48 AUSTEALTAN SUGAR-CANE BEETLES AND THEIR ALLIES. 



produce more eggs before succumbing. Only eight of these thirty-eight 

 specimens contained ripe eggs; the remaining nine -had ova in various 

 stages of development. 



27th December, I dissected the females of forty-seven pairs taken 

 in cop. on cane-leaves, and found that forty-two of them had laid, 

 though fifteen of this number had begun to form new sets. The 

 remaining five had ripe eggs, in the following numbers: 22, 31, 35, 35. 34, 

 an average of 314 eggs each. 



5th January, 1921, the beetles continued in tremendous numbers, 

 so that the mating pairs covered the posts and wires of the fence. I 

 dissected seventy females taken in cop. They had all evidently laid; 

 but fifteen of them were almost ready to lay again; of the balance, 

 thirt3''-five had new sets well started, and twenty had evidently laid a 

 second time, for their ovaries were practically empty. 



29th January, mating still continued as usual, the pairs hanging 

 thickly in low bushes, but the numbers were considerably reduced, so 

 that they Avere not found on the fences. Twenty mating females were 

 dissectecl, and I found ten of them with nearly empty egg-tubes, showing 

 that they had recently laid; five had sets started with about one egg 

 in each tube, half-size ; the other five had eggs ready to lay again as 

 follows : 15, 5, 15, 14, 15. 



With this information we knew definitely that the beetles continued 

 to mate and produce eggs as long as they lived. As to the number of 

 eggs laid we can only conjecture, since they do not act naturally in 

 confinement. Yet it is safe to assume that several sets are produced, 

 for the beetles are usually on the wing for two months or more. 



]\Iany beetles were placed in cages with soil during the period of 

 their abundance, in an attempt to study their laying habits. In some 

 case.s they were supplied with fresh leaves of jMoreton Bay ash or 

 bloodwood daily, and in others kept without food. Interesting observa- 

 tions were also made by keeping the beetles enclosed in soil, so that 

 they could neither come to the light nor feed. 



4th December, 1920, many pairs of beetles taken in cop. were 

 confined in cages containing soil, with light above ; half of these were 

 fed and the others starved. 



11th December, the cages had been cared for daily; the beetles 

 were always found beneath the soil, and, in the case of those with food, 

 slight evidence of eating was obtained. On this date one of the beetles. 

 No. 4, without food, had de})o.sited four eggs, loosely and singly in the 

 soil. 



15th December, this same beetle (No. 4) deposited fourteen more 

 eggs ; they were placed singly as before, each apparently in a small 

 walled chamber. One of the beetles supplied with food, No. 1, laid 

 two eggs. 



18th December, the beetle in cage No. 1 had laid two more eggs. 

 Another of the starved beetles (Xo. 3) laid twenty-three eggs, loosely 

 and singly in the soil as above. 



20th December, beetle in cage No. 3 laid another egg, and No. 4 

 had laid five more eggs. 



23rd December, beetle in cage No. 1 laid eleven more eggs. Beetles 

 dead in cage No. 3 ; total eggs twenty-four. In cages Nos. 7 and 8, 

 without food, beetles dead, with no eggs. 



After seventeen to twenty days the beetles without food died ; those 



