16 College of Forestry. 
earliest males have prepared their nuptial chambers before 
the first females leave the larval host. 
During the past spring (1915) the first record of activity 
of P. hopkins: in the field is dated April 24th when a single 
male was found just completing the nuptial chamber in the 
bark of a white pine limb which had fallen during the 
winter. This was the only burrow found on a limb of two 
‘inches in diameter which was within 100 feet of a con- 
siderable quantity of pine tops and slash which had served 
as a breeding place during the preceding summer and 
which was well stocked with young adults. These infested 
limbs were examined and it was found that only a few 
specimens had emerged, although a week later nearly all, 
except those which from their color had transformed since 
the cessation of cold weather, had left. This definitely places 
the emergence of the overwintered adults as taking place 
during the last week in April for 1915. However as the 
past spring was considerably cooler than usual at Syracuse 
it is probable that emergence usually occurs somewhat earlier. 
Construction or THE EnrRANCE GaLtEery.— In most 
eases where detailed observations have been made of the 
construction of the burrow of bark beetles, it has been re- 
ported that this work has been started by the female in the 
ease of monogamous forms. The observations of H. A. 
Gossard (1913) of the habits of Hecoptogaster regulosus 
Ratz, and of Phloeotribus liminaris Harris, which are 
recorded in considerable detail establish this fact for the 
species he studied. In the case of polygamous forms, how- 
ever, this does not appear to be true. Niisslin (1913) says 
“Bei den polygamen Arten beginnt das Minnchen das 
Brutfrassbild, indem es den Einbohrgang und die Rammel- 
kammer nagt.” My own observations upon Pityogenes hop- 
kinst agree entirely with this statement. 
As has already been shown, the males emerge from their 
host plant slightly earlier than the females and immediately 
seek a Sithabils host and commence excavating a new burrow. 
They prefer to breed in recently cut limbs and tops of 
white pine but will attack standing, dying or dead pine 
