November, 1890. 
195 
ORCHRRD f! rnd^ GI\RDE N 
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The Bean Weevil. 
( Bruclius dbsoletus. Say.) 
One of the injurious insects which is 
always a source of great annoyance is the 
bean weevil, Bruclius obsoletus. It is com- 
monly called the Bean 
bug. Strictly speaking 
it is not a bug bnt a 
beetle. Bugs are al- 
ways furnished with 
hauslellate or sucking 
mouth parts, while 
beetles have biiing 
mouth parts. Such is 
Fig-, l, the bean weevil. Close- 
ly related to the bean weevil are the pea 
w'eevil and the grain weevil. 
The Bean weevil (Fig. 1) is a small, tawny- 
grav beetle which is often found in immense 
numbers infesting beans. Perhaps the first 
indications that they are present will be the 
immense number of “bugs”among the beans, 
and the general appearance 
of the beans. Numerous 
small holes (Fig. 2), having 
the appearance of being eat- 
en, will cover the beans. These 
latter have been the homes 
of the beetle during tw T o 
successive stages of develop- 
ment — that of the larva and pupa. 
The bean weevil in its habits very much 
resembles the pea weevil. The eggs are 
not, as is generally supposed, deposited 
upon the beans, but are placed upon the 
outside of the pods. The eggs are fastened 
to this by a sticky fluid. Generally, each 
pea has only one weevil, but with the bean 
weevil any number may be found. I have 
found as many as twenty-five infesting one 
bean. The place where the larva enters the 
bean can seldom be seen, as in the case with 
the pea weevil. The cavity in which the 
insect reaches maturity is rounded on all 
sides, and is perfectly smooth. The pupae 
and mature beetles can be seen packed away 
snugly in their prison homes in the white 
varieties of beans. Seldom is the germ of 
the bean injured, and if only a few of the 
weevils are present there is no doubt but 
that they will grow, although the vitality 
of the plant would be greatly lessened. 
Many of the insects reach maturity in the 
fall, but the larger number not until spring. 
“The general color of the bean weevil is 
tawny -gray, the ground color being dark, 
and the whole body covered with a grayish 
pubescence which inclines to yellow, or 
fulvous, or wears a slight, moss-green hue. 
It is about half the size of the pea weevil, 
and has the four or five basal joints of the 
antennae and the legs, with the exception of 
the lower and inner part of the hind thighs, 
reddish-browm” (Riley). 
As a remedy for these pests nothing can 
be better than Bisulphide of Carbon. This 
is a very volatile liquid with a disagreeable 
odor, and when in combination with air is 
very dangerous if ignited. If the infested 
beans are plac id in a tight receptacle anda 
quantity of the bisulphide thrown in, there 
can be little doubt that every one will meet 
its death. This treatment will destroy 
larvae and papae. The beans on being 
exposed to the air will lose all traces of the 
bisulphide, and will in no wise be injured 
by the treatment. Care must be taken not 
to go near the treated beans with fire until 
all odor of the chemical has disappeared. 
If beans are stored in warehouses the liquid 
may be introduced into the bottom of the 
bins by means of a gas pipe. 
The White Pine Sawfly. 
( Lnphyrus abbntti , Leach.) 
Mr. T. L. Imes, of Brimfield, Ind., sends 
specimens of a larvae from his white pines. 
The specimens sent prove to be the larvae 
of Lophyrus abboUi of Leach. The mature 
insects (Fig. 3) belong to the same order of 
insects as do the bees, ants, and wasps, 
hynenoptera, or, as the name signifies, 
membrane wings. Most members of this 
order are beneficial, but there is one family 
which has proved to be a nuisance, causing 
great damage to garden fruits and ornamen- 
tal trees. This is the family T Tenthredinidcc 
or sawflies. To this family belong the 
strawberry sawfly, the currant slug, the 
pear slug, and the white pine sawfly. They 
are called sawflies from a peculiar piece of 
apparatus situated in the last three segments 
of the body or abdomen. This consists 
usually of two sharp, saw-like pieces or 
blades, by means of which the female cuts 
a groove or slit into the leaves and stems of 
trees. Into this groove she inserts her eggs. 
The pine tree sawfly (Fig. 3) cuts the slit in 
the flat side of the needles, and into this is 
inserted the small white eggs. Within a 
short time a noticeable swelling is seen 
where the eggs were deposited, caused by 
the eggs absorbing moisture, and a conse- 
quent enlargement of the embryo. As soon 
as the eggs hatch, the yoting larvae begin to 
eat the needles or leaflets. Generally they 
feed in flocks, and will destroy nearly the 
entire foliage. They commence eating at 
the tips of the needles, and go toward the 
trunk or twig. The larvae (Figs. 4, 5) vary 
much in size, the average being nearly an 
inch. When first hatched they are of a 
dirty-white color. After the first moult or 
shedding of the 
skin they are 
dotted with 
black. On all 
Fig. 4. the segments 
except the first are two rows of 
dorsal spots. These are somewhat longer 
than wide, and on the last segment 
are usually united. Upon either side 
of each segment is a black spot w T hich 
is somewhat rounded. The larvae are fur- 
nished with twenty-two legs, and in this 
respect can be readily told from true cater- 
pillars — true caterpillars have from ten to 
sixteen legs. The first three pairs of legs 
are black and jointed, while the remainder 
are of a dirty-green. The head after each 
moult is light, but soon changes to a jet 
black. The larvae after attaining their full 
size spin a bright, bronze-yellow cocoon. 
Usually these are attached to the needles or 
twigs, although many pupate in the debris 
under the trees. The larvae are found from 
May until late in November. It appears as 
though the greatest damage is done by the 
last brood during the months of September, 
October, and November. When disturbed 
the larvae throw the 
head and tail ends into 
the air, and if jarred Fig. 5. 
would fall to the ground. 
The following spring the young flies 
appear, and after pairing deposit the eggs 
for another season of depredation. The 
cocoons are opened by a spiral cut made by 
the insect, thus leaving a hinged door to 
their prison home. The two sexes differ 
greatly in size and color. The male is 
almost entirely black, while the female is a 
honey yellow, with the head and thorax 
somewhat darker than the abdomen. “The 
thorax is blackish at the upper posterior 
sides, and the abdomen having a lighter 
yellow lateral stripe, with four or five 
blackish dots above it.” The antennsee in 
both sexes are black, those of the male 
twenty-one jointed, and with seventeen 
long and seventeen short plume-like 
branches The antennas of the female has 
nineteen or twenty joints, The mature flies 
are somewhat irregular about making their 
appearance in the spring, many issuing in 
May, and others not until late summer. It 
is not probable that the flies will be numer- 
ous two years in succession, as they are 
preyed upon by a small ichneumon fly, 
Linneria lophyri. The sawfly seldom attacks 
any trees except the white pine, hence it is 
important that those who have pines as 
ornamental trees should watch them closely. 
A solution of hellebore, about one table- 
spoonful to two gallons of water, sprayed 
upon the trees, will effectually destroy the 
larvae. Paris green and London purple — 
one pound to two hundred gallons of water 
— would perhaps answer the purpose better, 
as it is more virulent in its nature, and no 
harm can result from its use. Lime and 
ashes have been recommended as excellent 
remedies. As the larvae are not covered by 
any slimy secretion, the particles of lime or 
ashes would not adhere to the insect, hence 
it would not prove of any value. The 
fallen needles and other debris under the 
trees should be burned. This will destroy 
all cocoons that have been formed, and will 
materially check the insect. 
