Notes on Insects Damaging Sugar Cane in Queensland. 3S 



Section E. — Insects Devouring the Roots. 



Under the above heading are placed the various kinds of root-eating 

 Scarabaeida^ known to attack sugar-cane at Gordonvale, including our 

 worst offender in this respect, the notorious Grey-backed or Mealy-backed 

 Cockchafer, that is justly regarded as a standing menace to the prosperity 

 •of a great industry. This section may be conveniently subdivided into 

 two classes, comprising (1) beetles known to be eminently destructive or 

 likely to become serious pests; and (2) species of little or no present 

 economic importance. 



Class I. — Notably Injurious Species. 



(40) " Mealy-backed Cockchafer " (Lepidiota alhohirta, Waterh.). 



(41) Cockchafer Beetle (Lepidiota frenchi, Blackb.). 



(42) Cockchafer Beetle (Lepidiota rothei, Blackb.). 



(43) Cockchafer Beetle (Lepidiota caudata, Blackb.). 



(44) Cockchafer Beetle (Lepidiota sp. No. 683). 



(45) Cockchafer Beetle (Lepidiota sp. No. 215). 



(46) Dynastid Beetle (Dasygnathus australis-dejeani, Macl.). 



(47) " Christmas Beetle " (Anoplofinathus boisduvali, Boisd.). 



(48) Rutelid Beetle (Anomala australasiae, Blackb.). 



(40) LEPIDIOTA ALBOHIRTA, Waterh. (Family MELOLONTHIDAE). 

 Plate IV., Fig. 40, p. 34. 



Description of Beetle. 



Deep brown, thickly covered, except on legs and central area of 

 abdominal segments, with minute white sharply pointed pear-shaped 

 scales, not placed in punctures but lying on the surface of the elytra 

 aud readily detachable. Freshly emerged specimens are uniformly gray 

 and mealy-looking, but after a few days become more or less rubbed, the 

 portions of denuded surface showing as irregular brown blotches. Head, 

 anterior edge, and venter of prothorax, coxae, and legs sparingly fur- 

 nished with dull yellow hairs. Antennal club of male 6-jointed ; of 

 female 5-jointed. 



Natural Insect Enemies. — (1) '' Digger Wasp " {Dieles formosus, 

 Guerin) ; (2) " Digger Wasp " {Campsomeris radula, Fab.) ; (3) 

 " Digger Wasp " {Discolia sorrjr, Smith) ; (4) Parasitic Hy {Tachinidce 

 sp.) ; (5) Parasitic fly (Muscidm sp.) attacking the adult beetle; (6) 

 Predaceous larvas of an Elaterid beetle {Agryprus mastersi). 



NOTES ON METHODS OF REPRESSION. 



The following notes summarise various phases of experimental work 

 relating to the control of this insect published from time to time in 

 progress reports. 



Light Traps. 



As a result of research conducted during November and December, 

 1914, it was found that both sexes are readily attracted to acetylene light 



