Florida Agricultural Experiment Station


to distinguish them from the more recently introduced Colo-
rado potato-beetles." They are known in parts of Florida as
"Yankee bugs," perhaps from the bluish color of certain species.
The adult beetle crushed against the skin causes a blister, hence
the name blister-beetle." It is also called Spanish fly," cer-
tain species being the source of the drug of that name.
 Eight species of blister-beetles are more or less trouble-
some to vegetation in Florida. The most common one is the
gray blister-beetle (Epicauta heterodera) which has no stripes.
The striped blister-beetle (E. vittata) (fig. 61) is frequently
seen.
 The work of all the species is about the same except that
each shows a preference for different plants. They strip all
 the softer parts of the leaves, leaving only the mid-
 ribs. The beetles usually feed in colonies, some-
 times so large that they quickly strip and ruin a
 patch or an entire field.
 If the colony is small the quickest way to
 exterminate it is to collect the beetles in a pan of
 \ kerosene. They are quick to take alarm and the
F GG 61.- collector must work rapidly. If the colony is large
 blister- the plants should be sprayed with lead arsenate.
 Natural The larvae feed on the eggs of grasshoppers and
 size. (From
 U. s. Bur. are beneficial to agriculture. For this reason it
 of Ent.)
 is better, wherever possible, to drive the beetles
from the field rather than to poison them. To do this, use
a bundle of twigs with which to whip the plants and work
with the wind, driving the beetles quite a distance from the
field to prevent their quick return. It may be necessary to
repeat this driving frequently.
 BEET LEAF-MINER (Pegomyia vicina)
 This insect belongs to a large class made up of small pests
which often escape the notice of the trucker because of the
small size of the insect and the wound inflicted, while the un-
thrifty condition of the injured plants is laid to a lack of fer-
tilizer or water. Collectively they inflict severe damage.
 This maggot-like larva of a two-winged fly frequently
burrows in the tissue of beet leaves. If they become numerous
they will materially check the growth of the plants.
 In its protected position, the grub cannot be reached by
any insecticide, but the grower can check an outbreak by de-
stroying all infested leaves. This at least should be done when