IVAK IRAC.ARDH. 



of lune. In tlie middle of August singly attacked needles were noticed and 

 låter in the season the rharacteristic bundles of excavated needles (fig. 6) 

 occurred, in 1914 inhabited by the larvae as late as the zoth of October, 

 single larvae being found even as late as Noveml)er loth. '!"he needles attacked 

 do not change colour niuch during the autumn, the damage being, as a con- 

 se<iuence, at this time rather inconspicuous. The larva is very easily disting- 

 uished by the two light red j)aradorsal bands (fig. 8 c and d), the colour of 

 which is due to the small semispherical cuticular processes being red. The 

 ground colour of the larva is light green vvith the prothoracic and anal shield 

 and the thoracic feet brown. All the hairs are surrounded by dark spöts (fig. 

 S a and b). Structural details of the larva are given in figs 7, 8 and 9. 



Grapholitha nanaua Tr. Needles mined by this larva were noticed the 21st 

 of May near Stockholm, as a rule only 2 — 6 needles being attacked. Baer, 

 who describes an attack in (lermany, is of opinion that the larva in the autumn 

 only excavates one needle, where it hibernates, and on May 5th the larvae 

 had generally excavated only five needles, rarely 6 — -8. In the instance 

 where in Sweden as late as May 21st only two needles had been attacked it 

 is therefore probable that the moth had hibernated in the egg-stage. The first 

 moths emerged on June i6th. It was not possible to find any difference 

 between the mode of feeding of G. tedella and G. natiana. The latter how- 

 ever, is far morc dangerous on account of the time of attack, the spring. 

 In 19 1 3 this species did great injury in the vicinity of Kvesjön in Norway 

 and at Frostviken in Sweden, many spruce-trees being quite defoliated, the 

 young shoots, however, developing normally. 



The larva is a ])ale dirtyish yellow and 8 mm. long, the head capsule is 

 black; the i)rothoracic shield dark-brown, and the anal shield the same colour 

 as the body. The hairs of the body are not surrounded by dark spöts as in 

 tedella, a very conspicuous difference. Details of the larva are given in fig. 11. 

 Argyresthia illuminalella Zell. Buds damaged by this moth were ob- 

 served at the Kxperimental Field on May 2 5th, the buds being quite exca- 

 vated and the needles in the distal part of the axis having fallen ofif (fig. 

 13 a). Both the terminal and the lateral buds were partly filled with excre- 

 ment, and in the terminal bud the pupa was found with its head turned 

 towards the basis of the shoot (fig. 13 b). The moth emerged on the 14 — 

 2 7th of ]une. Ratzehurc; emphasizes the fact that only the buds are destroyed, 

 but no part of the axis. This seems, however, to be the rule when the attack 

 occurs on the lower branches of old trees, and an examination of a nuniber ot 

 shoots attacked reveals the fact that the bigger the buds are the smaller is the 

 part of the axis that is destroyed, which seems to prove that the larva attacks the 

 buds first and then the axis to the extent necessary, the length of the part ot the 

 axis destroyed varying between 8 and 20 mm. On the terminal buds ot 

 younger trees, on the other hand, the injury corresj)onds in all respects to 

 that described by Ratzkiukc. In fig. 14 a such a bud in longitudinal section 

 is delineated: we notice the sjjirally-twisted gallery in the bast which leads to 

 the terminal bud (fig. 14 a and ,i,' fig. 14 h). On the ventral side of the axis 

 we notice a circular hole (fig. 13 <"), situated at the end of the excavated 

 ]>ortion; this feature greatly puzzled Saxkskx, who advanced the theory that 

 it was caused by the larva of a weevil. My own observations go to prove 

 that the hole is actually made by the larva after having finished feeding, 



