Pandora Moth

PANDORA MOTH

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information: JA

PUBLICATIONcurrent

nfestations of pandora moth {Colomdia pandora) periodically de- mostfoliate trees in forests and urban landscapes in central Oregon. THIS . Pandora moth larvae (caterpillars) feed primarily on the needles of ponderosa and lodgepole pines, and they cause severe growth For loss—even tree death. This publication provides information on identification, life cycle, http://extension.oregonstate.edu/catalogand control methods for pandora moth for home and forest owners. Stephen A. Fitzgerald, area Extension forestry agent, central Oregon (Deschutes, Crook, Jefferson, and Grant counties and Warm Springs Reservation), Oregon State University.

ORGGON STATG UNIVGRSITY GXTGNSION SGRVICG 'l EC 1383 • February 1992 Identification Adults are large, heavily- bodied, grayish-brown moths with a wingspan of 2.5 to 4 inches. Fore- and hindwings have a distinctive black spot. Hindwings are rose-colored (figure 1). Male moths have large, yellow, featherlike antennae; female antennae are also yellow, but not featherlike. Newly hatched larvae DATE. have shiny black heads and black or brownish bodies with short, dark hairs. Larvae are about 1 inch long OF in late fall (figure 1) and may grow to 1.5 inches by late winter. By early summer the next year, larvae are about 2 inches long, yellow- ish-green in color, with a OUT few stout-branched spines on each body segment. Figure 1.—Pandora moth (above) and caterpillar (below). IS The population continues to increase for a total of Life cycle three or four generations (6 to 8 years) before the The pandora moth population crashes, which requires 2 years to complete usually happens when the the four stages of its life population becomes in- cycle: egg, larva, pupa, information: fected by a naturally moth (figure 2). Adult occurring virus. moths appear in June or early July. Most of the moths fly at night, but male moths can Tree symptoms often be seen flying around and impact during the day in search of mates. When populations current The larvae feed on needles are high, moths can some- in the fall of the first year and times cover the sidesPUBLICATION of spring and early summer of buildings, swarm around the second. In spring, on streetlights, and become a heavily defoliated trees, nuisance to homeowners. crowns (area of live foliage) Eggs are laid in Julymost and lars are difficult to see and moths emerge and mate to can appear thin, and the/re August on foliage, bark, often go unnoticed. complete their 2-year life sometimes totally void of and THISthe sides of buildings The larvae resume feeding cycle. needles because the old and other structures. The in early spring (March-April) foliage has been consumed young larvaeFor hatch in late of the next year, and continue and new needles haven't yet August and September and feeding until late June or Population cycle emerged (figure 3). climb up into trees and early July. Caterpillars then Trees are refoliated begin feeding on needles.http://extension.oregonstate.edu/catalog move down the tree and Pandora moth infestations because new growth occurs During winter, the young burrow in the soil, where build up to epidemic propor- immediately after defolia- larvae hibernate in clusters they form a pupa (transform tions over several genera- tion and because trees have at the base of needles. from caterpillar to moth), and tions. Studies in Arizona a chance to grow new During mild winters, they remain through winter and showed that pandora moths needles the next year, when may periodically resume spring. increase from endemic (low) the insects are pupating in feeding on warm days. At In late June or early July of to medium or high levels the soil and no feeding this early stage, the caterpil- the second year, the adult after one or two generations takes place. (2 to 4 years). Severe defoliation can be which improves control. rather spotty, with severely Direct control Spray only when caterpil- defoliated tree clumps as No insecticide is specifi- lars are visible and actively large as 30 to 40 acres cally registered for the feeding. (figure 3). Severely defoli- control of pandora moth in Because pandora moths ated trees lose vigor and Oregon. Studies in Arizona are attracted to light, you diameter growth is reduced. found that the insecticide can prevent attracting them Nevertheless, trees Orthene was useful in to your property by keeping seldom die outright from controlling pandora moth in outside lights off until the pandora moth defoliation. the fall (October) of the first moth flight is over. However, defoliation in year, when larvae are in the combination with other early developmental stages. stress factors, such as mistle- There are several other Figure3.—Caterpillars eat the toe, drought, competition broad-spectrum insecticides older needles ofponderosa pine from other trees, and physi- that may be useful for trees (right), and they can DATE. cal damage can lead to tree controlling pandora moth completely defoliate an entire death. caterpillars around the stand (below). Severely defoliated trees home and in forested areas. OF could be at increased risk Consult your county office ______mam from bark beetles attacks, of the OSU Extension including mountain pine Service for a list of appro- beetle {Dendroctonus priate insecticides. ponderosae) and pine engraver Remember: Always read and dps pini). follow label directions! OUT Homeowners who want to spray trees on their property may want to hire a tree IS care professional with equip- ment capable of spraying tall Figure 2 Pandora moth has a trees. This will ensure even 2-year life cycle. and thorough coverage. information: Yearl Year 2 Life Stage I Moth Flight Moth flight Moth LayPUBLICATION eggs on trees and buildingscurrent First and second Instar 3rd, 4th, & 5th Instar Caterpillar

Light feeding Crawl Emerge from moston needles down tree pupa chamber THIS to soil ForAbove Ground

Burrow below duff and litter and pupate in mineral soil Pupa http://extension.oregonstate.edu/catalog

elow Ground C?Stay below ground 12 months; no feeding I I I I I I I I I I I I I I I I I I I I I I I ONDJFMAM JJASONDJFMA M J J A S Months Mountain pine beetle Home owners However, wait to thin If you're a homeowner, your stand until the follow- Use pesticides safely Because defoUated trees you may want to spray the ing year after defohation, so may be at greater risk to affected trees to prevent the trees have time to regrow • Wear protective clothing mountain pine beetle, you further defoliation. their needles. This will also and safety devices as may want to use a preventive In addition, if the defolia- make it easier for you to recommended on the la- insecticide to reduce the tion is severe, you may want determine which trees have bel. Bathe or shower after chance of beetle attack. to fertilize affected trees to survived. each use. To provide 1 and perhaps improve their vigor. Use a When you thin, select the • Read the pesticide 2 years of protection against fertilizer high in nitrogen. most vigorous trees in your label—even if you've this pest, there are pesticides This treatment provides the stand, providing a 16- to 18- used the pesticide before. that you can apply to the necessary nutrients for the foot spacing between leave Follow closely the trunk of defoliated trees in tree to regrow its needles. trees. Trees that are vigorous instructions on the label the spring. See EC 1085 for For proper coverage, generally have the largest (and any other directions more information. Since this DATE. fertilize outward from the crown area (green foliage) you have). treatment is expensive, spray base of the tree to three times when compared to other • Be cautious when you only high-value trees, such as the radius of the tree's crown. trees within the same stand. apply pesticides. Know those in home landscapes For example, if the radius of Good candidate leave your legal responsibility and in campgrounds. OF the tree's crown is 4 feet, trees should also: be straight, as a pesticide applicator. evenly apply the fertilizer out have good form, and be free You may be liable for to 12 feet around the tree. of other insects, pests, and injury or damage result- Improving tree This ensures the entire root disease. ing from pesticide use. system is fertilized. recovery after You can use granular OUT defoliation fertilizer and fertilizer "spikes"; they're sold in most For further IS This publication was partially funded When heavily defoliated, farm and garden stores. For reading by monies from the Stewardship specific fertilizer rates, see trees use a considerable Capizzi, Joe, Mountain Pine Program, Oregon Department of your county Extension agent. Forestry. The Stewardship Program amount of energy to regrow Bark Beetle: Protecting new needles. This depletes is part of the Forest Stewardship Act Forest owners Individual High-Value of 1990. Its purpose is to stimulate food reserves and reduces Pine Trees, Oregon State integrated management of other the tree's ability to withstand If you're a forest land- University Extension natural resources with timber on other stresses, such as insects, owner, spraying and fertiliz-information: Service Circular 1085 nonindustrial, private forest land. disease, and drought. ing an entire stand of trees is (CorvaUis, 1981). No Extension Service, Oregon State You can take several steps costly. If defohation to your charge. to speed recovery and boost trees is light, no special treat- University, CorvaUis, O.E. Smith, This publication (and director. This publication was tree vigor under varying ment is needed nor practical. the one you're holding, EC produced and distributed in further- levels of defoliation. If your stand of trees is ance of the Acts of Congress of May 8 severely defoliated (that is, 1383, Controlling Pandora and June 30,1914. Extension work is a most of the needles cosumed), Moth in Central Oregon cooperative program of Oregon State Forests and Landscapes, 75t) University, the U.S. Department of you may want to consider Agriculture, and Oregon counties. thinningcurrent the stand. Thinning are available from Publica- PUBLICATIONprovides more water, tions Orders, Agricultural Oregon State University Extension nutrients, and sunlight to the Communications, Oregon Service offers educational programs, State University, Adminis- activities, and materials—without remaining trees and, there- regard to race, color, national origin, sex, fore, improves tree vigor. trative Services Bldg. 422, CorvaUis, OR 97331-2119. age, or disability—as required by Title most VI of the Civil Rights Act of 1964, Title IX of the Education Amendments of THIS 1972, and Section 504 of the Rehabilita- Shipping and tion Act of 1973. Oregon State handling University Extension Service is an For Equal Opportunity Employer. For orders up to $3.50, please include 50c. For http://extension.oregonstate.edu/catalogorders between $3.50 and $100, include 15%. 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