the wasp parasite. Tiphia parallela (2), which in the hitter ishuid 



tends to hold it in control. To illustrate its abundance in Mauritius 



(where for a while it threatened to paralize the sugar-cane industry). 



in a period of nine months, from August, 1911. to Api-il. 11)12. a 



total of twenty -seven and one-half millions of grubs, pupa', and adults 



(mostly adults) were collected from the sugar-cane fields over an 



area scarcely three miles sciuare surrounding the Botanic Garden (6). 



In the West Indies, aside from Barbados and Porto Rico, cane is 



known to be injured by a species of Phyllophaga in Antigua (26) and 



by grubs of Phyllophaga patnielis in St. Kitts (22). The adults of 



P. patens are said to be very destructive to cacao foliage in St. \'iu- 



cent (19). A bulletin of the American IMuseum (15) lists 24 species 



of Phyllophaga and 2 of Phytahis from the West Indies, V.\ of wliidi 



are credited to Cuba and 4 to Haiti, but none to Porto Rico. 



In British Guiana a beetle known as the "small black hard Inick, '' 

 Dyscinetus hidentatus, which is the adult of a white-grub, is con- 

 sidered a bad enemy of cane, and a related species, Ligyrus chenus, 

 is occasionally injurious (16). Like the Ligyrus rugiceps of Louisi- 

 ana, it is the adult stage in wliich damage is done by tiiese two Ijcctles. 

 .Dyscinetus sometimes attacks young cane shoots in such numbers as 

 to kill them back as fast as they germinate. 



Life-History Work on White-Grubs Done Ei*ewhere. 



Because of their subterranean habits, white-grubs are amonir thr 

 most difficult of insects to rear to maturity and to gain any definite 

 knowledge of their changes, or molts. Outside of Europe, prior to 

 1916, very few species had been reared to maturity and theii- lifr- 

 eycles determined. As late as 1913, a bulletin of the U. S. Depart- 

 ment of Agriculture (4). in discussion of the genus Lachnosirma 

 {Phyllophaga) , stated: "There is only one pul)lished record, involv- 

 ing a single species, in which an individual belonging to this genus 

 has been reared from i^%g to adult." Since that date, however, con- 

 siderable breeding work has been done in Indiana by Mr. J. J. Davis, 

 of the U. S. Bureau of Entomology, to whom credit is due for Imviiiir 

 successfully reared to maturity from the egg eighteen species of the 

 genus, definitely establishing the length of life-cycle of each (5). 



In Australia similar difficulties have confronted investigators in 

 this group of insects. In a bulletin of the Bureau of Kx|»iTiin.'i)l 

 Stations of Queensland published in 1914 (9), it is stated: ".M Hrs* 

 rearing was depended upon to give us evidence of tlie ciitirr period 

 of development, hut we have not as yet succeeded in rejiring ;i simr).- 



51 



