【摘要】 根据东北地区的粘虫极大可能不在本地越冬而是每年春季随南、西南风大量迁飞的假设,利用气象资料分析了东北早春粘虫成虫的发生与风向风速的关系。无论由始现期或突增期来看,与地面上或高空850 mb的南、西南风均有较高的符合率;在粘虫出现时期的南、西南风多为每秒5—6米到每秒9—10米的大风。由分析中也看出了,东北地区在许多地点经常同时发生粘虫的出现与突增,而该时期在天气图上东北全区或大部分地区均有南、西南风,由以上的风向风速,估计由假定的南方粘虫发生地只需一天左右的时间即可到达东北。由上述结果讨论了粘虫春季迁飞的可能性,东北地区粘虫的虫源问题以及粘虫成虫是否还具有夏秋季回迁的可能。更多还原

【Abstract】 In a meeting held at Harbin 1959, discussing the possible over-winter sites of theOriental armyworm, Leucania separata Walker, in the Northeast, a hypothesis was pro-posed (Chang, 1959) that this insect most probably did not over-winter in the Northeast,but the outbreak every spring was due to mass migration of the adult moths along withthe south or southwest trade winds. The hypothesis was based upon the followingfacts: 1. The appearance of the armyworm moths in early spring is in the form of suc-cessive and intermittent peaks, and the dates of these peaks coincide with the simultane-ous appearance of the south or southwest winds (usually the wind velocity is above10m/sec.). 2. Of nine different localities from south to north in the Northeast (Dairen, Shen-yang, Chingchow, Kungchuling, Harbin, etc.) which differ greatly in latitude, hence intheir average daily temperature in April to June, the dates of the peak of appearance ofthe armyworm moths differ only by 1--3 days, suggesting that the moths occurring inthe different localities were from the same source and were carried by the same windfrom south to north. 3. That the armyworm moths have the habit of flying in large groups, and flyingto very high altitudes, is well known. 4. There were reports that large numbers of dead moths, identified to be Leucaniaseparata, found on the sea near Changshan Island and Wengten Hsien, suggesting pos-sible miscarrying of the wind. 5. For about 10 years of extensive search of overwinter sites in the Northeast,covering about many thousands acres of different types of cultivated lands, steppe,islands, hills, forests etc., not a single insect had been found. 6. Field breeding experiments in fall and winter with different degrees of winterprotection, had failed to carry this insect over the winter; and the tracing of the army- worm moths in the fall had also failed to yield any positive clue. 7. The cold tolerance of the Oriental armyworm, whether egg, larva, pupa oradult, had been found to be very low. Considering the temperature conditions of thesevere winter in the Northeast, the overwintering of this insect in situ was rather un-likely. 8. The outbreak of the armyworm in a small locality is usually very sporadic (i.e.it may occur in large numbers in one year and almost be entirely absent in another), butthe general distribution of this insect in the entire Northeast is rather well defined. Thissuggested that the outbreak of the armyworm in a small locality is determined by whe-ther the wind has carried the moths to that place; but as there is certain regularityin the direction and route of the trade wind, the overall distribution in the whole areais rather constant. 9. It is well known that many noctuid moths are regular immigrants, among themis the common armyworm moth, Pseudaletia unipuncta, the closely related species of theOriental armyworm; thus it is very likely that Leucania separata may also be a regularimmigrant. Based upon the above hypothesis, a series of work was conducted to study the migra-tion of the Oriental armyworm moths. The present paper is the first report analyzingthe relationship between the appearance of the armyworm moths in the early spring andthe prevailing winds. Further work is now in progress, studying the effects of othermeteorological factors on the migration of the moths, the capture of the moths on theirway over the Gulf of Chili. The daily capture record of the Oriental armyworm moths of six localities in theNortheast (Dairen, Hsiun-yo, Chingchow, Shenyang, Kungchuling and Harbin) in the years1956--1959 were analyzed together with their local meteorological records and the me-teorological map of the Eastern Asia. The following results can be seen: 1. The dates of the first appearance of the moths coincided in most cases with thesimultaneous appearance of south or southwest winds. The percentage of coincidence ofthe six localities on the average was over 70%, while the percentage of coincidencewith other wind directions was very low. 2. The dates of sudden increase in numbers of the moths also coinci更多还原