16 BULLETIN 737, U. S. DEPARTMENT OF AGRICULTURE. 
onic larva les with the head at the rough end, and when development 
is complete it eats its way through the shell in this position. Larve 
a 
- = 
Pai ten a 
hatching in glass vials at the laboratory were observed to consume 
the eggshells almost completely when food was not provided. In 
rearing the insects for experimental work the young larve were often 
observed to live without food for periods of from 5 to 10 days. On 
emerging from the egg they are much more active than at other stages 
of growth and are capable of crawling a considerable distance in 
search of suitable food. Their activity at this stage accounts for the 
rather strange infestation of tobacco products, as the extremely 
minute worms readily enter very small openings in the boxes or con- 
tainers. On hatching the larve are semitransparent, gradually as- 
suming a whitish or creamy color as they become more fully grown. 
The food within the alimentary canal, seen through the skin, gives 
them a dark or dirty color, which varies with the amount of food 
present. When feeding on tobacco the fine particles of dust adhering 
to the minute hairs of the larve give them a brownish appearance, 
which is more noticeable in the last instar. The larve appear more 
robust, deeply wrinkled, and grublike as they become more fully 
erown. The young larva lies and crawls extended to full length; 
the older larve usually assume a curved position and are not so active 
as those newly hatched. At all stages of growth they are negatively 
phototropic, and when exposed to light disappear within the food © 
substances as quickly as possible. 
Larve of all ages are capable of crawling for a short distance and — 
often migrate from infested to uninfested material. This habit often 
accounts for the quick appearance of injury in freshly made cigars. 
Partly grown larve have been found on the cigarmakers’ tables and | 
on the pickers’ tables. They easily enter the open ends of the cigars 
that are being handled, and in a very short time their work can be 
noticed in the bundle or box of cigars. In a box of injured cigars — 
examined, the work of a single larva was traced through four cigars. 
Tn another instance, in a box of sliced plug smoking tobacco, a single ~ 
larva had cut a furrow in the tobacco for almost the entire distance 
- 
across the top of the slices between the oiled paper covering and the 
tobacco. 
It has been observed by leaf-tobacco dealers that a crop of Cuban 
tobacco which remains raw and does not cure quickly is apt to be — 
damaged more by the beetle than the same type of tobacco which 
matures and cures properly. . Under laboratory conditions a test was 
made at Richmond, Va., in 1914, with several types of leaf tobacco — 
which confirms observations made in. warehouses and factories. 
Similar quantities of different kinds of tobacco were closely packed | 
in a tight container and several thousand eggs of the beetle scattered 
