THE CANADIAN ENTOMOLOUIST. 259 



therefore, varies from 9 days 12 hours to 13 days 2 hours, though the 

 average (10 days 8 hours) is represented by the minimum more nearly 

 than by the maximum. 



Larval Life. — The newly-hatched larva does not make a meal of the 

 deserted egg-shell, though in eating its way out it may devour the eniire 

 top. More frequently, however, it is satisfied to make a hole only large 

 enough to crawl through, usually in the top, thus destroying a part of the 

 niicropyle. 



The little caterpillars are stronger and more vigorous than those of 

 the related species, and crawl about at a speed that argues well for their 

 future good health. Making their way among the tough hairs (?) which 

 bind together the sheaths containing the needle clusters, they fasten upon 

 the side of a sheath and bore through it a minute hole, enabling them to 

 reach the tender tissue of the needles upon which they feed (fig. 2). 

 Into this hole the head is thrust, and the larva excavates as much of the 

 interior as it can reach without getting its body inside.* It makes a new 

 puncture whenever necessary, and by these the presence of the caterpillar 

 may often be detected. The excrement is usually in the form of pellets, 

 which occasionally lodge among the scale leaves, and so serve to indicate 

 that a larva is at work. Sometimes the excrement is in strings, and if 

 these lodge on the shoots one may find the caterpillar without difificulty. 



When first born the caterpillar is yellowish-green or gray-green, but 

 soon becomes brown, marked with a creamy white line on the laterodorsal 

 lidge. This is an excellent protection at this time while the larva is feeding 

 on the brown needle bundles, and the same colour marks it with very little 

 change until after the second moult. When the needles begui to thrust 

 their ti])s beyond the sheath the caterpillar ascends to the lowest vi,ible 

 green tissue, and bores into it in a manner which causes the lip to drop 

 away. This wastefulness possibly protects the insect from enemies other 

 than the entomologist, but for him is a good guide in tiie search for cater- 

 pillars. (Fig. 3.) 



Soon after the second moult the larva becomes green, with pro- 

 nounced white stripes, and at the same' time alters its method of feeduig. 

 Ascending to the tip of a young needle, it begins to devour this, aid 



*With the first larvae raised in the laboratory I experienced some diflfiLulty. 

 Several of them insisted on boring- into the exposed stem, and were promptly 

 drowned in the sap which flowed from the wound. Dr. Jas. Fletcher writes me 

 that he has lost young- caterpillars from the same cause. This can hardly be 

 regarded as a natural point of attack, as it is invariably fatal. 



