6± AUSTEALIAN SUGAE-CANE BEETLES AND THEIR ALLIES. 



while the blue giini is restricted to certain localities: l)iit l)oth ar(3 

 invariably attacked. The three other trees seldom suffer depredations, 

 and then apparently only M^hen the foliage is very young. 



Oviposition. — On 17th January, 1919, Mr. Giranlt, ^vhile following 

 the plough in a headland at Grecnhills, found 9 eggs, at a depth of 

 5 inches, and scattered by the plongli ; these hatched on 21st January, 

 and were identitied as this species. While digging a trench in a field at 

 Greenhills on 5th January, 1921, we collected 53 eggs, loose in the soil, 

 with no sign of an egg-chamber or even nodules around each egg; they 

 were scattered in the soil in an area of about 4 inches, 2-6 inches below 

 the surface. In comparison with the eggs of Lepidoderma alboliirtum, 

 they were very white, even bluish white, and were quite spherical in 

 form. 



There is very little doul)t that the females are able to deposit a 

 •comparatively large number of eggs. One, captured as she was about 

 to enter the grass on the morning of 13th January, was dissected and 

 found to contain a set of 32 fully developed eggs. On 18th January, 

 1921, several weeks after the adults first emerged, a female collected 

 from a feeding-tree had 50 eggs ready to lay, and it is very probable 

 that this was not a first set. These beetles have eight egg-tubes in either 

 ovary, each tube containing 3 or 4 eggs ; thus it would be possible to 

 deposit 64 eggs at once. ]Mr. Jarvis confined a number of adults, and 

 obtained the following sets of eggs from separate females : 36, 34, 57, 

 63, 48, 39, 56, 29, 35. 



The Gruh. — The grubs occur in varied situations; they are abundant 

 enough in the volcanic soil of Greenhills, which contains very little 

 humus; black and forest loam soils are equally attractive; but they 

 Avould appear to have a particular penchant for piles of trash, decaying 

 rub])ish in general, and even half -sandy vegetable-refuse heaps. Although 

 prolific enough, we have not yet had an instance brought to our notice 

 of definite damage to sugar-cane caused by these grubs. In neglected 

 fields of cane and grass at Greenhills they were especially plentiful on 

 8th February, 1921. 



Girault and Docld stated "that it is ol)vious that the species has a 

 life-cycle of more than one year"; they gave the periods for the three 

 stages as 22nd November to 18th April for stage 1, 16th March to 6th 

 November for stage II, and throughout the year for stage III. Later. 

 Dodd remarked that stage III larva^ found in November and December 

 had recently moulted from stage II. 



Subsequent investigation has supplied most puzzling data, most of 

 which go to support former observations, but a few are in direct 

 opposition. Herewith we summarise some of the supporting evidence. 

 On 2nd December, 1920, the plough at Greenhills unearthed three 

 stage III grubs that had recently moulted from stage II, in fact the 

 cast skin of one was ploughed out with the grub ; stage III grubs were 

 also found on 5th January (surely too early for a first-year develop- 

 ment?). In 1918, Mr. Girault noted the stages of all of the grubs that 

 he collected by following the plough, with the following results for each 

 month: — February, 1 stage I, 68 stage II, 121 stage III; March, 42 

 stage II, 87 stage III; April, 103 stage II, 329 stage III; May, 68 

 stage II, 185 stage III ; June, 20 stage II, 65 stage III ; July, 2 stage II, 

 1 stage III. It will at once be noted that the ratio of the two stages 

 does not radically change in a period of several months; now if the 

 .species had a, one-year life-cycle it might reasonabh^ be supposed that 



