THE WHITE-PINE WEEVIL. 735 



But such a number of youug weevils are usually placed in the affected 

 shoots that many of them are cramped and discommoded for want of 

 room. The worm on approaching the pith often finds there is another 

 worm there, occupying the very spot to which he wished to penetrate. 

 He thereupon, to avoid intrusion upon his neighbor, turns downward, 

 and completes his burrow in the wood outside of the pith. Those, also, 

 which enter the pith, are often unable to extend their galleries so far as 

 is their custom without running into those of others. When its onward 

 course is thus arrested, the worm feeds upon the walls of its burrow 

 until it obtains the amount of nutriment it requires and is grown to its 

 full size." 



The eggs of this species are probably similar in shape, but consider- 

 ably larger than those deposited by the timber beetles, whose eggs and 

 larval development are figured and described in the third report of 

 the United States Entomological Commission (p. 280, Plate xxii, figs. 

 1, 8, 9, 10. See also p. 722.) According to Ratzeburg, the European P. 

 notafus lays its eggs in the lower internodes of young plants, boring 

 into the sap-wood with Its beak. Its habits thus differ much from our 

 species, and it does not seem to aftect the terminal shoot. The grub or 

 larva does not differ from those of other borers found in the pine, as 

 there is a great persistence of form in boring grubs, both of the weevil 

 family and the bark-borers or Scolytids. The grub of Pissodes strobi 

 (Plate XXII, fig. 5) is rather slenderer than those of Rylurgus, Dendroc- 

 tonus, or Hylurgops pinifex. Compared with the latter very common 

 borer the body is 8°»'» in length, while that of R. jpinifex is only 5 to 6°^°^ 

 in length. 



While from their similar tunnel-making habits the larvte of the two 

 families mentioned are, owing to adaptation to their surroundings, very 

 similar, the pupae are very unlike, those of the white-pine weevil being 

 at a glance distinguishable by their long snout, which is folded on the 

 breast, and the beetle, as seen in the figure, has a long, slender snout, 

 while the body is reddish brown, with two irregular white spots, one 

 behind the middle of each wing-cover. When engaged in laying their 

 eggs at the reddish-brown extremitj" of a pine twig, near the buds, 

 these weevils are undoubtedly protected by their shape and color from 

 the observation of birds, some kinds of which are constantly on the 

 search for such beetles. 



While living in their " mines" or tunnels, the grubs are exposed to 

 manifold dangers from d^ruivorous grubs, particularly the young of 

 beetles of the family Tenebrionidce, etc. We have not detected any Ich- 

 neumon or Chalcid larvae or flies in their burrows, but these are not 

 uncommon in those of the Scolytid bark-borers. At all events these 

 insect enemies keep the larval pine weevils within due limits, otherwise 

 their injurious effects in forests would be more marked. 



The presence of the grub of the white-pine weevil in a branch or 

 twig or under the bark of a young or old tree, maybe atonce known by 

 its peculiar cells. When the grub is full-fed and ready to change to the 



