THE SUGAR-CANE MOTH BORER. 19 



LIFE HISTORY. 



MOTH. 



EMERGENCE. 



The moth, or adult, emerges from the pupa, which is in a stalk of 

 cane, corn, or other food plant, easily breaking the threads of silk 

 spun by the larva in the tunnel, and forcing its way through the side 

 of the stalk by breaking a thin membrane of plant tissue left by the 

 larva for its ready emergence when it should reach the adult stage. 

 The emergence holes are shown in Plate VI. On emerging the wings 

 are still close to the body, and the moth rests on a convenient leaf or 

 stalk for some time to allow them to expand. 



PROTECTIVE HABITS. 



An adult of the moth borer is very seldom seen, even in the fields of 

 an infested plantation. The moths fly at night and hide among the 

 corn or cane leaves in the daytime, moving only if disturbed. As 

 they are small and of a light-brown color, similar to the dead leaves 

 of cane or corn, they are not readily observed at any time. 



The eggs, which are deposited on the leaves of food plants, blend 

 with the leaves and can be found only with difficulty. The entire 

 pupal period, with most of the larval period, is spent in the burrows 

 formed in the stalks, and in this protected situation the borers are 

 safe from birds and most predacious insects. 



FERTILIZATION. 



The mating of the moths undoubtedly occurs at night, but it has 

 not been observed by the writers. Pairs of moths were placed in 

 small cages made of wire screen and cheesecloth and examined 

 during the evening and at intervals through the night, but the moths 

 were never found in copula. Examinations were begun as early in 

 the evening as 5.40 p. m., 1 and were continued on one night at short 

 intervals until 11.20 p. m., with three more observations at 2.50, 

 3.05, and 5.45 a. m. On another night examinations were made at 

 5.40, 6.40, and 9 p. m., at 11.45 p. m. to 12.30 a. m. (continuously), at 

 1.35 to 1.50 a. m. (continuously), and at 2.15, 3.50, and 7.15 a. m. 



OVTPOSITION. 



In ovipositing the female stands on a leaf with the head upward. 

 She feels about on the leaf with the extended ovipositor and then 

 deposits one egg, pressing it down and flattening it against the leaf 

 with the end of her ovipositor, the egg adhering to the leaf like a 

 tiny fish scale. Then she moves the ovipositor down or to one side, 



'All references to clock time refer to Standard Time. 



