摘 要：
棉蚜在棉田中为害程度的轻重是随着棉蚜发生的数量而变化的。为了进一步了解棉蚜发生规律,需要统计棉蚜在大田中每年消长的情况。我们前後在1936,1948,1949,1952及1953五年的棉花生长季节中曾在北京做了调查统计,并且在1953年在山西省解县和陕西省长安县也做了观察。现在把这些材料用曲线表示出来,同时在图表中加上当年的温度、相对湿度和雨量各线,以便研究它们对
译 名：
FIELD STUDIES ON THE POPULATION FLUCTUATIONS OF COTTON APHIDS
作 者：
CHU,H.F.;CHANC,G.S.Institute of Entomology,Academia Sinica
摘 要：
This paper deals with the studies on the population fluctuations of thecotton aphid, Aphis gossypii Glover, carried out in the experimental fields inPeking during 1936, 1948, 1949, 1952 and 1953. Aphid populations were re-corded daily during the cotton growing seasons of all these five years. The po-pulations of aphids for each year together with the relative humidity, temperatureand rainfall of the same year were plotted in graphs. Analysis and comparisonof. the graphs of all these five years resulted in the following conclusions:1. The population of cotton aphids in Peking tended increase gradually through- out these five years.2. Dry weather in May is usually followed by an outbreak of cotton aphids in June and July.3. The cotton aphid begins to make its appearance in cotton field in May and then multiplies rapidly in late May and beginning of June. Aphid population reaches its maximal point in June and lasts to the first half of July. The usual unfavorable climate in the middle of July cuts down the aphid population.4. Through careful study on the fluctuations in the aphid populations, it is re- vealed that the fluctuations in populations are closely related to temperature, relative humidity and rainfall. Daily maximum temperature and minimum temperature play little part in population fluctuations. Average temperature of 25℃, under certain conditions of humidity, acts as the critical temperature. Relative humidity has an important effect on the aphid population and it is shown that the aphid population decreases when the humidity reaches or over 75%. The combined effect of temperature and humidity on the aphid population is more evident. In general, cotton aphid population decreaseswhen humidity rises over 75% and the coefficient of temperature and hum-idity is over 3. On the other hand, population increases when the coefficientis less than 3 and temperature is below 25℃, or when temperature is above25℃ and coefficient is less than 2. The condition is quite interesting whentemperature is above 25℃, humidity is less than 75% and the coefficientis between 2 and 3. Within this range, when the coefficient is less than 2.5,aphid population decreases; on the other hand, when the coefficient is greaterthan 2.5 and less than 3, the population increases. It is found to have 92~+%of reliability when this is applied to our recorded data. It should be point-ed out that these correlations are obtained only from the data of our fieldobservations, and controlled laboratory experiments under constant temperaturesand humidities are necessary before final conclusions can be drawn. However,as is well known, heavy rainfall often cuts down the aphid population in thefield, but this is undoubtedly closely related with temperature and humidity.The correlation of temperature and humidity with cotton aphid populationmay be represented diagrammatically as in the following table:
