40) MISC. PUBLICATION 273, U. 8. DEPT. OF AGRICULTURE 
braska. The moths measure about 1 inch in wing spread. The base 
of the front wings is dark gray and the outer third reddish orange. 
The larvae, when full grown, are nearly three-fourths of an inch long 
and reddish. ‘There is but one generation annually. The moths fly 
in April and May in most localities, but in the latter part of May 
and early in June in the Black Hills. The full-grown larvae leave 
the tips during July and spin cocoons, usually in the bark crevices on 
the base of the tree below the litter. Here they transform to pupae 
and pass the remainder of the season and the winter. Infested tips 
can be identified, after the larvae leave, by the dead, partially de- 
veloped needles toward the apex of the shoot, and by the fact that this 
part of the shoot, and usually the buds, have been riddled by the 
larval burrows and crumble readily when dry. 
Rhyacionia pasadenana Kearf. is a silver-gray moth with reddish 
markings and a wing spread of five-eighths of an inch. In the 
caterpillar stage it bores through the buds and twigs of Monterey 
pine, ponderosa pine, and probably other pines in California, causing 
a pitchy exudation and the deformation or death of the terminal 
growth. It has recently been found attacking ponderosa pine seed- 
lings and saplings up to 6 feet in height, where these are growing in 
open stands unshaded by mature trees, on cut-over lands in eastern 
California. 
Rhyacionia montana Busck does similar injury to the buds and 
twigs of lodgepole pine in Idaho and Montana. 
PitcH NopuLe Morus 
The pitch nodule moths belonging to the genus Petrova (Fvetria), 
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 
often are so badly weakened that the tops are broken by wind or 
snow. The moths are speckled with brown, yellow, or gray mark- 
ings and have a wing expanse of about three-fourths of an inch. 
The following species are found in the Western States: 
Species of. Petrova Hosts and distribution 
P. metallica Busck (fig. 17)--_._ Lodgepole and ponderosa pine. California 
to Montana. 
P.SQ0UTMONGANS Cari 2 Nee ee Digger pine. California. 
P. monophylliana Kearf_________. Singleleaf pinon pine. California. 
Bo tucitlentang. eins]. ==) —— si Ponderosa pine. Colorado. 
Po burkeane Keats ess a ae Sitka and Engelmann spruce. Washington 
and Montana. 
iPS DiC Colang. Dyars ss 2 ae White fir and alpine fir. Washington. 
P. albicapitana Busck=_2__-— == Lodgepole and ponderosa pine. Idaho and 
Montana. 
PINE PitcH Motruys 
The caterpillars of the pine pitch moths, belonging to the genus 
Eucosma (39), bore through the pith of terminal shoots and leaders 
and cones of various coniferous trees. Owing to the drooping of the 
