FAMILY CERAMBYCIDAE 333 



should be collected. The bark should be removed from these trees at the 

 end of the week, unless it is wished to study the life history of the insects 

 further. 



(5) In the case of severe infestations of the beetles in the forest, a 

 number of trap trees should be felled for the purpose of attracting the 

 beetles to them to lay eggs. By collecting and killing all the beetles 

 present, and barking the trees at the end of the week, a severe check will 

 have been put on the increase of this pest. The bark should be stacked 

 and burnt unless it can be exposed to a hot sun for a few days, which will 

 serve the purpose equally well. 



Ichneumon sp. The Ichneumon grub feeds parasitically on the Hoplo- 

 cerambyx one, killing it. 



Pupal Covering or Cocoon. Smoky grey, papery in texture, 

 Parasitic and elliptical lozenge shape, with vertical sides. 



Predaceous Foes. Length, 27 mm. 



Fly. Shining, elongate, slender. Head 



yellow ; thorax red ; basal part of wings, which are membranous, 

 yellow, apical half black ; tibiae and tarsi black. Length, about 24 mm. 

 Described from a poor specimen taken dead from a cocoon. The 

 figure shows the pupal case of this insect and the fly. 



Life History. The egg or eggs of this fly are laid 

 by the female in the tunnel near or on the Hoplocerambyx 

 larva. On hatching out the young parasitic grub feeds FIG. 220. 



upon the tissues of the beetle-larva either as an internal Ichneumon sp 



. i -11 j parasitic on Hoplo- 



or external parasite. The former is not killed under cerambyx spinl- 



the attack until it has reached its full size and formed its cornis. Cocoon and 

 pupal chamber in the interior of the tree. This is evidenced 

 by the fact that the beetle-larva has strength enough to enclose its pupal 

 chamber with the calcareous covering before it finally dies from exhaustion. 

 The Ichneumon grub then pupates in safety in the closed pupal chamber, 

 first spinning a smoky-grey papery elliptical cocoon with vertical side walls, 

 resembling an elliptical lozenge, as shown in the figure. How the fly gets 

 out of the pupal chamber through the calcareous covering is not apparent. 

 The only specimen taken was found dead in the cocoon. It is quite 

 possible that the only chance of the fly getting out of the tree lies in its 

 grub killing the beetle-larva before it closes in the pupal chamber with 

 the calcareous covering. That more than one Ichneumon grub ferds upon 

 the beetle one is evidenced by the fact that two of the papery cocoons 

 were found side by side in the latter's pupal chamber. Although this fly 

 does not prevent the damage being done to the trees, since it would appear 

 that the larva forms, or nearly forms, its pupal chamber in the tree and 

 therefore is not killed until it has done all the damage it can, the insect 

 is of undoubted value in the forest, since it keeps down the number of 

 future beetles. It is therefore of considerable interest that its life history 



