The Ecological Studies on the Corn-linear Leaf-miner, Phytomyza nigra MEIGEN (I) : The Temperature Limit of Activity and the Diurnal Activity of the Corn-linear Leaf-miner

The investigations were carried out to know the temperature limit of activity, the locomotive velocity and the diurnal activity of the fly of the corn-linear leaf-miner, Phytomyza nigra MEIGEN. The results may be summarized as follows : 1. The range of temperature zone of normal activity was 31.8-10.3℃≒22℃ in female and 35.0-9.3℃≒26℃ in male. 2. Comparing to the other leaf-miners, the range of temperature zone of normal activity of this fly is closely allied to the corn-blotch leaf-miner and it narrower than of the chrysanthemum leaf-miner and the ranunculus leaf-miner but broader than of the rice leaf-miner and soy-bean root-miner. 3. The diurnal rhythm of activity of the fly is affected mainly by the diurnal change of temperature so that it depends upon the temperature reaction. The lower limit of activity of the fly is about 10℃ in the field. 4. In cloudy weather, the condition of rest gradually changes into of activity and the time beginning of activity is later than in fine weather. 5. The locomotive velocity, measured under gradually rising temperature, was calculated with ARRHENIUS' formula. The critical temperatures are at 20℃ and 29.03℃, and these temperatures somewhat agree with the temperatures at which the fly begins to fly and becomes nervous, i. e. 17.6℃ and 33.5℃ respectively. The temperature increments are as follows : Below 20℃‥‥‥‥‥μ=11372 20℃-29℃‥‥‥‥‥μ=14464 above 29℃‥‥‥‥‥μ=7146 6. The locomotive velocity under field conditions is very much intimately affected by the presence or absence of solar radiation.departmental bulletin pape