SEQUOIA PITCH MOTH Integrated Pest Management for Home Gardeners and Landscape Professionals The sequoia pitch moth, Synanthedon rarely kills trees. Larval feeding some- sequoiae, occurs from California north times causes one or more limbs to die or through British Columbia. This clear- become weak enough to break, espe- wing moth (family Sesiidae) infests cially if infested trees are young. Pines most conifer species, including Douglas with pruning wounds or other injuries fir, pines, and spruces. In California it are more frequently attacked than unin- most often attacks pines, especially jured pines. Damage is prevalent in those in urban coastal areas of northern certain pines planted in landscapes, California, from Monterey Bay to the such as Monterey pine (Table 1). San Francisco Bay Area. A similar clear- wing species, the Douglas-fir pitch IDENTIFICATION moth (Synanthedon novaroensis), infests Infestations are recognizable by the Douglas fir, pines, and spruces from gray, pink, reddish, or yellowish pitch northern California to Alaska. masses that protrude from infested trunks and limbs. Pitch masses initially DAMAGE are small, soft, glistening, and reddish Figure 1. Differences in appearance of a bark beetle pitch tube (left) and a Sequoia pitch moth is primarily an aes- brown to pink. As the larva feeds and sequoia pitch moth pitch mass. Bark thetic pest. The main effect of larval grows beneath each mass, the gummy beetle pitch tubes have a distinct round feeding is to cause infested pines to exudate enlarges, hardens, and becomes hole in their center, whereas the pitch produce copious amounts of unsightly darker gray. A brownish pupal case mass of the sequoia pitch moth often resin. Sequoia pitch moth larvae cause may protrude from the mass after the lacks a distinct emergence hole. very little injury to cambium and wood. larva has matured and emerged as an This relatively minor damage does not adult. Old pitch masses can remain on masses are often reinfested because egg- usually cause girdling of the trunk and bark for several years. Abandoned pitch laying females are attracted to these in- jury sites. Table 1. Relative Susceptibility of Pines (Pinus spp.) to Sequoia Pitch Moth. People unfamiliar with the damage sometimes confuse pitch moth pitch COMMON NAME SCIENTIFIC NAME masses with bark beetle pitch tubes MOST SUSCEPTIBLE (Fig. 1). Bark beetle pitch tubes are usu- Afghan, Allepo, Brutia, Calabrian, P. brutia, P. eldarica, P. halepensis ally less than 1⁄2 inch in diameter and Mondel, Turkish, and others1 typically have a distinct round hole in Bishop P. muricata the center made by an adult beetle. Bark Japanese black P. thunbergiana beetle pitch tubes often resemble the end Mexican P. patula Monterey P. radiata of a large gummy drinking straw pro- Ponderosa P. ponderosa truding from bark. Sequoia pitch moth Shore or Beach P. contorta masses are much larger and vary in shape from roundish to elongate oval. LEAST SUSCEPTIBLE Canary Island P. canariensis Italian stone P. pinea Resinous ooze from pine bark can have other causes, including Diplodia canker, Pines are more susceptible to pitch moths if pruned or otherwise injured. western gall rust, injuries such as prun- 1 Various common and scientific names are used for these closely related Asian and ing wounds, and the serious pitch canker European natives. Many species are quite susceptible, but their susceptibility varies and confusion among names makes them difficult to distinguish. disease, which is caused by the fungus Adapted from Frankie et al. 1986. Fusarium circinatum (=F. subglutinans f. sp. pini). Unlike the distinct protrusions PEST NOTES Publication 7479 University of California Agriculture and Natural Resources Revised March 2004 March 2004 Sequoia Pitch Moth moth biology, life history, and manage- ment are similar to those of sequoia (actual pitch moth. size) LIFE CYCLE Because not all individuals emerge (actual from pupae at the same time, adult size) moths can be present anytime from Adult Egg May through early September. Adults emerge earlier at warmer inland sites, and later at cooler sites near the coast. (actual Peak moth emergence occurs in June size) and July. Adults live only a few days, Pupa during which they mate and females lay eggs. Eggs are laid individually on bark, usually in crevices around prun- Larvae ing wounds and other injury sites. Eggs are 1⁄16 inch in diameter, reddish brown, oval, and somewhat flattened. They hatch in about 2 weeks. The dirty white, grayish, or pink larvae feed for several (actual size) months, excavating a shallow cavity that penetrates the inner bark to the Figure 2. The stages and life cycle of sequoia pitch moth. cambium surface of wood. After feed- ing, about one month is spent in the pupal stage. The dark brown pupae are caused by bark beetle pitch tubes and and Pest Notes: Pitch Canker listed in about 3⁄4 inch long and occur in silk- sequoia pitch moth pitch masses, inju- Suggested Reading. lined chambers within the pitch mass. ries, and pathogenic diseases usually Before adults emerge, the pupae force cause bark to become coated with a thin Sequoia pitch moth adults are day- about half of their length through the layer of resin resembling thick syrup. flying moths distinguished from other pitch surface, leaving a brown, paper- Bark discolors due to pitch canker; bark moths by their mostly clear wings. The like case after they emerge. Although a around beetle and pitch moth attacks is wings have bluish black margins with few individuals may complete their not discolored. Pitch canker can infect some yellow at the base. The moth’s development within a year, most se- pine tissue of any age, including young head and thorax are brownish black, quoia pitch moths require 2 years to branches and terminal shoots the diam- with some yellow. The legs are mostly develop from egg to adult (Fig. 2). The eter of a pencil; bark beetles and se- bright yellow. The abdomen is covered insect spends most of its life in the lar- quoia pitch moth primarily attack the with blackish and yellow hairs in alter- val stage. main trunk, though sometimes large nating bands, resembling that of a yel- limbs several inches in diameter can lowjacket wasp. Females are somewhat MANAGEMENT also be attacked. Yellow and red dying larger and plumper than males. Unlike Protect trees from injury. Moths prefer and dead branches scattered through- females, male clearwing moths have to lay eggs on bark near pruning out the tree are a characteristic symp- many fine hairlike projections along wounds and other injury sites. Provide tom of pitch canker, eventually their antennae. The adult’s body is trees with proper cultural care (espe- followed by death of the entire pine about 3⁄4 inch long with a wingspan of cially appropriate irrigation) to reduce tree; branches rarely die from sequoia 3⁄4 to 11⁄4 inches. Although the colors the frequency of borer attack and in- pitch moth. Depending on the species and erratic flight behavior of adults crease the trees’ ability to tolerate dam- of bark beetle and other factors affect- resemble those of paper wasps, clear- age. Carefully scrape away pitch ing tree health, branch dieback (from wing moths are not wasps and are masses to expose and kill larvae. No the red turpentine beetle) is rare, or stingless and harmless to people and other control aside from minimizing dieback appears first only at the tree pets. injuries to trees is recommended. Pines top (due to Ips beetles), or the entire tree are not seriously harmed by this insect. fades and dies (from Dendroctonus spp. The adult Douglas-fir pitch moth is and others) without being preceded by bright orange and blackish, instead of Sticky traps baited with clearwing moth scattered branch dieback. For more yellow and dark colored as with se- pheromone (sex attractant) are commer- information, see Pest Notes: Bark Beetles quoia pitch moth. Douglas-fir pitch cially available for monitoring the sum- ◆ 2 ◆ March 2004 Sequoia Pitch Moth mer flight period of adults. However, Keep weed trimmers and lawn mowers Physical Control such traps are primarily used to time away from trunks; for example, main- Scraping away or prying off resinous the application of insecticides, and no tain a several-foot-wide area around pitch cankers is the only direct method effective insecticides have been found trunks free of turf and other vegetation. of controlling pitch masses and larvae, for controlling sequoia pitch moth. Protect trunks from other sources of except possibly for pruning off smaller injury, such as from vehicle bumpers. branches. If resin masses are carefully Cultural Control excised, larvae or pupae can be found Small limbs infested with larvae and Plant only species that are properly and killed. Properly removing pitch pitch masses can be pruned off, but this adapted to the area. Certain pines are masses from all nearby trees, along may lead to future infestations around much less susceptible to sequoia pitch with appropriate cultural practices, can the pruning wound. If pines must be moth than others. Consider planting a reduce reinfestations and control local pruned, prune only from October more resistant species (Table 1). Learn clearwing moth populations. Inad- through January so that injuries begin to the cultural requirements of pines and equate application of pitch mass re- close before the egg-laying adults provide proper care to maintain vigor- moval technique allows the larva or emerge in spring. Prune in a way that ous growth. Appropriate irrigation is pupa to survive and mature into an enhances wound closure, such as by especially important to tree health. Inap- adult that can reinfest trees. Only one making cuts just outside the branch propriate watering is probably the most larva or pupa occurs in each pitch mass, bark ridge.