THE DOUGLAS SPRUCE CONE MOTH 129 



-noon. It is well known that the codling moth prefers the warm, 

 •early evening houirs for egg-laying. 



Wheth'er the cones remain on the tree during the winter or 

 •drop to the ground in the fall is apparently rather imma'terial to the 

 insect. Sargent, in his "Silva of North America," states that the 

 cones "mostly fall ofif as soon as their seeds have escaped in the 

 autumn." The writer believes that fully one-half of them may be 

 found on the trees in the spring, but they are easily removed with 

 the hands either in the late fall or early spring. It is certain that 

 large numbers of moth-infected cones drop off in the fall. We have 

 picked them up in baskets for the purpose of getting material from 

 which to rear parasites, but since practically all on both the ground 

 and the trees alike were infested by the larvae, we are unable to 

 state whether the presence of the insects tends to make the cones 

 hang longer or drop quicker, or whether they have no eflfect in this 

 respect. The eggs are laid directly on the young cones and in our 

 alcoholic material they are all to be found on the bracts, none being 

 on the scales. At the time the eggs are laid, as later, the surface- 

 of the bracts as seen under a hand lens, is very m,uch smoother than 

 the surface of the scales. It is not surprising, therefore, that the 

 eggs are laid on the smooth bracts, for it is well known that the 

 codling moth females prefers to deposit her eggs on a smooth glossy 

 surface such as may be found on the upper surface of the leaves or 

 on the polished surface of a half grown apple. 



The egg is flattened, with a flange around the edges, and with 

 the central portion more convex, nearly colorless, glossy and with 

 irridescent reflections, i mm. in length, by one-sixth less in width; 

 upper surface with irregular reticulations. Several eggs may be 

 found on a single cone. The length of the period of incubation has 

 not been determined. 



In the summer of 1907 the eggs were laid during the last week 

 of June, and the small caterpillars were to be found in abundance 

 in the cones on the ist of July. Three larvae were found in a single 

 cone in alcoholic material taken, on July,.2nd, and it is probable that 

 more than that number could be found in one cone. There seems 

 to be no definite point selected by the larva in entering the cone. 

 Sometimes an angular depression, where two scales meet, is selected, 

 but a fully exposed spot may be used. The young caterpillar usual- 

 ly eats at first from between two scales, feeding both from' the one 



