Abstract: Using the string bean, Phaseolus vulgaris, as the food plant, the effects of temperature and relative humidity (RH) on development, survivorship and food intake of the vegetable leafminer, Liriomyza sativae Blanchard, were studied. The results indicated a relationship of logistic curves between the developmental rate and the temperatures tested. The lower temperature threshold for development of the egg, larva, pupa and immature stage was estimated at 8.9℃, 10.1℃, 9.6℃ and 9.5℃ respectively, and the corresponding effective accumulated degree-day required for these stages were 57.7 DD, 53.9 DD, 151.9 DD and 264.2 DD. Effect of RH on development was little. When the temperature was >34℃ or <19℃, the survival rate of each stage decreased. The humidity mainly affected the survival of pupae. In RH<50%, the adult emergence rate declined obviously. Under conditions of higher temperature and lower humidity, pupae could not survive. The area of leave mined by the larvae at lower temperature was greater than at higher temperature, and the area was about 1.6 cm² at 25℃, while it was about 0.9 cm² at 28～34℃

Key words: Liriomyza sativae, temperature and humidity, development, survival, food intake