Degree days modelling is a methodology to assess pest insect development stage based on heat accumulation. Insects are exothermic or cold-blooded, therefore their body temperature and growth are fundamentally affected by temperature in their environment. They require a certain amount of heat accumulation to reach certain developmental stages, such as egg hatching, pupating or adult flight. For example Codling moth requires around 250 Degree Days (DD) to begin egg hatch and around 350-600 DD to reach peak flight of the first generation.
In order to use the degree days model within Trapview WEB application a few parameters should be set by the user initially. The first parameter is the date of the start of monitoring season or the date of when the first insects were captured/observed in the trap (so called biofix). The next parameters are Lower development threshold (LDT) and Upper development threshold (UDT). Below the LDT and above UDT development of insects is rapidly slowed or does not occur. The threshold values depend on particular insect species and also on monitoring location. Default values are provided in the Trapview application based on accessible information available. However, the thresholds can be modified based on actual pest development and saved to be used for the following seasons.
Degree days modelling in Trapview is also a convenient way to lower the cost of monitoring different pests simultaneously. Trapview WEB application allows users to set degree days models for up to three different pests per single trap. The feature can be accessed by following the link Select additional monitored pest in the Degree days tab (please see the picture above).