236 INSECTS AFFECTING VEGETATION 



A bud moth is found generally throughout the Hawaiian cane fields 

 and at times is quite numerous. 



It is usually not particularly injurious as it customarily feeds 

 on the dead and drying tissues of the leaf -sheaths of sugar cane ; but 

 when very numerous and on particularly soft varieties of cane the 

 caterpillars do considerable eating of the epidermis, and also eat into 

 the buds and destroy them, occasioning a good deal of loss where the 

 cane is desired for cuttings to plant. 



The grasshoppers feed to some extent on the leaves of cane. Two 

 species of beetles which occasionally invade the cane fields from their 

 common food plants and attack the leaves of the sugar cane are Ful- 

 ler's rose beetle. 



Rats Injuring Growing Sugar Cane in Hawaii. The so-called 

 roof-rat in former years w r as very common in the cane fields of Ha- 

 waii and did considerable damage by eating the stalks. This is also 

 the cane-field rat of the island of Jamaica. The species in Hawaii 

 lives now for the most part in trees and the upper stories of dwellings, 

 since it has been driven to a great degree from the cane fields by the 

 introduced mongoose. The introduction of the mongoose was a 

 benefit as regards its destruction to the rats in the cane fields, but the 

 animal is an undesirable acquisition to the fauna of the islands for 

 the reason that in recent years it has included in its dietary the eggs 

 and young of ground nesting birds and domestic fowls. The destruc- 

 tion of the ground-nesting birds is mast regrettable. 



INSECTS AFFECTING THE COTTON PLANT. 



The Cotton Worm, or Cotton Caterpillar. This insect is per- 

 fectly familiar to all cotton growers. The slender, bluish-green cater- 

 pillar with small black spots, and often with black stripes down its 

 back, which loops when it walks and feeds voraciously on both upper 

 and under surfaces of the cotton leaf, is to be found in cotton fields 

 in the Gulf States all through the summer. It is generally not no- 

 ticed in the early part of the season on account of its insignificant 

 numbers. Later, through the ragging of the leaves, it becomes no- 

 ticeable, and in seasons of abundance the plant is entirely defoliated. 

 Farther north the insect makes its appearance at a later date in the 

 season, and there the caterpillars are not the offspring of hibernating 

 moths, but of the moths of the first or second generation, which have 

 developed in more southern cotton fields and have flown north with 

 the prevailing southern winds. Late in the season moths of the 

 fourth or fifth generation fly far to the north, frequently making 

 their appearance in numbers about electric lights in Canada. There 

 is no absolute evidence of any other food plant than cotton, although 

 many entomologists have surmised that the species has a northern 

 food plant. The specimens seen in Canada have, however, in all 

 probability flown north from cotton fields in the Carolinas, and per- 

 haps even farther south. (Fanners' Bui. 47, U. S. D. A.) 



After hatching from the egg, the young larva feeds at first upon 

 the under side of the leaf, devouring simply the lower parenchyma 

 and not piercing through to the upper side until after the first molt. 

 At first the larva is pale yellow in color, soon becoming greenish. The 



