56 AUSTRALIAN SUGAR-CANE BEETLES AND THEIR ALLIES. 



(5 mm. in rotJici). In view of tlie close resemblance of adnlt fjrafa to> 

 that of rothei, it would seem perfectly feasible to connect the grvil)s from 

 Gin Gin with the former species. 



]\Ir. Creamer took the grubs from under a stool of cane that thi\v 

 had damaged; and wrote that on the next farm to his, owned by Mr. 

 Laurisen, 6 acres of plant cane and 3 acres of second ratoons had to l)e 

 ploughed out on account of the grubs, and that 2 more acres of plant 

 cane and 5 more of ratoons had been eaten out. 



The cane is damaged by this species about the middle of sunnner, 

 just when L. frcnchi is active; therefore it is very possil:)le that this, 

 insect has a two-year life-cycle. 



LEPIDIOTA ROTHEI BLACKBURN. 



We have not met with this species outside of the area immediatel^• 

 surrounding Gordonvale, but it is said to occur in the Northern Territory. 

 It is a native of the forest, and does not penetrate into the scrub lands. • 

 The grubs are commonly found in fields either newly cleared of forest 

 growth or with a plentiful supply of grass, their presence in clean 

 (•anefields being rare; dark loam or clayey soils are favoured; in the 

 red volcanic soil of Greenhills they do not occur to our knowledge 

 although beetles have been observed on the edge of the estate. 



The Adults in normal seasons emerge in vast numbers; the earliest 

 emergence record is 1st December, 1917 ; in the following years the dates, 

 for this event are 19th December, 1918, 15th January, 1920, and 13th 

 December, 1920; this usually takes place concurrently with that of 

 frenchi. However, in the past season, the last-named insect Avas first 

 seen on 28th November, whereas rotlici was not out until 13th December. 

 Then, too, they did not occur in the immense hordes of former years : 

 the grass areas in the township of Gordonvale have always been a 

 favourite breeding-ground, yet this season not a single beetle was collected 

 in this neighliourhood. They remained in evidence in the vicinity of 

 ]\Ieringa until 20th January, on which date they were last observed. 



In general the habits of adult rothei agree very closely with those 

 of frenchi. Mating takes place immediately on leaving the ground, but 

 whereas frenchi copulates on fences, posts, weeds, &c., rothei invariably 

 chooses the lower leaves of small trees, at heights varying from 4 to 

 20 feet. Repeated observations have proved that the act of copulation 

 endures between one and two minutes ; this is a wide divergence from 

 the habits of all the species of Lepidiota that we have studied. The 

 following note on the subject from our files is of interest : — 



''At 7-03 p.m. the mating of rothei was observed. The female was. 

 sitting on a leaf about 4 feet from the ground, so her activities in detail 

 could be seen. The vagina was protruded so that the cement glands 

 were visible, just as is the ease when eggs are being laid {see ovipositing 

 of L. aUiohirturn). and a small drop of milky liquid Avas forced out. 

 In a moment two males appeared, and one immediately went into cop. : 

 the other then flew away. As soon as union w^as secured the male hnng 

 head downward, ])ut he only remained in this position for about one 

 minute, when he climbed up on to the back of his mate, Avhere he remained 

 for about another minute, then broke loose and flew away. After about 

 a minute the female also departed. 



"This ability to ])reak awa,y easily is evidently due to the character 

 of the genitalia. The penis of the male in this species is very slender 



