466 MISC. PUBLICATION 657, U. S. DEPT. OF AGRICULTURE 
growing plants, several are leaf tiers, some are exposed feeders on the 
leaves or flowers, and a few are leaf miners. 
The following discussion of species of this family which are forest 
pests of more or less importance, illustrates the wide differences in 
habits of the different species. 
The European pine shoot moth (hyacionia buoliana (Schiff.) ) is 
rusty orange red, with whitish legs, and has a wing expanse of about 
34 inch. The forewings are marked with several irregular forked 
silvery cross lines, and the hind wings are a plain dark brown. The 
egg is small, flat, and yellowish w hen first laid, but later it turns a 
reddish brown. The larva is brownish, with the head and thoracic 
shield black, and when fully grown it is about 5 inch in length. The 
pupa is about 38 Inch in leneth and chestnut brown. 
This insect is an introduction from Eur ope, first recorded in the 
United States in 1914, when it was reported as having caused serious 
injury to Scotch pine on Long Island, New York. Busck (77) re- 
ported that it had been discovered in nine States, principally in nurs- 
erles. It is now known to occur from Massachusetts south to Vir- 
ginia and west to Hhnois and Michigan, and Nova Scotia, southern 
Ontario, and British Columbia. Red, mugho, Scotch, and Austrian 
pines seem to be the most favored host plants in the Northeastern 
States. Many other species of pines are also attacked, and some of 
these too may prove to be favorable hosts if the insect becomes more 
widely distributed in the natural ranges of these trees (Busck, 77, and 
Friend and West, 777). 
There is one generation a year. The moths issue during June and 
early in July. “The eggs are deposited near the tips of the twigs, 
either on a needle sheath or the twig itself. They hatch in about ‘10 
days, and the young larvae bore into ‘the bases of the needles. Dui ing 
the latter part of the summer the larvae leave the needles and bore 
into buds. The injury to the buds causes a flow of pitch which hardens 
over the larval burrows. Hibernation takes place either in the bud 
or unde a mass of pitch on the bud. At this time the larvae are 
about 34, inch long. In the spring the larvae bore into other buds or 
the developing shoots, usually killing them. They attain full growth 
in May. Pupation takes place in the burrow, the pupal stage lasting 
about 18 days. 
In the United States the European pine shoot moth is a serious 
pest in nurseries, on ornamentals, and in plantations. In plantations 
it ceases to be a real menace after the crowns close. The destruction 
of the terminal and lateral buds and new shoots causes a malformation 
of young trees and a retardation of growth. In severe infestations 
the wholesale destruction of buds and shoots causes the development 
of adventitious buds, and as a result bushy tips are formed in place 
of normal growth. Often the injured shoot survives but bends or curls 
at the point of attack, thus causing a permanent crook or “post horn” 
in the leader or lateral, as the case may be (fig. 106). 
The larvae are susceptible to subzero (Fahrenheit) temperatures, 
and north of the annual minimum isotherm of —10° F. the frequent 
occurrence of low winter temperatures should keep the population of 
the insect down to a harmless level. In the northern range in young 
plantations or where Pinus mughus is used in ornamental plantings 
the infestation is often perpetuated because of snow protection dur- 
ing periods of severe cold. Parasites from its native habitat in 
