the canadian entomologist 123 



The Early Aspen-Leaf Curli;r. 



I 

 {Proteopteryx oregonana VVlshm.) 



The years 1917-18 were noteworthy, in an entomological sense, owing 

 to the abundance of three microlepidopterous leaf-curling larvie all of which 

 attacked aspen poplar, Populus iremuloides. One of these insects has already 

 iieen dealt with,* while the habits of a second are described below. 



The larval habits of the Early Aspen-leaf Curler are similar in many respects 

 to those of other leaf-curling species but unlike the other two prevalent during 

 the period mentioned above, complete their life the same season that they hatch 

 from eggs, instead of hibernating, while the moths dififer by emerging from over- 

 wintering pupce very early in the spring. In 1918, they were on the wing in 

 millions by the end of March. 



The moths are of a dull blackish-brown colour aboxe, indistinctly barred 

 with darker tints, the secondaries being lighter. They may be met with at any 

 time during the day when they rise from the leaves as one walks through the 

 woods. Usually, however, the time of greatest activity is towards evening, 

 approximately an hour before sunset until dark. It is then that they rise in 

 large swarms and fly backward and forward over the tops of the trees. This 

 is when the air is still. A very light breeze, however, is sufficient to force them 

 downward. It is due to the wind that they gather in the shelter of the woods 

 and drop sufficiently close to the ground to be watched with ease. Observed 

 under such circumstances they were seen to fly around the lower trees in a similar 

 manner to their movement about the higher ones but in addition to the general 

 habits on the wing they were also found to possess another one which consisted 

 of alighting upon a twig a foot or more from its extremity and then running to 

 the top where they would remain stationary for a few moments as if attempting to 

 secure nourishment from the bud, after which they would arise again to join 

 the flying swarm. The moths continued in their evening activities, whenever 

 the atmosphere was sufficiently warm, for more than a week before oviposition 

 commenced and remained in large congregations throughout most of the egg- 

 laying period. 



The eggs are flat, scale-like objects, of a dark clay-yellow and thus resemble 

 very closely certain marks always present upon the twigs. They are usually 

 deposited singly but occasionally three or more may be found slightly over- 

 lapping each other. In 1918, eggs were deposited from April 6 to approximately 

 the 20th. They are always found upon the smaller twigs and there seems to 

 be some attempt made to place them around the scars or buds where they are less 

 detected. With calm weather most of the eggs are laid on the higher trees but 

 otherwise they may be found comparatively close to the ground on quite small 

 trees, or near the tips of the low'er branches of larger ones. It is due to these 

 habits that certain clumps of trees may be almost entirely defoliated later on. 

 while others in the same neighborhood escape with comparatively small injury. 



Larvae usually begin to emerge towards the end of April and are numerous 

 a few days later. When they first appear the caterpillars are somewhat flattened 

 objects with a head exceeding the body in width. They are dull yellowish in 

 colour, with a black head and dark but duller thoracic shield. The larvae 

 become of normal cylindrical shape after moulting and change very little in colour 

 *The Agricultural Gazette of Canada, Vol. 5, No. 11, 1918. 



