MONTHLY NOTES ON GRUBS AND OTHER CANE PESTS. 13: 



abandoned field of volunteer cane. These beetles begin dropping from 

 the feeding trees about 9 p.m., and from that time there is a continuous 

 hum as they come to the lamps. 



From what is said above it is evident that the time to catch both 

 the grey-backs and frencM in light-traps is just at dark, in the region 

 of infestation, before the beetles reach the feeding trees. Few results 

 are obtained by exposing the lights for more than an hour. The value 

 of this treatment is, however, in that the female beetles are destroyed 

 before they can lay their eggs. 



CANE GRUB INVESTIGATION, JANUARY, 1918. 



The flight of the grey-back beetles, though long drawn out, has 

 been comparatively small this year in the region about Meringa Station. A 

 few beetles are still emerging (14th January), and are to be found on 

 the feeding trees, nearly two and a-half months after the first emer- 

 gence in November. We are already finding second-stage grubs of this 

 species in the field, resulting from these earlier emergencies. 



Destruction of Feeding Trees. 



As pointed out in the publications from this Office, the grey-back 

 beetles show a decided preference for feeding upon the foliage of the 

 Moreton Bay Ash. Since these trees are commonly distributed through 

 the forest and often in the vicinity of grub-infested canefields, it would 

 appear to be a profitable procedure to have them all cut out within a 

 circumference of about a mile of such fields. Moreover, these trees, 

 also, appear to be the favourite food plant of both Lepidiota frenchi 

 and L. rothci. In the region immediately around Meringa, all of these 

 beetles appear to travel about half a mile back into the forest, though, 

 no doubt, they would travel double that distance if feeding trees were 

 scarce. There is also the possibility that beetles forced thus far from 

 their breeding ground to feed would not be likely to return to the cane- 

 field to lay their eggs, but would probably place them at the roots of 

 native grasses in the forest, as they did before sugar-cane was intro- 

 duced. 



Trap Trees. 



It might be well to keep a few trap trees about the buildings on 

 each farm, so that the beetles could be shaken off each morning for the 

 fowls. We have found the weeping fig work well for this purpose, for it 

 is usually covered with the beetles every morning. The fowls feed very 

 greedily upon the fresh beetles with no ill effects, though they do not 

 seem to care so much for them when dried and ground up into a meal. 

 Of course, the natural instinct is to break up the insects themselves. 

 The cases reported of poisoning fowls by feeding them collected beetles- 



