Defoliation of Sacramento Mountains
The western portion of the Sacramento Mountains on the Lincoln National Forest has experienced two successive years of tree defoliation by an infestation of a winter conifer species, Nepytia janetae. The Lincoln National Forest Supervisor has authorized aerial spraying to suppress Nepytia janetae winter conifer defoliation. Approximately 4,419 acres of National Forest System Lands around the Village of Cloudcroft, New Mexico, are going to be treated in November 2007, with a tentative second application planned for March 2008. The preferred control agent using an aerial spray application is the biological insecticide Bacillus thuringiensis var. kurstaki (Btk). Based on research and consultation with Forest Service entomologists from multiple regions, the preferred control agent Btk is a naturally occurring bacterium that has been effective in controlling the larval stage of other lepidopteran (moth or butterfly) forest pests such as gypsy moth and Douglas-Fir tussock moth. It has been proven to pose no risk to human health or municipal water supplies and will not negatively impact other mammal, bird or fish species. For further information contact: Lincoln National Forest, 1101 New York Avenue, Alamogordo, NM 88310, (575) 434-7200.
Looper Treatment Area Map Link
BTK Foray Links
BTK Foray Commonly asked questions
NEPYTIA JANETAE (Fir Looper)
Identification: Nepytia janetae (no common name) is a moth in the family Geometridae, loopers or inchworms.
Hosts in Southern Sacramento Mountains of South Central New Mexico: The Nepytia janetae moth exclusively prefers conifers and actually feeds on several species of conifer trees but mainly, Douglas-fir and white fir.
Effects: Larvae feed on host foilage, sometimes completely defoliating trees. Most of the feeding by Nepytia janetae takes place on the margin of the conifer needle, creating a serrated appearance. Although the needle remains on the tree, the damage causes subsequent desiccation and death of the needle, lending a scorched appearance to the crown. While the red needles are retained in the crown, they are characterized by wildland fire experts as aerial "flashy fuels". When the needles drop, this effect ceases. They are capable of defoliating entire stands or preferred host components. Tree mortality can be due to defoliation alone or due to secondary infestation by bark beetles.
Ecological Role: Nepytia janetae is a native species to New Mexico and Arizona. Recent outbreaks of the same species occurred in the White Mountains and Pinaleno Mountains of Arizona in the late 1990's. Very little is known on what ecological role Nepytia janetae plays in the forests of the Southwest.
Life History: Adult moths appear in late June, peak flight is reached in early July. Eggs are typically laid by the female moths on the upper branches of the host trees. Eggs hatch in late September. Early instar larvae spin silk threads and may be blown considerable distances in the wind, distributing the population over wide areas. Larvae feed throughout the winter and spring.
Conducive Habitats: Old growth and mature subalpine and mixed conifer forests appear to be the most conducive habitat for Nepytia janetae outbreaks. Outbreaks appear to be related to favorable climatic conditions such as drought and mild winters.
Management: Very little is known about what management is effective against the Nepytia janetae. U.S. forest Service specialists have been monitoring the situation since the outbreak began. Currently, there is no research or evidence to support tree thinning as a means of reducing spread during outbreaks. Forest Service is experimenting with the use of systemic insecticide plugs in selected trees within area campgrounds to determine their effectiveness against the insect.