INSECT PESTS OF CIGAR-TYPE TOBACCOS 19 
not for such enemies the infestations in the tobacco fields of this 
area would probably be much greater. 
CONTROL 
CONTROL ON SHADE-GROWN TOBACCO 
The most effective means of controlling hornworms on_shade- 
grown tobacco at the present time is care in keeping the cloth tops, 
side walls, and gateways intact throughout the growing season. If 
a shade structure is situated on land which grew crops other than 
tobacco or tomatoes the preceding season, the chances are very great 
that the soil will contain no hornworm pupae. Under these condi- 
tions there should be no/Anfestation from within. If the walls and 
ditions hornworm moths may deposit eggs on the protruding leaves, and the 
young caterpillars from these eggs work their way downward into the crop. 
top can be kept intact, the tobacco will be free from hornworms 
until the latter part of the harvesting season when the plants reach 
the shade top. When the plants push against the top, moths on the 
outside frequently deposit eggs through the cloth onto the leaves 
which press against it. If the cloth breaks from the continued 
growth of the plants, the stalks push their way outside and are then 
available to the moths for oviposition (fig. 21). The caterpillars 
which hatch from these eggs work their way down into the crop. 
Usually the main portion of the crop has been harvested at this time, 
and the larval feeding is largely confined to the top leaves and the 
suckers. | 
If a tobacco shade structure is situated on land which contains 
hornworm pupae from a previous crop, some infestation will occur 
