White grub threat temperatures in moderate climates

Our recent post on timing preventive applications for white grubs needs an important addition, for those of you in year-round moderate climates.That's because in areas such as coastal Southern California, there can be cool summers where threat temperatures may never reach the values of 70 or 71F that are listed for certain white grubs. Despite that, the adult beetles still lay eggs, and grubs still develop — although perhaps more slowly — and devour plant roots. For that reason, we…