140 CHAPTER IX 



in Florida. In special connection with the cane sugar industry may be 

 mentioned a woody shrub, Lantana camara, known as Lantana in Hawaii, 

 and as " vielle fille " in Mauritius. This was brought as an ornamental 

 plant to Hawaii and rapidly became a serious pest, taking over pastures 

 and abandoned or fallowing cane fields. This plant is an inhabitant of 

 Mexico and the West Indies. Koebele,^ knowing of its presence there, 

 but not as a pest, was led to investigate the cause. He found that it was 

 controlled b5'' a fly, Agromyza sp, which oviposited in the seed, and by two 

 moths, Platypstilia rusellidactyla and Crocidosema lantana, which attacked 

 the flower heads. The introduction of these insects into Hawaii resulted 

 in a very short time in the almost complete disappearance of the weed. 



A similar introduction into Cuba of an ornamental plant, Dichrostachys 

 nutans, of habitat Northern Africa, has resulted in the covering of many 

 acres of pasture land with dense thickets. In Cuba this plant is known as 

 " aroma." It is an acacia-like shrub, with showy violet and yellow flowers. 



The eradication of weeds should not, however, be confined to the fields 

 alone, but should extend to the roads and vicinity of the fields, since such 

 places may act as foci of infection whence seeds may be continually carried 

 by natural agencies to the cultivation. In addition, as pointed out at 

 greater length elsewhere in this chapter, such weeds may serve as breeding 

 places for obnoxious insects, and as host- plants for fungi that also attack 

 the cane. In certain British Colonies the destruction of weeds on road-sides 

 has been made compulsory on the owners of lands abutting thereon. The 

 usual method of destruction of weeds is by the use of the plough or by the 

 hoe and cutlass, and forms a part of the regular routine of any farming 

 ndustry. The use of plant poisons has been experimented with for many 

 years past, and considerable interest has attached to the use of sodium 

 arsenate as developed by Eckart at the Olaa plantation in the Hawaiian 

 Islands. (C/. Chapter VIII.) 



Mammalian Pests. — The most important mammalian pest of the cane 

 is the rat ; it is of cosmopolitan distribution and was observed as a 

 cane enemy by Captain Cook in the eighteenth century in even so isolated 

 a part of the world as the Island of Tanna.' At times, in British Guiana 

 for example, rats appear in enormous numbers, and not only destroy cane, 

 but also do damage to dams and parapets. Hares are known as a cane pest 

 in Mauritius, where they do no inconsiderable damage. Elephants, 

 bears, jackals and wild pigs must be regarded as cane pests in India. It 

 is not perhaps altogether wrong to include the labouring population as an 

 occasional enemy. This is particularly true in Cuba, where incendiary 

 fires are of frequent occurrence. These fires are often set so as to force 

 the administration to raise the price of cane cutting in order to harvest the 

 burnt areas before the cane has quite spoiled. 



Insect Pests. — The cane, in common with other crops, is attacked by 

 a large number of insects. The majority of these pests attack the cane 

 in common with other plants in search of food, but some have become almost 

 specialized in their habits in regard to the cane. As regards their systematic 

 position, the most serious pests are included in the lepidoptera (moths and 

 butterflies), the coleoptera (beetles) and the rhyncota or hemiptera (bugs in 

 its technical sense). The damage is done by the larvae of the first two classes, 

 the perfect insect being the destructive agent in the case of the third class. 



