A. S. (Alpheus Spring) Packard.

Guide to the study of insects, and a treatise on those injurious and beneficial to crops: for the use of colleges, farm-schools, and agriculturists online

. (page 13 of 29)
Online LibraryA. S. (Alpheus Spring) PackardGuide to the study of insects, and a treatise on those injurious and beneficial to crops: for the use of colleges, farm-schools, and agriculturists → online text (page 13 of 29)
Font size
QR-code for this ebook

wait, however, for one brood to be hatched before laying the
eggs of another ; but, as soon as food enough has been collected,
she lays the eggs for a second. The eggs [Plate 4, Fig. 2]
are laid, in contact with each other, in one cavity of the mass
of pollen, with a part of which they are slightly covered. They
are very soon developed ; in fact, the lines are nowhere dis-
tinctly drawn between the egg and the larva, the larva and
pupa, and again between the latter and the imago ; a perfect
series, showing this gradual transformation of the young to the
imago, can be found in almost every nest.

"As soon as the larvae are capable of motion and commence
feeding, they eat the pollen by which they are surrounded, and,
gradually separating, push their way in various directions.
Eating as they move, and increasing in size quite rapidly, they
soon make large cavities in the pollen mass. When they have
attained their full size, they spin a silken wall about them,
which is strengthened by the old bees covering it with a thin
layer of wax, which soon becomes hard and tough, thus form-
ing a cell. [Plate 4, Figs. 1, 2.] The larvae now gradually
attain the pupa stage, and remain inactive until their full devel-


opmcnt. Tlicy then cut their way out, and aro ready to assume
their duties MS workers, small females, males or queens.

"It is apparent that the irregular disposition of the cells is
due to their being constructed so peculiarly l>y the larva-.
After the first brood, composed of workers, has come forth,
the queen bee devotes her time principally to her duties at
home, the workers supplying the colony with honey and pollen.
As the queen continues prolific, more workers are added, and
the nest is rapidly enlarged.

"About the middle of summer eggs are deposited which
produce both small females and males." . . . "All eggs laid
after the last of July produce the large females, or queens ;
and, the males being still in the nest, it is presumed that the
queens are impregnated at this time, as, on the approach of
cold weather, all except the queens, of which there are several in
each nest, die." (Putnam, Com. Essex Inst., vol. iv, p. 98, 1864.)

Besides Apathus, the larvae of various moths consume the
honey and waxen cells ; the two-winged flies, Volucella and
Conops, and the larvae of what is either an Anthomyia or
Tachina-like fly ; several species of Anthrax, the Coleopterous
Anobium paniceum of Europe, Meloe, Sty lops, and Anthero-
phagus ochraceus are parasitic on Humble-bees.*

The habits of the genus Apathus are not clearly known, but
they are supposed to prey, in the larva state, upon the larvae of
Bombus, being found in their nests ; their habits, so far as
known, ally them with Nomada. The species are distinguished
by the tibioe being convex, instead of concave, as in Bombus,
while the mandibles of the females are acute, triangular, biden-
tate, being spatulate and three-toothed in Bombus, and they
have no pollenigerous organs. There are males and females
only, as in all the remaining genera of the family. Apathus
Ashtonii (Plate 3, Fig. 1) is found in the Northern States.

* EXPLANATION OF PLATE 3. Pafrasites of the Humble and Leaf-cutter Bees.
Fig. 1, Apathus Ashtonii. Fig. 2, Nephopteryx Edmandsii; a, larva; 6, pupa. Fig.
3, 3rt, Microgaster nephoptericis, an Ichneumon parasite of Nephopteryx. Fig. 4,
Antin rophagus ochracetts. Fig. 5, Anthomyial larva; a, side view. Fig. 6, Re-
cently hatched larva of Stylops Childrenii; o, side view. Fig. 7, larva; a, pupa of
Anthophorabin inrr/nchilix, a Chalcid parasite on Megnchile. Fig. 8, Pteratnnm*
rnt)i<nnii, an exceedingly minute Proctotrupid fly, supposed to be parasitic on An-
thorphorabia megachilis; o, a hind wing. Fig. 9, a. Mite found in the nests of


Xylocopa, the Carpenter-bee, is "the largest and most bulky
of all known baes," but less hirsute than Bombus, while the
basal joint of the labial palpi is almost four times as long as
the second ; and the maxillary palpi are six-jointed, the mouth-
parts being very highly organized. The larva of X. Virginica
(Plate 4, Fig. 3, adult ; Fig. 4, larva ; Fig. 5, nest) is slenderer
than that of Bombus, the body tapering more rapidly towards
each end.

The power of boring the most symmetrical tunnels in solid
wood reaches its perfection in the large Virginian Carpenter-
bee (Xylocopa Virginica). We have received from Mr. James
Angus, of West Farms, N. Y., a piece of trellis for a grape-
vine, made of pine wood, containing the cells and young in
various stages of growth, together with the larvae and chrysa-
lids of Anthrax sinuosa (Plate 4, Fig. 6, larva; Fig. 7, pupa),
a species of fly parasitic on the larva of the bee, and which
buries its head in its soft bod} T and feeds on its juices.

Mr. Angus thus writes us regarding its habits, under date of
July 19 : "I asked an intelligent and observing carpenter yes-
terday, if he knew how long it took the Xylocopa to bore her
tunnel. He said he thought she bored about one-quarter of an
inch a day. I don't think myself she bores more than one-
half inch, if she does that. If I mistake not, it takes her
about two days to make her own length at the first start ; but
this being across the grain of the wood may not be so easily
done as the remainder, which runs parallel with it. She always
follows the grain of the wood, with the exception of the en-
trance, which is about her own length. The tunnels run from
one to one and a half feet in length. They generally run in
opposite directions from the opening, and sometimes other gal-
leries are run above the first, using the same opening. I
think they only make new tunnels when old ones are not to be
found, and that the same tunnels are used for many years.
Some of the old tunnels are very wide. I have found parts of
them about an inch in diameter. I think this is caused by
rasping off the sides to procure the necessary material for con-
structing their cells. The partitions are composed of wood-
raspings, and some sticky fluid, probably saliva, to make it


"The tunnels are sometimes taken possession of by other
bees and wasps. I think when this is the case, the Xylocopa
prefers making a new cell to cleaning out the mud and rubbish
of the other species. I frequently find these bees remaining
for a long time on the wing close to the opening, and bobbing
their heads against the side, as if fanning air into the opening.
I have seen them thus employed for twenty minutes. Whether
one bee, or more, makes the tunnel, that is, whether they take
turns in boring, I cannot say at present. In opening the cells,
more than one are generally found, even at this season. About
two weeks ago, I found as many as seven, I think, in one." *

The hole is divided by partitions into cells about seven-tenths
of an inch long. These partitions are constructed of the
dust or chippings made by the bee in eating out her cells, for
our active little carpenter is provided with strong cutting jaws,
moved by powerful muscles, and on her legs are stiff brushes
of hair for cleaning out the tunnel as she descends into the
heart of the solid wood. She must throw out the chips she
bites off from the sides of the burrow with her hind legs, pass-
ing the load of chips backwards out of the <;ell with her fore-
limbs, which she uses as hands.

The partitions are built most elaborately of a single flattened
band of chips, which is rolled up into a coil four layers deep.
One side, forming the bottom of the cell, is concave, being

* " Since writing the above I have opened one of the new holes of Xylocopa
which was commenced between three and four weeks ago, in a pine slat used in
the staging of the greenhouse. The dimensions were as follows: Opening fully
3-8 wide ; depth 7-1(5 ; whole length of tunnel 6 and 5-1(5 inches. The tunnel branched
both ways from the hole. One end, from opening, was 2 and 5-8, containing three
cells, two with larva and pollen, the third empty. The other side of the opening, or
the rest of the tunnel, was empty, with the exception of the old bee (only one) at
work. I think this was the work of one bee, and, as near as I can judge, about
twenty-live days' work. Width of tunnel inside at widest JMG inch.

For some days this bee has been discharging a great quantity of saw-dust and
pollen, which I had collected by placing a vessel under it. It would seem that she
had cells constructed also in the opposite side of the hole, and that she removed
them to enlarge the tunnel. Among the stuff thrown out, I find a partition of a cell
nearly entire.

I have just found a Xylocopa bobbing at one of the holes, and in order to ascer-
tain the depth of the tunnel, and to see whether there were any others in them, I
sounded with a pliable rod, and found others in one side, at a depth of live and one
half inches; the other side was four inches deep, without bees. The morning was
cool, so that the object in bobbing could not be to introduce fresh currents of air,
but must have had some relation to those inside. The legs on such occasions are,
as 1 have noticed, loaded with pollen." American Naturalist, vol. 1, p. 370.


beaten down and smoothed off by the bee. The other side of
the partition, forming the top of the cell, is flat and rough.

At the time of opening the burrow, July 8th, the cells con-
tained nearly full-grown larvae, with some half developed.
They were feeding on the masses of pollen, which were as large
as a thick kidney-bean, and occupied nearly half the cell. Sa-
pyga repanda is parasitic in the cells of Xylocopa violacea of
Southern Europe.

The habits and structure of the little Ceratina ally it closely
with Xylocopa, as it hollows out the stems of plants, and builds
in them its cylindrical cells. This bee is oblong in form, with
tridentate mandibles, and a short labrum. The maxillary palpi
are six-jointed, and the labial palpi are two-jointed. Ceratina
dupla Say is a common small bright-green smooth-bodied species,
which, in the middle of May, according to Dr. Harris' MS. notes,
tunnels out the stems of the elder or blackberiy, syringa, or any
other pithy shrub, excavating them often to a depth of six or
seven inches, and even, according to Mr. Haldeman (Harris
MS.), bores in acorns. She makes the walls just wide enough
to admit her body, and of a depth capable of holding three or
four, often five or six cells (Plate 4, Fig. 11). The finely built
cells, with their delicate silken walls, are cylindrical and nearly
square at each end, though the free end of the last cell is
rounded off. They are four and a half tenths of an inch long,
and a little over one-third as broad. The bee places them at
nearly equal distances apart, the slight interval between them
being filled in with dirt.

Dr. T. W. Harris* states that, "May 15, 1832, one female
laid its eggs in the hollow of an aster-stalk. Three perfect in-
sects were disclosed from it July 28th." The observations of Mr.
Angus, who saw some bees making their cells, May 18th, also
confirms this account. The history of our little upholsterer is
thus cleared up. Late in the spring she builds her cells, fills
them with pollen, and lays one or more eggs upon each one.
Thus in about two months the insect completes its transforma-
tions ; within this period passing through the egg, the larval
and chrysalid states, and then, as a bee, living through the win-
ter. Its life thus spans one year.

* According to a note in MSS. deposited in the Library of the Boston Society of
Natural History.

APIARL*. 135

The larva (Plate 4, Fig. 10) is longer than that of Mega-
ohile, and compared with that of Xylocopa, the different seg-
ments are much more convex, giving a serrate outline to the
bark of the worm. The pupa, or chrysalis, we have found in
the cells the last of July. It is white, and three-tenths of an
inch long. It differs from that of the Leaf-cutter bee in having
four spines on the end of the bod}', and in having a much
longer tongue and maxilla?, both being almost twice as long.

In none of the wild bees are the cells constructed with more
nicety than those of our little Ceratina. She bores out with
her jaws a long deep well just the size of her body, and then
stretches a thin delicate cloth of silk, drawn tight as a drum-
head, across each end of her chambers, which she then fills with
a mixture of pollen and honey.

Her young are not, in this supposed retreat, entirely free
from danger. The most invidious foes enter and attack
them. Three species of Iclmeumoji-flies, two of which belong
to the Chalcid family, lay their eggs within the body of the
larva, and emerge from the dried larva and pupa skins of the
bee, often in great numbers. The smallest parasite, belonging
to the genus Anthophorabia (so called from being first known
as a parasite on another bee, Anthophora), is a minute species
found also abundantly in the tight cells of the Leaf-cutter bee.

The species of Anthidmm, according to Smith, are gaily
marked with 3 r ellow bands and spots ; the ligula is almost twice
as long as the labial palpi, and acutely pointed ; the paraglossae
are short, the maxillary palpi are two-jointed, and there are two
subcostal cells. The males are longer than the females, with an
elongated and stoutly toothed abdominal tip. The female lines
her nest, situated in any hole convenient for its purpose, with
down from woolly-stemmed plants. They pass the winter in
the larva state, and the bees do not appear until mid-summer.
The species mostly occur in the old world.

In Anthophora, which approaches nearer to Bombus in its
.plump and hairy body than the two preceding genera, the lig-
ula is twice as long as the labial jnaxillse, ending in a bristle-
like point ; the basal joint of the hind tarsus is thickly hirsute,
while the middle tarsus of the males is generally elongated.
The species are gregarious, their numerous cells, while indcpen.


dent, are crowded together in grassy banks. Species of
Melecta are parasitic on them, ovipositing in their cells. The
larvae are infected by the Chalcid flies, Anthophorabia and
Monodontomerus, and by a peculiar species of Mite, Hete-
ropus ventricosns, described by Newport. Say has described
Anthophora abrupta and A. taurea from Indiana.

In Eucera the antennae are very long, while the body is still
plump and hairy : our more common form in the Middle States
is Eucera maculata St. Fargeau. The species are likewise
gregarious, and, according to Smith, their habits are precisely
the same as those of Anthophora.

In Megachile, the Leaf-cutter Bee, the head is broad, the
body stout, oblong, the ligula is about one-half longer than
the labial palpi, being quite stout, while the paraglossse are
short and pointed ; the maxillae are long and sabre-shaped,
while their palpi are short and two-jointed. There are two
subcostal cells in the fore wing. It is a thick-bodied bee, with
a large square head, stout scissor-like jaws, and with a thick
mass of dense hairs on the under side of the tail for the pur-
pose of carrying pollen, since it is not provided with a pollen
basket as in the Honey and Humble-bees. The larva is broader
and flatter than that of Bombus, the raised pleura! region is a
little more prominent, and the raised, thickened tergal portion
of each ring is more prominent than in Bombus.

The Megachile lays its eggs in burrows in the stems of the
elder (Plate 4, Fig. 2), which we have received from Mr.
James Angus ; w r e have also found them in the hollows of the
locust tree. Mr. F. W. Putnam thus speaks of the economy
of M. centuncularis, our most common species. "My attention
was first called, on the 26th of June, to a female busily en-
gaged in bringing pieces of leaf to her cells, which she was build-
ing under a board, on the roof of the piazza, directly under
my window. Nearly the whole morning was occupied by the
bee in bringing pieces of leaf from a rose-bush growing about
ten yards from her cells, returning at intervals of a half minute
to a minute with the pieces which she carried in such a manner
as not to impede her walking when she alighted near her hole.
[We give a figure of the Leaf-cutter bee in the act of cutting
out a circular piece of a rose-leaf (Plate 4, Fig. 8). She


alights upon the leaf, and in a few seconds swiftly runs her
scissors-like jaws around through the leaf, bearing off the
pieee in her hind legs.] About noon she had probably com-
pleted the cell, upon which she had been engaged, as, during
tlie afternoon, she was occupied in bringing pollen, preparatory
to laying her single egg in the cell. For about twenty days
the bee continued at work, building new cells and supplying
them with pollen. ... On the 28th of July, upon removing
the board, it was found that the bee had made thirty cells,
arranged in nine rows of unequal length, some being slightly
curved to adapt them to the space under the board. The
longest row contained six cells, and was two and three-quarters
inches in length; the whole leaf-structure being equal to a
length of fifteen inches. Upon making an estimate of the
pieces of leaf in this structure, it was ascertained that there
must have been at least a thousand pieces used. In addition
to the labor of making the cells, this bee, unassisted in all her
duties, had to collect the requisite amount of pollen (and
honey?) for each cell, and lay her eggs therein, when com-
pleted. Upon carefully cutting out a portion of one of the
cells, a full-grown larva was seen engaged in spinning a slight
silken cocoon about the walls of its prison, which were quite
hard and smooth on the inside, probably owing to the move-
ments of the larva, and the consequent pressing of the sticky
particles to the walls. In a short time the opening made was
closed over by a very thin silken web. The cells, measured on
the inside of the hard w r alls, were .35 of an inch in length, and
.15 in diameter. The natural attitude of the larva is some-
what curved in its cell, but if straightened, it just equals the
inside length of the cell. On the 31st of July, two female
bees came out, having cut their way through the sides of their
cells." In three other cells "several hundred minute Ichneu-
mons [Anthophorabia megachilis] were seen, which came forth
as soon as the cells were opened." (Com. Essex Inst., vol. iv,
p. 105, 1864.)

Meyachile integer Say MS., according to Dr. Harris (MS.
notes), forms its nest of leaves the first of August. This spe-
cies is twice as large, but closely resembles Megachile brevis of
Say. The front of the head is covered with dense ochreoua


hairs, becoming shorter and black on the vertex. The nest,
preserved in the Harris collection, now in the Museum of the
Boston Society of Natural History, is made of rose-leaves, and
is scarcely distinguishable from that of M. centuncularis.

Osmia, the Mason Bee, is another genus of Carpenter or
Upholsterer bees. The species are generally bluish, with
greenish reflections, with smooth shiny bodies, and the species
are of smaller size than in Megachile. The tongue in this
genus is three times as long as the labium, tapering from the
base to the acute apex, and clothed with short hair.

Mr. -F. Smith states that the larva of the English species
hatch in eight days after the eggs are laid, feeds ten to twelve
days, when it becomes full-grown, then spins a thin silken
covering, and remains in an inactive state until the following
spring, when it completes its transformations.

The habits of the little Mason-bees are quite varied. They
construct their cells in the stems of plants and in rotten posts
and trees, or, like Andrena, they burrow in sunny banks. An
European species selects snail-shells for its nest, wherein it
builds its earthen cells, while other species nidificate under
stones. Curtis found two hundred and thirty cocoons of a
British species ( Osmia paretina) , placed on the under side of
a flat stone, of which one-third were empty. Of the remainder,
the most appeared between March and June, males appearing
first ; thirty-five more bees were developed the following spring.
Thus there were three successive broods for three succeeding
years, so that these bees lived three years before arriving at

Mr. G. R. Waterhouse, in the Transactions of the Entomo-
logical Society of London, for 1864 (3d series, vol. 2, p. 121),
states that the cells of Osmia leucomelana "are formed of mud,
and each cell is built separately. The female bee, having de-
posited a small pellet of mud in a sheltered spot between some
tufts of grass, immediately commences to excavate a small
cavity in its upper surface, scraping the mud away from the
centre towards the margin by means of her jaws. A small
shallow mud-cup is thus produced. It is rough and uneven on
the outer surface, but beautifully smooth on the inner. On
witnessing thus much of the work performed, I was struck with


three points. First, the rapidity with which the insect worked ;
secondly, the tenacity with which she kept her original position
whilst excavating ; and thirdly, her constantly going over
work which had apparently been completed. . . . The lid is
excavated and rendered concave on its outer or upper surface,
and is convex and rough on its inner surface ; and, in fact, is a
simple repetition of the first-formed portion of the cell, a part
of a hollow sphere."

The largest species of Osmia known to us is a very dark-blue
species which seems to be undescribed. We will call it the
wood-boring Osmia (Osmia lignivora). It is larger than
the Osmia Ugnaria of Say, being just half an inch long. The
head is much shorter, and less square than in Say's spe-
cies. The front of the head below the antennae is clothed with
dark hairs, but above and on the thorax with yellowish ochreous
hairs. The body is deep blackish blue, with greenish reflec-
tions. We are indebted to a lady for specimens of the bees
with their cells, which had been excavated in the interior of a
maple tree several inches from the bark. The bee had industri-
ously tunnelled out this elaborate burrow (Plate 4, Fig. 12),
and, in this respect, resembles the habits of the Carpenter-bee
(Xnlocopa) more closely than any other species of its genus.

The tunnel was over three inches long, and about three-
tenths of an inch wide. It contracted a little in width between
the cell, showing that the bee worked intelligently, and wasted
no more of her energies than was absolutely necessary. The
burrow contained five cells, each half an inch long, being
rather short and broad, with the hinder end rounded, while the
opposite end, next to the one adjoining, is cut off squarely.
The cell is somewhat jug-shaped, owing to a slight constriction
just behind the mouth. The material of which the cell is com-
posed is stout, silken, parchment-like, and very smooth within.
The interstices between the cells are filled with rather coarse
clippings made by the bee.

The bee cut its wa} r out of the cells in March, and lived for
a month afterwards on a diet of honey and water. It eajn-rly
lapprd up the drops of water supplied by its keeper, to whom
it soon grew accustomed, and seemed to recognize.

The female of Osmia Uynaria Say MS., according to Dr.


Harris' MS. notes, was found in the perfect state in cocoons
within earthen cells under stones, April 15th. The cell she con-
structs is half an inch long, oval, cylindrical, and contracted
slightly into a sort of neck just before the opening for the exit
of the bee. From Mr. James Angus I have received the pellets
of pollen, about the size of a pea, in which it deposits its eggs ;
the larvae were about one-third grown in August.

This species is larger than Osmia simillima of Smith, while
the male antennae are much paler, being fuscous. The front
of the head is covered with long dense yellow ochreous hairs.
The vertex is not of so dark a green as in 0. simillima , and
is covered with coarse punctures. The thorax is heavily clothed
with yellow ochreous, thick hairs. The abdomen is yellowish,
and much more hairy. The legs are stout, fuscous, with yel-
lowish hairs. Length, thirty-five inches.

Our smallest and most abundant species is the little green
Osmia simillima of Smith. It builds its little oval, somewhat
urn-shaped cells, against the roof of the large deserted galls of
the oak-gall fly (Diplolepis confluentus), placing them, in this
instance, eleven in number, in two irregular rows, from which

Online LibraryA. S. (Alpheus Spring) PackardGuide to the study of insects, and a treatise on those injurious and beneficial to crops: for the use of colleges, farm-schools, and agriculturists → online text (page 13 of 29)