CANE SUGAR. 



Orthopterous Pests. The Orthoptera do not include any of the 

 major pests of the cane ; the one of this order that causes most damage is 

 probably the Mole Cricket 9 (Scapteriscus didactylus) in Porto Rico where, 

 besides attacking cane, it is a general plant enemy. The fully developed 

 insect is about 1 inches long. The damage done to cane is by the attacks of 

 the perfect insect in search of food. The greater part of the life of the insect 

 is passed underground feeding on the roots of cane and other plants ; it 

 emerges at night, and then feeds on the crop above ground. Its attacks 

 continue the whole year round. It has been observed to attack plants con- 

 tinuously, and beyond the demands of its appetite. This insect committed 

 great damage in S. Vincent about 1830, and in Porto Rico became a dangerous 

 pest in 1876, after the destruction by a hurricane of its most effective enemy, 

 the blackbird, this forming an interesting illustration of the effect of distur 

 bance of the ' natural balance.' Its damage is greatest in moist sandy soils ; 

 in dry soils it does not thrive, and saturation and extreme dryness are condi- 

 tions inimical to its development. 



Another Mole Cricket (Gryllotalpa africand] in the Hawaiian Islands not 

 only injures the cane directly, but also does considerable damage to the 

 irrigation ditches by means of its tunnels. 



Amongst other pests of this order 'may be mentioned the white ants 

 (Termes taprobanes] of India, which, according to Hadi, attack the cuttings of 

 seed cane and less frequently the young shoots shortly after germination. The 

 insects known as * thrips ' or ' bladder feet,' which are sometimes included 

 in the Orthoptera, are also known as a pest of the cane in Java. 



Acarid Pests. Mites are a form of life frequently found on canes ; 

 the damage done to the cane is, however, in general small. A serious amount 

 of damage was done in Queensland in 1876 by a mite, Tarsonymus bankroftn 10 ; 

 the disease was then known as ' Cane Rust ' ; this mite is also present in Java, 

 where it does a certain amount of damage, and has also been noted in Barbados. 

 Mites may also be considered as beneficial, since Ormerod 11 has observed the 

 parasitization of the eggs of the West Indian Borer by this form of life. 



"Worms. Certain nematode worms have been connected with cane 

 damage, particularly the varieties Heterodera javanica and Tylencus sacchari in 

 Java. They have also been much studied by Cobb, 12 but that they are to be 

 classed as a cane pest is doubtful. 



Control of Cane Pests. The control of cane pests is mainly 

 -divided into two parts their systematic destruction by methods referred to 

 below, and the prevention of their introduction from foreign countries by a 

 strict system of quarantine. The methods q systematic destruction employed 

 vary with the pest, and below are some accounts of the principal systems 

 in use. 



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