15 



18 centimeters. When this metliod of feeding is resorted to, the greatest 

 damage results, as the rain generall,y fills up the hole, and unless the 

 plant is very vigorous the stalk rots and dies. The second brood of 

 caterpillars often operate on the blossoms and seed pods of the plants. 

 Wlien feeding on the blossoms the corolla alone is generally eaten. 

 The seed bolls are attacked shortly after the young seeds are formed and 

 while they are still soft, a hole is gnawed into the side of the seed pod 

 and the placenta, on which the seeds are borne, and many of the seeds 

 are destroyed; then tlie caterpillar withdraws and continues operations 

 on another pod. 



Individuals of this species do not confine their attention to tobacco 

 alone, but also feed on tomatoes, corn, and cotton. As the tobacco crop 

 of the Cagayan Valley is followed by one of corn, the conditions are 

 ideal for the propagation of this species. ^^Qlen operating on corn, the 

 eggs are laid on the silk of the yoimg ears and the worm eats its way 

 inward, feeding upon the kernels of the ear. 



Different methods of controlling this species have been tried. Arsenate 

 of lead sprayed in a solution of 1 kilo of arsenate of lead to 150 liters of 

 water killed the insects within 48 hours. Paris green mixed with lime 

 at the rate of 1 kilo of Paris green to 20 kilos of lime, and blown on the 

 plants from a hand bellows also proved very efficient. We would recom- 

 mend that the hand bellows be used. This apparatus is easily handled, 

 requires no water and can be operated by one man. It can be taken up 

 or laid down at pleasure, and it costs but little. Experience with insecti- 

 cides in these Islands, however, indicates that the time is not yet at 

 hand for the use of poisons l)y the majority of the Filipino planters, as 

 they seem to forget that a poison is just as dangerous to live stock as 

 it is to the pest. 



Since the worms pupate in the ground about 7.5 centimeters below 

 the surface, gi-eat nmnbers of the pupae may be destroyed by plowing 

 the ground, as this will expose them to the sun, which if strong will 

 kill them. The mature moths are of a light tan color with buff-colored 

 underwings and a dark spot on the lower margin of each wing. These 

 moths may ])e destroyed by placing lanterns in the field at night with 

 pans of water underneath. The moths are attracted to the light and 

 fall into the water where they will drown. 



Among other leaf feeders that attack the tobacco plant is a large 

 dark-gray caterpillar with white and black markings on the back. These 

 caterpillars feed mainly at night and seek the shade during the day. The 

 best method of combating them in this country is to keep them picked 

 off by hand and to destroy them by cultivation. As these caterpillars, 

 like those of the preceding species, pupate underground they may be 

 killed by being turned up and exposed to the sim and rains. 



Another insect responsible for considerable damage is the larvae of 

 a small Pyralid moth. The eggs of this moth are laid either on the 



