Thermal Unit Requirements for Determining Adult Emergence of the Western Cherry Fruit Fly (Diptera: Tephritidae) in the Willamette Valley of Oregon 1
- 1 June 1976
- journal article
- research article
- Published by Oxford University Press (OUP) in Environmental Entomology
- Vol. 5 (3) , 397-402
- https://doi.org/10.1093/ee/5.3.397
Abstract
A 3-yr (1973–75) study of the emergence of the western cherry fruit fly, Rhagoletis indifferens Curran, in the Willamette Valley, OR, indicated that fly emergence commences with the accumulation of a certain number of degree days or thermal units (TU). The 1st fly emerged at the accumulation of approximately 468 TU above a base of 5°C (air temperature). However, when the temperatures taken 5 and 10 cm below the soil surface were measured, the emergence occurred at the accumulation of 720 and 657 TU, respectively. The last fly was noticed at the accumulation of approximately 975, 1130, and 1056 TU, respectively, for the temperatures taken in air, 5 cm below and 10 cm below ground surface. Data further indicated that soil temperature 5 cm below ground was more reliable in predicting the fly emergence than the air temperature. A positive relationship was noticed between the accumulation of a certain number of TU and the emergence of various levels of fly population; i.e., 10%, 50%, 90% and 100%.This publication has 1 reference indexed in Scilit:
- Timing the Seasonal Cycles of Insects1Journal of Economic Entomology, 1944