The Florida agriculturist. [volume], July 12, 1893, Image 1

About The Florida agriculturist. [volume] (DeLand, Fla.) 1878-1911

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VoI.IL No. 28. Whole No. 760.
For the Florida agriculturist.
Some Economic Insects.
BY P. H. ROLFS,
Fiofessor of Biology, Florida Agricultural
College, Lake City, Fla.
RTICLE TIIREE.
HEMIPTERA.
Among the true bugs, Hcmiptcra , we
have some very doubtful characters, as
for instance Euscliistus punctipes u brown
ish gray plant bug of medium size that
has the curious habit of puncturing the
green parts of plants for sap, and at other
times taking a fancy to some plump, fat
young larva that may come in its way.
Podisus cynicus, a much larger bug of
about the same shape, and Podisus spin,'
osus , have somewhat similar habit to
that of the bug described above. This
last named bug will be remembered by
many as doing very efficient though
not sufficient work in helping to put
down the Colorado potato beetle. An
other doubtful bug is Raphiqaster hilaris,
Fig. 10, or the green soldier bug.
This insect has been spoken of a num
ber of times as a friend but I have seen
it at work only at sucking the sap from
plants.
Leptoglossus phyllopus is a reddish
brown bug with a dull white belt around
her waist. It is very easily recognized
by the broad, leaf like expansions of its
hindest legs. This is a very shy creature
and can only be carefully watched by
the use of an opera glass. It has often
been reported to do damage to cotton but
Fig. 10.
when the evidence is traced back it all
ends in suppose to be so, or it is so be
cause the plant they are on has been
hurt. It has, however, been seen in the
act of destroying insects.
The wheelbug, or devil’s horse, Prio
notus erv status Fig.ll, is a very common
nsect with us, and one with which you
are all acquainted on account of its size
and peculiar shape. The term wheelbug
has been given to it on account of the half
wheel shaped projection of its thorax.
The eggs are laid in hexagonal masses
on the bark of trees or shrubs usually.
In this state they pass the winter hatch
ing out in February or March into small
lively bugs with a red abdomen. Very
soon these young bugs commence to prey
upon other larvm that they can overcome,
especially the larvae of the tent cater
pillar.
Sometimes, however when driven by
DeLaml, Fla., Wednesday, July 12, 1893.
hunger they feed upon one another.
They feed by inserting their long pro
boscis into the body of their prey and suck*,
ing out the juice. Although they 'may
only use a small portion of it as food the
Fig. 11.
larvae die from the poisonous effects of
the bite. The victim dies in a very
short time after being bitten and then
the bug leisurely sucks out the juices.
The poisonous elfect is often seen when
one of these bugs bite a person. One
case of this kind was as painful as the
sting of a bee.
After considerable growth and the
young has shed its skin several times it
becomes a perfect insect of a dark gray
color, and often an inch long.
Metapodlus femorala is a very large and
a very common bug with us. He is
easily known by his wide leaf like hind
tarsi. If you are not acquainted with
this bug just handle it a while and you
will be looking for a pole cat to take the
scent off your hands. Asa whole it is
of little economic importance with us.
Icerya purchasi Plate VIII. The plates
numbered in Roman letters refer to the
lantern slides used at the meeting at
Pensacola.
I am sure the association will pardon
the digression if I speak a few minutes
on our worst enemies. Although he is
not with us yet we expect him to come
almost any time and the better we know
him the more able we will be to defend
ourselves.
I am now referring to the Fluter
Scale, ( Icerya purchasi ) that is so de
structive to citrus fruits. Like many
other foreigners he is a great deal worse
ilian a native.
The home of this pest seems to be in
Australia. From Australia this bug has
made his way to New Zealand where it is
now firmly established in the native for
ests. In some places it has severely at
tacked the shade trees. It has also
spread to Cape Colony, Southern Africa.
This insect it is quite certain was im
ported into California during the 10’s or
a little earlier on some Acacias. It had
spread over considerable territory before
it attracted much attention. Let me
give you an example of the rapidity with
which it spreads. “In October 1885 a
patch of these insects covering a space
of three or four inches was noticed upon
a limb of an Acacia tree. From these it
spread and in a little more than a year
several orange and lemon trees and other
plants growing closely in an area of
about 100x80 feet had become seriously
infested.”
This scale can thrive on Citrus,
Rose, Acacias. There are many other
food plants but these are the principal.
Also a list upon which they can not.
Pine, Cypress, Eucalyptus, Olives, Pears
and Oleander. Fig. one PI. IX repre
sents an egg greatly enlarged. Of these
a single female may lay from eight hun
dred to eleven hundred in a single mass.
These hatch in from a few days to two
months dependingon the weather.
Fig. 2 PI. IX represents the recently
hatched larva of a reddish color some
what inclined to brown.
Figs. 3, 4 and 5 are different stages of
the female. Fig. 5 represents the adult
female scale insect.
Its color is still a reddish brown and
free from waxy covering. As soon
as the female begins to swell from
the eggs forming inside the beginning of
the egg sack is made.
From a great number of pores on the
sides of the body the wax begins to ex
ude until finally only the head portion
of the inseet is in contact with the bark
of the tree. The egg formation contin
ues until the mass is about twice the
size of the insect.
The mass is of a snow white color with
fifteen ridges or Hidings of subequal
size. From this waxy cocoon the young
scale make their escape as soon as
hatched.
The period of egg depositing is from
one and a half to two and a half months,
depending on conditions. Females on
healthy trees deposit a great many more
eggs than those on sickly trees.
The adult male is a very rare speci
men, probably known only to entomol
ogists.
HOW THEY DAMAGE TREES.
A newly hatched larva seeks a leaf
and settles on it (takes a home stay; no a
tree claim) and inserts its beak into the
tender leaf, ft now commences to pump
out the sap. After moulting the third
time it passes down to the young branches.
As soon as full grown the female seeks
s une favorable place to commence her
incubation. She soon becomes station
ary. The males after becoming winged
Fig. 12.
do not feed any more. Their time of flight
is from five o’clock in the evening until
dark. During the rest of the time they
are sluggish and do not tty.
These insects are transported mainly
in their larval state Fig. 2 PL VIII on
scions or nursery stock. They may
also be spread over a limited area by
winds, by birds, and by Hying insects
$2 Ber'Aim iii adract