Although the wheat weevil is somewhat smaller than a grain kernel, it is one of the most important pests in grain stores: the small flightless weevil develops from an egg to an adult in a grain kernel. At optimum development temperatures of 25 °C to 29 °C, this takes around 34 days. After a few days, the new females lay 200 to 300 eggs and a new cycle begins.
Under current domestic storage conditions, two to three generations per year are possible. As a result of climate change, the period of optimal temperatures for the wheat weevils is being extended - more generations can form each year. Wintering is also easier for them, as the beetles can withstand temperatures of -10 °C for up to two weeks.
However, they must not get too hot: At temperatures of around 38 °C, thermal rigour sets in; temperatures of 39 °C to 40 °C lead to thermal death of the beetles.
