454 EXPERIMENT STATION EECOED. 



should be taken to tbe mill and ground in order tliat the numbers of the lars-ce 

 and pupai be reduced." 



A bibliography of 14 titles is included. 



American plum borer, B. B. Bolakeslee {U. 8. Dept. Ayr. Bui. 261 {1915), 

 pp. 13, pis. 3, fig. 1). — ^A report of biological studies of Euzophera semifuneralis. 

 conducted during 1913-14. 



This lepidopterous borer appears to prefer trees that are in a somewhat 

 weakened condition, such as those partially girdled by the disease commonly 

 known as collar blight or mechanically injured by frost. Without injury of some 

 sort to its host plant the borer rarely succeeds in establishing itself, and en- 

 tirely healthy and uninjured trees are in little danger from its attack. Where a 

 tree has suffered injury the work of this borer may, in many cases, considerably 

 shorten its life. Beginning at some scar, wound, or crevice, where a bark scale 

 offers partial protection, the larva works its way back into the living tissue, in 

 broad, shallow, irregular galleries just beneath the bark. It has been found 

 feeding upon plum, peach, cherry, Chinese plum (Prunus simoni), Kieffer pear, 

 mountain ash, persimmon, apple, and Russian mulberi"y. The author has found 

 it equally abundant on plum, cherry, peach, and apple. 



The insect is known to occur in 21 different States as far separated as the 

 District of Columbia, Arizona, and Washington. The species hibernates in the 

 larval stage under the bark scales in a tough cocoon of white silk at the entrance 

 of its feeding galleries. In the latitude of northern Virginia and the District of 

 Columbia in a normal season pupation commences about April 1. In the latitude 

 of Winchester, Va., the adults begin appearing the last of April or first of May. 

 Oviposition commences in from one to three days after emergence, from 12 to 

 74 eggs having been deposited by moths kept under observation in the laboratory. 

 At Winchester during 1913 eggs deposited the latter part of April and early May 

 required from 8 to 14 days for incubation. Eggs of the first generation appar- 

 ently begin hatching the early part of May and of the second generation about 

 July 1. Observations at Winchester of larva? which hatched on May 7 showed a 

 feeding joeriod of 34 days, a prepupal period of 2 days, and a pupal period of 10 

 days. 



The larva has a number of parasitic and predaceous enemies. Two parasites 

 reared at Winchester have been determined as Idechthis sp. and Mesostenus 

 thoraciciis. The former was the more common, some 13.47 per cenb»having been 

 parasitized by it. Itoplectis inarginatus, if. gracilis, and Pimpla sp. were reared 

 from borer larvae at Fort Valley, Ga., in 1905, and Tenebrioides corticalis has 

 been taken feeding upon them. 



It is thought that this borer will ijrobably never become a pest of more than 

 ordinary importance, except in occasional isolated cases. When the ordinary 

 precaution of cutting away the dead bark and painting the wounded areas is 

 followed, this may be regarded as sufiicient for the control of the borer. Where 

 the borer has established itself already, the cutting out method is the only one 

 that can be followed. 



A bibliography of 12 titles is included. 



Douglas fir pitch moth, J. Brunnek {U. S. Dept. Agr. Bui. 255 {1915), pp. 

 23, figs. 10). — It has been definitely determined that in the northern Rocky 

 Mountain and Pacific coast regions the Douglas fir pitch moth {Scsia nova- 

 roensis) is responsible for at least 90 per cent of that damage to Douglas fir 

 {Pseudotsuga taxifolia), known as pitch seams, gum check, windshake, etc., and 

 the same species appears to be responsible for the similar depreciation in timber 

 that occurs in the southern Rocky Mountain district. 



The loss occasioned by the work of this class of insects causes the difference 

 In price between absolutely clear lumber and the lower grades. They work in 



