Based on our degree-day model for Sparganothis fruitworm, flight initiation is expected at around 596 DD (see chart). As of May 30, Sparganothis has accumulated 607 DD (using March 1 as biofix) or 455 DD (using April 15 as biofix; a more realistic biofix based on the time when winter water was removed from most NJ beds). The later biofix indicates that flight activity will start very soon, i.e., within a week from now. Thus, growers are advised to place pheromone traps for monitoring this pest this coming week.
Degree-day model for Sparganothis fruitworm
