18 MONTHLY NOTES ON GRUBS AND OTHER CANE PESTS. 



emerging from the cocoon the female continues its useful work, it appears 

 highly probable that at least four, if not more, generations may occur 

 annually. We assume such activity to be possible on account of the 

 insect in question being parasitic upon five species of scarabaeid cane 

 grubs, two of which frequent the soil for periods of from five to six 

 months, while the others, including Lepidiota frenchi, pass at least a 

 year in the larval stage. It follows, therefore, that this parasite need 

 never be at a loss for a suitable host on which to oviposit. 



"Adverse climatic conditions, such as excessive wet or low tempera- 

 tures, would, however, doubtless operate at times as natural checks to 

 its increase. 



"Whilst dealing with this subject we may mention, as an interesting 

 fact, that our breeding experiments this month have demonstrated that 

 unfertilised females of the digger-wasp, Campsomeris radula, will com- 

 mence oviposition four days subsequent to emergence from the cocoon, 

 and that such unfertilised ova hatch in a normal manner and produce 

 wasps of both sexes. 



Additional Cane Beetles. 

 "About the beginning of January, specimens of a beetle, together 

 with various grubs obtained from cauefields in the Gin Gin district, 

 were sent to this Office by Mr. H. T. Easterby for identification. The 

 beetles, which happened to be new to our collection, proved to be a 

 cockchafer closely related to root-eating scarabajidfe affecting cane, 

 while the grubs included three kinds, the largest form being a species 

 of Lepidiota not occurring in the Cairns district, and the remainder 

 representing the genera Isodon and Haplonyclia. 



A New Cane Pest. 



"A species of bag-moth (Family Psychidae), not hitherto recorded 

 as being injurious to cane, is sometimes noticed in plantations around 

 Gordonvale, where it occasions minor damage to the leaf-blade resembling 

 that due to grasshopper injury. 



"The caterpillar of this species constructs as a protection a tough 

 •elongate bag of silk, covering it at first with minute woody fragments, 

 and finally, when about an inch and a-half long, adding a number of 

 slender sticks of varying length, which being attached at one end project 

 on all sides from the surface at acute angles, near the mouth-end of 

 the bag. Specimens of these curious case-moths are being bred at the 

 Insectary in order that the species may be identified." 



CANE GRUB INVESTIGATION, MARCTT, 1918. 



The hurricane which passed through the Cairns district on the 

 evening of 10th March upset things generally at IMeringa. Most 



