52 MISC. PUBLICATION 273, U.S. DEPT. OF AGRICULTURE 



death of the terminal growth. Rhyacio?iia zozana (Kearf.) does 

 similar work in the ponderosa and Jeffrey pines in the Sierra 

 region of California. It is especially damaging to nursery stock and 

 pine seedlings and saplings up to 6 feet in height growing in open 

 stands unshaded by mature trees. R. montana (Busck) does simi- 

 lar injury to the buds and twigs of lodgepole pine in Idaho and 

 Montana. 



PITCH NODULE MOTHS 



The pitch nodule moths, belonging to the genus Petrova, while 

 in the caterpillar stage, bore into both the new and old growth of 

 pine stems, twigs, and branches. Their work is characterized by a 

 nodule or round dirty lump of pitch and frass, which is formed at 

 the point of attack. They do not attack the buds but usually work 

 at nodes or whorls of branches, and finally pupate within the pitch 

 nodule. Trees are seldom, if ever, girdled by the larval channels 

 but many are so badly weakened that the tops are broken by wind 

 or snow. The moths are speckled with brown, yellow, or gray 

 markings and have a wing expanse of about % inch. The follow- 

 ing species are found in the Western States : 



Species of Petrova Hosts and distribution 



albicapita7ia (Busck) Lodgepole pine. Idaho, Montana, Washington, 



and east to New England, also Canada. 

 burkeana (Kearf.) Sitka and Engelmann spruce. Washington and 



Montana. 



edemoidana (Dyar) Ponderosa pine. Arizona and New Mexico. 



luculentana (Hein.) Ponderosa pine. Colorado. 



metallica (Busck) {fig. 20) . . Lodgepole and ponderosa pines. California to 



Montana. 

 monophylliana (Kearf.) .... Singleleaf pinyon. California. 

 picicolana (Dyar) Alpine and grand firs. Washington, Idaho, 



British Columbia, and California. 

 sabiniana (Kearf.) Digger pine. California. 



PINE SHOOT MOTHS 



The caterpillars of the pine shoot moths, belonging to the genus 

 Eucosma (66), bore through the pith of terminal shoots and lead- 

 ers and into cones of various coniferous trees. Owing to the 

 drooping of the dead lateral shoots the damage is often referred 

 to as tip droop. The terminal leaders of young, thrifty trees are 

 seldom killed, but the grow T th may be shortened. Eucosma sono- 

 mana Kearf. in the larval stage bores through the pith of the 

 terminal twigs of ponderosa pine and Engelmann spruce. E. bo- 

 bana Kearf. is an ochreous-colored moth with white spots on the 

 forewings and a wing expanse of about 1 inch. The larvae have 

 been found boring through the pith, cones, and seeds of ponderosa, 

 Jeffrey, and knobcone pines in California and Oregon. E. rescis- 

 soriana Hein. is a dark brick-red moth with faint sprinklings of 

 black scales, and a wing expanse of about % inch. The larvae feed 

 through the pith and cones of lodgepole pine in California and 

 Oregon. 



The caterpillars of the Monterey pine shoot moth (Exoteleia 

 burkei Keiff.) mine the developing shoots of Monterey pine, caus- 



