42 INSECTS AND MAN 



and America they do incalculable damage, and, on account 

 of their extensive geographical range, there still remain 

 districts where the losses they cause may be reckoned in 

 millions of pounds. Take the case of the Philippine Islands 

 as an example : in the latter half of 1912 locusts did damage 

 to the amount of 2,083,000 in the island of Visaya, the 

 northernmost of the group. Their breeding grounds were 

 found to be in the extensive areas of uncultivated land in 

 Mindanao. In these islands the immature locusts are called 

 " lectones," and, as in other parts of the world, they attack 

 practically every green plant in their path, though at times, 

 for some unexplained reason, they will pass potatoes, sugar- 

 cane, tobacco, and beans. When mature these insects give 

 off a characteristic odour, which is more pronounced in the 

 breeding season, and, with a favourable wind, it is often 

 possible to detect a swarm at a distance of five to eight 

 kilometres by scent alone. 



SOME ENEMIES OF COTTON 



Of the various insects that have made themselves 

 notorious by their attacks upon plants of economic import- 

 ance, few have wrought more havoc than the Mexican 

 cotton-boll weevil, Anthonomus grandis (fig. 3). The 

 early history of this insect, which, being a weevil, belongs 

 to the order Coleoptera and the family Curculionidce, is 

 somewhat obscure. It was first described by Boheman, in 

 1843, from specimens received from Vera Cruz ; in 1871 it 

 appeared in Cuba. In 1885 the beetle appeared, in force, 

 in Northern Mexico, and in this year it was associated with 

 cotton for the first time. In 1892, or probably a little 

 earlier (the date of such events is difficult to determine), the 

 weevil invaded the United States, effecting a landing at 

 Brownsville, Texas, and in its first year became known as 

 a serious pest of cotton. In less than three years the out- 

 look had become so serious that the Federal Department of 



