The Nantucket Pine Tip Moth (Rhyacionia frustrana) is an important pest on pines in some areas. Overwintered Nantucket Pine Tip Moth pupae typically emerge in late winter/ early spring and the first adults may be seen soon after. There can be up to 4-5 generations in a year, depending on the location and weather. Insecticide treatments targeting 1st generation larvae are typically the best way to control Nantucket Pine Tip Moth populations for the entire growing season. The Nantucket Pine Tip Moth Growing Degree Day Model, developed by researchers, and available on the Pest Prophet app, is a tool growers can use to predict egg hatch based on adult trap catches and field-specific temperature data.

Initiating the Biofix

To properly use the model, the biofix must first be set. This is the date that will serve as the starting point for growing degree day accumulation. For Nantucket Pine Tip Moths, this biofix is the first date of consistent, sustained adult moth catches using pheromone traps. Traps should be placed in early spring, or late winter, and checked on a regular basis. Once adult moths have been trapped for a few weeks in a row, the date of the first catch should be used as the biofix.

Growing Degree Day Accumulation and Treatment

After the biofix is set, growing degree day accumulation can begin, using a lower threshold of 5.5C and an upper threshold of 37.35C. This can be done using daily high and low temperatures, or using hourly temperature data using the Pest Prophet app. The optimum timing for a single insecticide treatment on larvae will be approximately 1262 GDD (C) after the adult moth catch.

Source:

Malinoski, M. K., and T. D. Paine. 1988. A degree-day model to predict Nantucket pine tip moth, Rhyacionia frustrana (Comstock)(Lepidoptera: Tortricidae), flights in Southern California. Environ. Entomol. 17: 75-79.