LEPIDIOTA FEEXCHI. 51 



Yet the length of the egg stage was greater than that of L. alhohirtion 

 nnder precisely the same conditions. 



Development of Larvev. — Since this species has a two-year life-cycle 

 the grubs develop more slowly than those of L. alhohirtnm. During the 

 feeding period of the first season — December to May — they pass through 

 the first two stages, doing only slight damage, even where they are 

 located in fields of sugar-cane. In the latter month, or before, they 

 burrow downward and hibernate during the cool weather in resting- 

 cells, 2 or 3 feet beneath the surface. As soon as the days begin to be 

 warm in September or October they moult, changing to the third or 

 final stage, and begin to burrow upward. It is at this time that they do 

 their worst damage to the roots of cane. They continue active for a 

 period of six or eight months, stunting the growth of the cane, even 

 where it is not killed out altogether. 



About April or ^Nlay of the second .vear, these large fat grul)s are 

 fully fed and ready to Inirrow downward again, to form their ])upation 

 chambers. A great deal has been done in order to study the hal)its of 

 the grubs at this season. The depth that they descend depends upon 

 the character of the subsoil, just as in the case of the greybacks. In the 

 red volcanic soils at iMeringa, where most of our observations have been 

 made, we have found the pupation chambers at depths varying from 

 8 inches to 2-1 inches, averaging 18-3 inches. The larvte lie in these cells 

 for five or six months, and gradually the walls of the chamber become 

 coated with the discharges from the alimentary canal, so that the surface 

 appears black and smooth when the grub is ready to pupate in Octol)er. 

 Just before pupation takes place the body of the grub is very shrunken, 

 and the skin is full of wrinkles ; the insect appears almost lifeless. 



Pupation. — It has always been past the middle of October before 

 we found any pupa:? in the field. Grubs kept in the insectary, too, 

 pupated about this time. We have only two definite records of the 

 duration of this stage. 



14th Xovember, 1918. a beetle emerged in the laboratory; the pupa, 

 recently formed, had been dug from under lilady grass at a depth of 

 24 inches, on 16tli October. 18th Xovemlier, another beetle emerged in 

 the laboratory; the grub had pupated on 19th October. Hence it would 

 appear that the duration of this stage is approximately one month. The 

 beetles do not escape from the soil, however, often for a considerable 

 period afterwards, since they must Avait for the rains to set in. These 

 usually begin in November or December, l)ut may not occur sometimes 

 until after the middle of January. 



A chart has been prepared along flu- lines of one used by ^Ir. Davis 

 (107), which illustrates graphically all the stages in the life-history of 

 this pest, as has been described above (Plate XV). 



XATUKAL EXEMIES AXD COXTROL MEASURES. 



The numerous natural enemies of L. alhohirtum, dealt with further 

 along in this paper, are equally effective against this species. Then, 

 too. these factors in control have been discussed at considerable length 

 in Bulletin Xo. 13. 



Artificial control, too, must be along similar lines. Yet the fact 

 that most of the devastating work of this species occurs during the early 

 spring and summer necessitates some modification of our methods. 



