468 MISC. PUBLICATION 657, U. S. DEPT. OF AGRICULTURE 
duced on nursery stock from Nebraska. The food plants include all 
species of the two- and three-needle pines, or hard pines, with the 
exception of slash pine and possibly longleaf pines. Records indicate 
there may be one generation a year in Massachusetts, two in Pennsyl- 
vania, northern Vir ginia, and Nebraska, and four or more in Louisiana 
and Texas. In the North the moths are active during May and early 
June; in the region having two generations the moths are active from 
about the middle of April to the middle of May, and again in late June 
and early July; and in the South they are active during February to 
March, May, July, and August to September. 
The eggs are circular, flattened, and light yellow, and are usually 
laid singly on either the needles, buds, or shoots. On hatching, the 
larva begins to feed on a new shoot near the base of the needles or the 
base of a bud, sometimes penetrating the needle fascicles. A protec- 
tive web is spun over the place where the larva is feeding, and this in 
turn soon becomes covered with pitch. Later the larva bores either 
into a bud or the succulent growth near the tip of the shoot, and con- 
tinues to mine until it has completed its development. A light silken 
cocoon is spun in the burrow in which the larva pupates. The length 
of the larval stage varies according to the geographical range and the 
climate, but records indicate it is never less than 3 weeks, and may be 
5 weeks in the North. Winter is passed in the pupal stage. In the 
Eastern and Southern States Rhyacionia frustrana pupates within the 
injured twig tip, but the form bushnelli in the Midwestern States drops 
to the ground at the end of the last generation and transforms in the 
litter or soil. This is a serious pest of seedling and sapling pines, in 
nurseries, plantations, or natural stands, but after the trees reach a 
height of about 25 feet they are not ser iously injured. It mines the 
tips of the twigs, which causes deformity in growth and loss in height 
increment, and where heavy infestations persist over a period of years 
some of the less vigorous trees succumb, For further information on 
this pine tip moth, see Packard (323). 
It has been observed in the Central States that hard-pine plantations 
in the proximity of native yellow pine stands usually suffer relatively 
little damage from the tip moths, owing to control by native parasites. 
A few years ago Campoplex frustranae Cush., a hymenopterous para- 
site of Rhyacionia frustrana in the Eastern States, was introduced into 
plantations in Nebraska which were heavily infested with R. frustrana 
bushnelli. Tt became established readily and has aided materially in 
bringing about the control of this pest. As a general measure of con- 
trol, “avoid planting infested stock, particularly i in areas where the tip 
moth is not already present. The utilization of fast-growing stock 
and restriction of planting to better sites will assist the trees 
in outgrowing the tip moth injury. After the tip moth has become 
established in a stand of hard pine, it is practically impossible to 
eradicate it. The removal of infested tips in young stands will aid in 
reducing the infestation, but this is expensive, particularly in regions 
where tere are two or more generations a year. 
Rhyacionia rigidana (Fern. ) has a wing expanse of about 84 inch, 
and the forewings are similar to those of R. frustrana, except that the 
gray bands are more extensive. The larva and its habits are also 
similar to those of R. frustrana. Its distribution is from New York 
to West Virginia and North Carolina. The food plants are red, pitch, 
