38 THE SUGAR-CANE INSECTS OF HAWAII. 












Fic. 5.—Work of the Hawaiian sugar- 
cane borer in sugar cane: a, a, a, Emer- 
gence holes made by the larva before 
pupation; b, b, ‘‘rupture’’ holes, ap- 
parently accidental and made by the 
larva while feeding; c, holes made by 
the female borer for the reception of 
her eggs; d, cocoon; e, larva; f, f, 
“‘frass’? or undigested cane fiber, 
passed by the larva. One-half natural 
size. (After Terry.) 
depends to a great extent upon the con- 
dition of the food plant and climatic 
conditions; that is, the development will 
be more rapid in softer cane and during 
the warm summer months than during the 
low temperatures of winter. 
When ready to pupate—that is, to trans- 
form to the inactive stage preparatory to 
emerging from the stalk as an adult 
beetle—the larva (fig. 5, a) forms about 
itself a cocoon (fig. 5, 6) from the fiber of 
the stalk within the tunnels it has made 
in feeding. The adult beetle on issuing 
from this cocoon bores its way through 
the side of the stalk to the exterior, and 
this opening in the lower joints of the cane 
is the first distinct symptom of the pres- 
ence of the borer. The length of the 
pupal period is as variable as that of the 
larval, the average time for transforma- 
tion and emergence being from two to 
three weeks. 
The beetles are night flying and hide 
during the day down within the sheaths 
of the lower leaves. The softer varieties 
of cane are more subject to attack than 
the hardier varieties, and the borer is more 
abundant in the wet districts than in the 
dry. Cane which has received an abun- 
dant supply of water by irrigation suffers 
more from the work of the borer than un- 
irrigated cane. The borers occur in the 
largest numbers in young cane and the 
suckers are infested to a much greater 
degree than the stalks. The borers always 
occur in the largest numbers in the vicinity 
of the track used to haul cane to the fac- 
‘tory, issuing from infested stalks that have 
dropped from the cars and have not been 
collected and destroyed afterwards. 
The borer is a strong flyer and spreads 
from field to field in thismanner. Itisdis- 
tributed in infested seed cane and also 
develops from the stalks left in the field 
after harvest or dropped from the wagons 
or cars in hauling to the factory. 
