THE DISEASES OF THE SUGAR-CANE. 463 



upon it. Pits were accordingly dug at intervals in the 

 cane-fields, and a fire made in each. The flames were 

 quickly smothered, the place of each being marked by a 

 heap of dead ants the size of a mole-hill. These direct 

 attacks appear to have been entirely unsuccessful, and the 

 ants only disappeared after a hurricane in 1780.^ 



A distinct advance is to be noted in the advice given by 

 S. Martin Senr., about the same time, with regard to the 

 "blast," probably an aphis, attacking the canes in Antigua. 

 He recommended the use of "wooling raggs dipped in soap- 

 suds after having been used in washing cloaths " — an early 

 reference to the spraying of plants so widely adopted at the 

 present day.^ 



3. The remedies applied during more recent years have 

 usually borne directly upon the natural habits of the past. 

 A careful study has now been made of the life-history of 

 many of the parasites, in order to select the stage in which 

 the application of insecticides and germicides would be most 

 successful. This varies considerably in different cases. The 

 grub appears to be the point of attack in the moth-borer, 

 the freshly hatched young in the scale-insect, the egg-cases 

 in locusts, and the adult beetle in the Java pest, Apogonia 

 destructor. Although the life-history of the latter has not 

 apparently been determined beyond dispute, it has been 

 very carefully studied by Kobus,^ Zehntner,* and other 

 zoologists, and may serve us as an example. 



There are usually two main flights of mature beetles, 

 one in November and one in March. The larvae attack 

 the cane roots between these dates, the injury first becoming 

 noticeable in January. The larger, November, flight is 

 determined by and closely follows the west monsoon, which 

 also brings the first rains. Beetles collected during the last 

 days of October have very immature generative organs and 

 no food in their alimentary canals. They feed at night upon 

 various leguminous plants i^Sesbama, Arachis, Soja, Taiua- 

 riiidtis) and push themselves under the loose earth at sun- 

 rise. Specimens dissected in the early days of November 

 frequently have well-filled digestive organs, and, later in 

 ^ Schomburgk. -Martin ^Kobus(i). •* Zehntner. 



