Nantucket Pine Tip Moth is a major insect pest of intensively managed pine plantations throughout the Southeast. It infests loblolly, shortleaf and Virginia pine and occasionally attacks longleaf and slash pine. Genetically improved seedlings have a low threshold for insect damage. Nantucket Pine Tip Moth infestations can significantly reduce the early growth that the latest genetic improvements were designed to capture and lower growth and yield at the end of the rotation.
THE PROBLEM
Tip moth infests pine seedlings and young trees. Infestations are most common and severe in the first and second year after planting. It has little impact on trees that are more than 6 years old.
Pine tip moth larvae feeding kills the terminal buds and tips of shoots. Attacks are most common on the terminal leader and upper branches. There are 2 to 5 generations per year coinciding with new flushes of growth. Stunting and deformation of the seedlings occurs, resulting in growth reduction, that delays growth to merchantable size and extends rotation length. In severe infestations, seedling mortality can occur. A common lesson of pine management is that early growth losses cannot be recaptured during the rotation.
PRODUCTS TO USE
There are two new systemic insecticides that control Nantucket pine tip moth, CoreTect and PTM. CorTect is a tablet with a small amount of fertilizer that is placed in the hole during planting. PTM is a liquid that is diluted and injected into the soil either at the time of planting or shortly thereafter. It normally takes about a month for the seedlings to absorb and translocate either product. This means the seedlings can be susceptible to attack by the first generation of pine tip moth.
An advantage of PTM is that it can be applied to containerized seedlings in the nursery eliminating the field application cost. This also provides the advantage of protection of the seedling from the day it is planted.
RESEARCH
A study conducted by the University of Georgia highlighted the long-term effects of the Nantucket Pine Tip Moth on loblolly pine trees. Trees that were protected grew significantly faster and had better form compared to unprotected trees during the first six years after planting. Even after 15 years in Georgia and 20 years in North Carolina, the 30% volume difference between protected and unprotected trees continued to increase.
In Virginia, a study comparing PTM and CoreTect found both products significantly reduced tip moth damage in treated trees compared to untreated ones over two years. Seedling survival was also improved with both treatments. The combination of reduced damage and increased survival led to an average volume gain of 69% per acre.
Another study in Texas examined PTM use on containerized seedlings. Tip moth control was excellent in the first year, very good in the second year, moderate in the third, and diminished by the fourth year. Volume growth improvements ranged from 17% to 59%.
APPLICATION
PTM field applications offer flexibility, as they can be performed any time the soil is not frozen, ensuring year-round control in many regions. The application process involves using a backpack sprayer equipped with a specialized soil probe. This probe is designed to inject the PTM directly into the soil, targeting the root zone of the seedling for optimal absorption. By delivering the treatment at the root level, the active ingredients are absorbed by the tree’s vascular system, providing extended protection against pests like the Nantucket Pine Tip Moth.
It’s essential to follow label directions closely to ensure the proper dosage, application depth, and timing for effective pest control and tree health. Accurate application helps prevent potential environmental harm, such as runoff or leaching, while maximizing the benefits of pest protection and promoting healthy seedling growth.
Azelis A&ES has experienced representatives that can help you make the right decision for your land management objectives. We are ready to provide you with a safe and effective solution. Talk to one of our technical experts to get started today!