Pine Tip Moth

Question:

I have had problems over the years with pine tip borers on my ponderosa pines. When should I spray and what should I use?

- S. G., Albuquerque

Answer:

Over the years we have discovered that the best time to spray for pine tip moth IN ALBUQUERQUE has been the first full week of May. The appropriate dates will differ in other parts of New Mexico. Some people spray a little before that (the last week of April or so) and have good luck since many of the chemicals used have a residual effect long enough to allow this.

If you spray later than the announced date, you may still kill the pine tip moth larvae, but they may have already done damage to the pine shoot tips, so the tree's first new growth may die. The tree will produce more buds in response, but if this happens every year, the shape of the tree will suffer.

If you spray late, use a chemical that is systemic (will be absorbed into the tissues of the tree). The usually recommended products for homeowners are Cygon (TM) and Orthene (TM). Some licensed spray companies use other products such as Talstar (TM) that is more benign in the environment for mammals and birds but, because it is very toxic to fish, is not available to the public. This product is not systemic, so timing is critical.

If you have birds nesting in the trees, you may want to consider hiring someone to spray this product. Tree size is another factor to consider according to NMSU's Extension Forest Entomologist, Bob Cain. He advises that any tree over 15-feet tall doesn't need to be sprayed. The moth larvae will infest the lower branches but will not bother the "central leader" sprout, the sprout responsible for the upward growth of the tree. Therefore, they will not harm the appearance of the tree and, for a tree at that size, are not likely to seriously deform the tree.

The reason we have this information in Albuquerque is that Master Gardeners have worked with the NMSU Cooperative Extension Service for almost 20 years to collect the data needed to properly deal with pine tip moth. In other parts of New Mexico, this data is not available. Bob Cain identifies Ponderosa, Afghan, Austrian, Scots, Mugho, and Japanese black pines as trees most likely to be affected by pine tip moths. He says that piñon pines and the five-needle white pines are less likely to be seriously damaged.

Also, please join us on Southwest Yard & Garden, a weekly program made for gardeners in the Southwest. It airs on KRWG in Las Cruces Saturdays at 11:30 a.m., repeating Thursdays at 1:00 p.m.; on KENW in Portales on Saturdays at 10:00 a.m.; and on KNME in Albuquerque on Saturdays at 9:30 a.m.

Marisa Y. Thompson, PhD, is the Extension Horticulture Specialist, in the Department of Extension Plant Sciences at the New Mexico State University Los Lunas Agricultural Science Center, email: desertblooms@nmsu.edu, office: 505-865-7340, ext. 113.

Links:

For more gardening information, visit the NMSU Extension Horticulture page at Desert Blooms and the NMSU Horticulture Publications page.

Send gardening questions to Southwest Yard and Garden - Attn: Dr. Marisa Thompson at desertblooms@nmsu.edu, or at the Desert Blooms Facebook page.

Please copy your County Extension Agent and indicate your county of residence when you submit your question!