THE PESTS AND DISEASES OF THE CANE 141 



Classified according to mode of attack, the major pests may be distinguished 

 as : 



1. " Borers," or the larvae of certain lepidoptera and coleoptera, 

 which bore tunnels into and destroy the stalk. 



2. Root-eating larvae (grubs) of many coleoptera, which pass their 

 larval existence in the soil. 



3. Leaf-eating larvae of numerous lepidoptera. 



4. Leaf and stem puncturing insects belonging to the hemiptera. 



Lepidopterous Borers. The moth borers have been associated with the 

 sugar cane almost from the time that its growth became an organized 

 industry. The earliest description is due to Hamilton 8 (1734). They were 

 established as a pest in Guadeloupe in 1758, and are described by Beckford* 

 and Peterkin 3 in 1790. In systematic entomology the earliest descriptions 

 are those of Fabricius 10 (1789), who described the West Indian borer as 

 Phalczna and of Guilding 11 (1829), who made the genus Diatrcea. Of the 

 pests catalogued below, Nonagria and Sesamia are Npctuids, Grapholitha is a 

 Tortricid, Diatrcea, Chilo, Polyocha, Scirpophaga, and Anerastia are Pyralids. 

 All these are very closely related genera. Castnia licus is, however, a Castnid 

 and has little affinity to the other genera ; the moths in this genus possess 

 clubbed antennae and thus form a link between the Rhaplocera (moths) 

 and the Heterocera (butterflies). 



The borers that have been observed are catalogued below : 



TOP BORERS. Scirpophaga auriflua. The white borer of India. 



Sc. monostigma. The black-spotted borer of India. 



Sc. intacta. The white borer of Java. 



Sc. chrysorrhtza. India. 



Chilo infuscatellus. The yellow borer of Java. 



Grapholitha schistaceana. The grey borer of Java. 

 STEM BORERS. Diatrcea saccharalis. The West Indian borer. 



D. canella. Demerara. 



D. incohati. Demerara. 



D. striatalis. The grey stem borer of the East Indies and Australia. 



Chilo auricilia. The gold-fringed borer of India. 



C. simplex. India. 



Nonagria uniformis. The pink borer of India. 



Anerastia albutella. The green borer of India. 



Sesamia nonagrioides. The purple borer of Java, East Indies, Madeira, Maur- 

 itius, Spain, North Africa, Madagascar. 



Castnia licus. The large or giant borer of tropical America. 

 ROOT BORER. Polyocha saccharella. India. 



As will be seen from the above list, the borers have a very wide distri- 

 bution, the only considerable district free from them being the Hawaiian 

 Islands. 



All the borers have a very similar mode of attack. The female oviposits 

 on the leaf whence the caterpillar on emergence penetrates the cane usually 

 near an eye (stem borer) or near the vegetative point (top borer). In the 

 latter case the shoot is killed, but in the former the damage is confined to 

 destruction of sugar, to impure juices, and to liability to fungus attacks, 

 particularly of red rot (Colletotrichum falcatum) as a wound parasite. Figs. 

 43 and 44 illustrate the different modes of attack of the stem and top borers. 



The large or giant borer or cane sucker, Castnia licus, has different habits. 

 The eggs are laid near the ground and the caterpillar penetrates the lower 

 portion of the stem and also the underground system of the cane. The 

 larva and moth of Diatrcea striatalis and of Sesamia nonagrioides are shown 

 in Plate XVI, Nos. i and 2, 3 and 4. 



