The Atlanta constitution., 1900-04-09
STRIPED CUCUMBER BEET
Diabrotica Vittata, Fabr.

/ DTS IN the spring. ftdruly ntiNt inc SeSN-
lings pushed through the soil before these
small yellow and black striped beetles
begin feeding on the leaves and succu-
! lent stems So abundant and ravcnous
are they during certain years. that most
of the plants in large fields may be quite
destroyed.
THE INSECT DESCRIBED.
Egg-The eggs are quite small.
measuring on an average SO mill
limeters long by AS millmeters wide. AS
seen with the naked eye, they appear 10
be nearly round, and when first deposit
| ed are of n very light yellow color. I'm
der the microscope some variation in
shape is noticed. and fine pentagonal
markings are seen to cover the surface.
Although the beetle has been known for
more than a century, the egg has been
but recently described by Mr. +. I'll. Chit
tenden, of the division of entomology OF
the United States department of aSricul-
ture.
Larva.-In the grub" or larval stage,
! the insect is probably usually overlooked.
/ 1t is n slim "wire-worm" like creature.
with black head and tail, and the two
ends are not readily distinguished. The
| body is soft, whitish, cylindrical. measur-
ing about one-fourth of an inch in length
Pupa-The pupa is quite small. white.
| measuring about seventeen hundredths
of an inch in length. Under a hand
lens a few scattering hairs. or setae. are
to be seen distributed over the body, ana
| from the caudal end project two long
acute spines, arising from Il common base.
Adult-In this stage the insect Is so
we'll known as the cucumber beetle that
/ the following brief description VIII be
! unnecessary to many. The beetle Is about
two-ffths of an inch in length, and about
one-half as wide as long. In color IL
Is yellowish above, with head black, and
with three black stripes extending down
the wing covers. The central stripe IS
formed by a narrower stripe on the inner
margin of each wing cover. Below. the
insect is ather uniformly back. with the
femora of the legs yellow.
LIFE, HISTORY AND HABITS.
The winter is passed in the adult or
beetle stage in the ground or under trash
where sufficient protection is afforded
from the cold They come from their
winter quarters during the warm spring
with ravenous appetites and attack va
riOus kinds of foliage with much NiSor'
At this time, they are not very particular
as to what they eat. nor the condition
in which it is in; dirty. tough ana even
poisoned foliage may be eaten with avid
ity In the course of a few days OF
feeding. they become somewhat satiated,
&
condition of their food. Coming from
winter quarters. as they do, about the
time that early cuCurbitS are pushlnS
through the soil, these plants are attack
ed and may be quite destroyed. After
four or five days of feeding, their hum
ger being appeased. mating usually be
gins Their food is now confined prin-
cipally TO the tender parts of plants and
flowers. and it is difficult to induce them
to feed on foliage of any kind, coated
with foreign substances, as any of the
common arsenites.
The eggs are dropped, according 10 Pro-
fessor Shrine, here and there on the vines
or ground. the beetles are feeding.
The resulting larvae pass to the soil and
feed on the vines and fruit, where these
come in contact with moist earth These
larvae are capable of doing considerable
injury to cucurbit vines. by eating holes
into the tissues, thus greatly weakening
the plant and affOrdng an entrance for
various forms of decay. To the fruit,
of the cantaloupe particularly, INJURY
consists mainly in causing Il roughcned
and warty appearance on the side next
to the soil. and to a certain extent rem
dering them less valuable for market pur-
poses. The length of the larval stage
doubtless varies considerably, depending
on the food supply. Upon arriving at
maturity, however the pupal state is en-
tered, I'm the course of a few days, from
which condition adults emerge during the
course of one or two weeks. The length
of life of an adult may extend over con-
siderable period. according 10 Professor
Shrine. at least in New York state. where
he found that the beetles seen in Septem-
Der and October hibernate during the win
ter and may live toward the end of July
of the following summer.
REMEDIAL AND PREV ENTlNE
MEASURES.
Under this head could be collected an
enormous amount of literature that has
been written 10y entomologists, editors of
agricultural and horticultural papers, and
others. during the last fifty or more years;
but despite these volumiuous writings,
a simple and thoroughly effective RENE
dy is still desideratum. There seems
to be no one insectcide, or line of treat
ment, that is of itself satisfactory, and
the best results are doubtless to be OBJ
tanned where several methods are used
in conjunction.
The direct application of poisons to the
foliage of cucurbits has not proved to be
very satisfactory as a remedy, particular
ly where the beetles are abundant. The
foliage of these plants is very sensitive,
and when the arsenites are used sufficient
ly strong To kill the beetles, a burning or
scalding of the foliage is almost sure to
result.
Various kinds of covers have been
recommended for covering the plants as
they are pushing through the soil, and
later. Among those most commonly used
are ordinary boxes with top and bottom
open, the top being covered with cheese
cloth. a dome-ike covering may be
easily made by crossing TWO halves of a
barrel hoop and putting on Il cover of
81 Of et III.
of the cut hoops may be settled I'm the
ground and serve To hold the cover in
place. Certain wire covers have been
patented and are used extensively by
some growers. These cost cents each
but may be used for several years
Planting an excess of seed is advisable
as the injury becomes more distributed. |
and after the beetles have satisfied their
hunger the plants should be thinned out
TO the proper stand. Early planting also
will frequently allow the plants to get
well started before the beetles make their
appearance and their effects on the plants
will not be so severe. Where practicable |
1t Is advisable to start the plants under |
coVes. In pots, setting them out when |
danger from frost is over; this not only
enables the grower to escape the loss |
from the cucumber beetle to a consider !
able extent, but should give him an
earlier and hence more valuable crop.
Those who have examined into the 1
habits of these beetles to any extent have /
doubtless noticed how they collect in the I