22 The Cane Grubs of Australia. 



Stage III. was found on December 26th, and in January 43 per cent, 

 were in this Stage; larv^je were found in cells as early as May 31st, and 

 had all pupated by the beginning of September, the few that were taken 

 ,siil)se(iuently invariably proving to be parasitized. 



The duration of the life cycle has not been definitely decided, but is 

 probably one year, since no Stage II. larvae were obtained after March; 

 if this lu'pothesis is true, it is hardly accountable that larvae could have 

 reached Stage III. hy December 26th ; on the other hand Stage III. of 

 Cacachroa decorticata, which emerges se"STral weeks after this species, 

 have been recorded as early as Februarj^ 1st. 



Collecting by following ploughs in the past sixteen months has 

 yielded larvie as follows: — September 3, October 5, November 1, 

 December 8, January 182, February 197, March 213, April 156, May 122, 

 June 23, August-December ; or 910 larva? out of a total of 7,678, that is 

 11-85 per cent, falling third in the list. In canefield collections it is 

 third, in forest and f alloAv lands fifth ; in volcanic soil collections it is 

 seventh, and in dark and clay loams third. In the dark loam soils it is 

 plentiful, only a small percentage of the total coming from volcanic soils. 

 The larvip are also frequently found in alluvial sandy loam rubbish- 

 heaps. 



The Pupa. 



In 1914 the first pupa was obtained on August 29th; in 1915 they 

 were plentiful in our breeding cages by August 16th ; thus the species is 

 the earliest to pupate. An exceptional record is of a pupa found on 

 May 20th. 



The Adult. 



The earliest adult emerged from the pupa on September 14th, 1914 ; 

 in 1915 they emerged by the end of August. Beetles have occurred in 

 canefields, following ploughs on the following dates: — September 24th, 

 October 2;7th, November 2nd, 4th, 11th, 19th, 26th, December 6th ; these 

 were no doubt emerged specimens that had re-entered the soil to hide. 



On November 18th and 29th numbers were noticed flying in a cane- 

 field at dusk, red volcanic soil ; several caught all proved to be females. 



PENTODON AUSTRALIS Blackburn. 

 An adult caught at light, Gordonvale, 3rd January. 



CHEIROPLATYS Sp. C. 123. 

 A single adult captured at light, 14th December, Harvej^'s Creek. 



SEMANOPTERUS DEPRESSIUSCULUS Mad. 



The Larva. 



All the larvoi from Gordonvale were collected in alluvial sandy 

 loam rubbish-heaps. At Babinda, on 21st September, 1914, ploughing 

 in a clay loam jungle canefield produced 2 Stage III., and again at 

 Harvey's Creek ploughing in a similar situation yielded 2 Stage III. 

 Since all those found in the last six months of the season were in 

 Stage III., it would seem that the species has a one-year life cycle. 



