food crops. The progress of ovarian development is one of the indicators to determine the nature of migratory insects, however, in actual production, it is likely to occur that because of personal understanding deviation to ovarian grading standards, causing misjudgment. So, it is necessary to provide the grading criterion and pictures of the ovarian anatomy of L. striatellus. In this study, the main contents and results are as follows:1. Population dynamics and migration characteristics of the small brown planthopper in spring in Jining, Shandong province, in2009and2010The population dynamics and generation properties of the small brown planthopper (SBPH) in light traps, wheat and rice seedling field in Jining, southwest Shandong Province, China were studied through hourly light-trap catches, systematic field survey and dissection of macropterous female ovarian. By using Grads and ArcGIS, the weather backgrounds during the immigration and the emigration peak were analyzed. The migration pathways of SBPH were simulated in the above two periods by using HYSPLIT, a trajectory analysis software for the simulation of migratory trajectory. The main results were shown as following:(1). There are immigration into the seedling field in Jining, and the small brown planthopper in the wheat field can do long-distance migratory by proper airflow; through hourly light-trap catches in night,we found that there were a large number of migratory L. striatellus, flapping lights at midnight or after midnight.(2). There were a few immigration and emigration peak of SBPH in spring in2009,2010in Jining.(3). The trajectory backward analysis showed that the source regions of immigration population of SBPH were mainly from Shuyang and Sihong County, in Suqian, northern Jiangsu, and Danyang, southern Jiangsu, while the trajectory forward analysis showed that the SBPH might emigrate to Mongolian Autonomous County of Harqin Left Wing, Zhaoyang, western Liaoning, and the junction of Dalian and Dandong, and Gangwon-do, North Korea on the15th of June,2010. Heavy precipitation and anticyclone could be the main factor affecting the centralization landing during immigration or emigration, the landing areas of SBPH were on the edge of the main rainfall zones.2. The small brown planthopper dynamic analysis over the years in Danyang City, and Ganyu County, in Jiangsu ProvinceThis study analyzed the light trap catches and field survey data of SBPH from2000to2011in Danyang and Ganyu, Combining with meteorological data, we used SAS to do correlation analysis between the average monthly temperature, precipitation and annual quantity of SBPH; By using Grads and ArcGIS, the weather backgrounds during the emmigration peak in2007were analyzed. The migration pathways of SBPH were simulated in the above period by using HYSPLIT. The main results were shown as following:(1). Both in Danyang and Ganyu, the most serious year of outbreak of SBPH is2007, it outbroke in light traps in Danyang and Ganyu at the same period in Spring, the harm caused by the first generation of SBPH in light traps is most Serious, and in recent years, the trend of it occurred is in advance, and the hazard caused by4th,5th generation has aggravated.(2). The correlation between the average monthly temperature when L. striatellus overwinters and the first generation adults occurred and the annual quantity of SBPH is the largest and it’s a positive correlation. The average monthly precipitation when the first generation adults emerged follows, and it is a negative correlation between them.(3). The first generation of adults of SBPH would emigrate to the west coast of South Korea and Japan from Danyang, in2007. 3. Eclosion rhythm indoor and ovarian grading standards of SBPHSBPH were raised with seedlings of there-leaf stage under temperature26℃, relative humidity of75%and photoperiod14L:10D conditions. Through observing the eclosion rhythm and dissecting the female SBPH by six hours, and photographing the ovarian using inverted microscope, the morphological changing processes and grading criteria of ovarian development of SBPH had been vividly and detailedly described.The results are as follows:(1) Eclosion time of SBPH raised with seedlings of there-leaf stage was concentrated at08:00-09:00in the daytime;(2) Ovarian grading boundaries of SBPH are:we define whether tubal plug is in lateral oviduct or not as grading standards of level Ⅰ and Ⅱ, When the tubal plug has not yet appeared in lateral oviduct, but the white vitellus deposition has arised in the ooecium of ovarin tubule, we classified it as grade Ⅱ; We regard the presence or absence of mature eggs in the ooecium as the boundary of grade Ⅱ and grade Ⅲ; We consider the number of mature eggs, the level arranged in neat and the presence or absence of empty section in the ovarin tubule as grading standards of grade Ⅲ and Ⅳ; We consider whether the constriction of ovarian tubule and disappearance of mature eggs turns up or not as grading standards of grade IV and V.We also provide the schematic diagram of the ovarian development.