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OCIAL

SOLITARY

EUZABETH G.
PBCKH AM

m
o

WASPS

SOCIAL AND SOLITARY

Page 266

PELOP/EUS ON NEST, GROUP OF FINISHED CELLS, AND TUBE OPENED

TO SHOW SPIDERS

WASPS

SOCIAL AND SOLITARY

GEORGE W. PECKHAM

AND

ELIZABETH G. PECKHAM

WITH AN INTRODUCTION BY

JOHN BURROUGHS

ILLUSTRATIONS BY JAMES H. EMERTON
" Bold sons of air and heat, untamed, untired." — ILIAD, Book XVII

BOSTON AND NEW YORK

HOUGHTON, MIFFLIN AND COMPANY

(Cbe 0itoer?ibc p>res$, Cambribge

1905

Published Afril, 7905

NOTE

A PART of the matter presented in this volume was
published several years ago by the Wisconsin Biological
Survey, under the title ' Instincts and Habits of the
Solitary Wasps." These chapters have been revised
and modified, and new matter based upon later work
has been added, in the hope that in their present less
technical form the observations recorded will be of in-
terest to the general reader.

For a number of the text cuts used in this volume we
are indebted to the courtesy of Dr. E. A. Birge, Direc-
tor of the Wisconsin Geological and Natural History
Survey.

CONTENTS

CHAPTER PAGE

I. COMMUNAL LIFE i

II. AMMOPHILA AND HER CATERPILLARS . 15

III. THE GREAT GOLDEN DIGGER ... 56

IV. SEVERAL LITTLE WASPS . . . . 72
V. CRABRO ....... 97

VI. AN ISLAND SETTLEMENT . . . . 119

VII. THE BURROWERS ...... 141

VIII. THE WOOD-BORERS 178

IX. THE SPIDER-HUNTERS . . . 196

X. THE ENEMIES OF THE GRASSHOPPER . 248

XI. WORKERS IN CLAY . . 265

XII. SENSE OF DIRECTION . 275

XIII. INSTINCT AND INTELLIGENCE . . . 292

31254

LIST OF ILLUSTRATIONS

PAGE

PELOP^EUS ON NEST, GROUP OF FINISHED CELLS, AND

TUBE OPENED TO SHOW SPIDERS (page 266) Frontispiece

WASP EATING ........ 3

PAPER NEST WITH SIDE REMOVED TO SHOW CON-
STRUCTION OF COMBS . . . . . ii

AMMOPHILA URNARIA CARRYING CATERPILLAR TO

NEST ........ 19

AMMOPHILA URNARIA STINGING CATERPILLAR . 27

CATERPILLAR WITH EGG OF AMMOPHILA URNARIA 29

NEST OF AMMOPHILA 31

AMMOPHILA URNARIA USING STONE TO POUND DOWN

EARTH OVER NEST ..... 39

THOROUGH LOCALITY STUDY BY SPHEX . . 59
HASTY LOCALITY STUDY BY SPHEX . . .61

SPHEX DRAGGING GRASSHOPPER TO HER NEST . 63

NEST OF SPHEX 69

OXYBELUS QUADRINOTATUS ..... 75

NEST OF OXYBELUS ...... 79

APORUS FASCIATUS ...... 81

WASP HOMES IN THE LOG CABIN .... 85

NEST OF PERENNIS 89

NEST OF ANORMIS . . . . . . 91

LIST OF ILLUSTRATIONS

PAGE

SEXMACULATUS IN THE LINDEN ROOTS . . 99
CRABRO AND HER WHITE MOTHS . . . .103

CRABRO STIRPICOLA . . . . . . 106

BOTTLE ON STEM TO MEASURE WORK OF CRABRO . 107

NEST OF C. STIRPICOLA 113

AMMOPHILA SLEEPING IN THE GRASS (AFTER

BANKS) 115

NEST OF BEMBEX 125

BEMBEX SPINOL^E LOOKING OUT OF NEST . -131

BEMBEX 136

A CORNER OF THE BEMBEX COLONY . . . 137
NEST OF CERCERIS NIGRESCENS .... 142

CERCERIS CLYPEATA 143

CERCERIS DESERTA : LOCALITY STUDY BEFORE LEAV-
ING NEST 153

PHILANTHUS PUNCTATUS . . . . . 157
NEST OF PHILANTHUS PUNCTATUS . . . 163
APHILANTHOPS GATHERING ANTS . . . .169
TRYPOXYLON RUBROCINCTUM . . . . 185
MALE TRYPOXYLON AWAITING THE FEMALE . .191
TORNADO WASP (POMPILUS QUINQUENOTATUS) DIG-
GING NEST ... . . . . . 197

POMPILUS QUINQUENOTATUS 199

EPEIRA STRIX PARALYZED AND HUNG UP ON BEAN
PLANT BY POMPILUS QUINQUENOTATUS, OUT OF
THE WAY OF ANTS ..... 203
NEST OF P. QUINQUENOTATUS . . . .213
POMPILUS MARGINATUS 223

LIST OF ILLUSTRATIONS

PAGE

THE HOME-COMING OF SCELESTUS .... 241
NEST OF AGENIA BOMBYCINA .... 245
LYCOSA KOCHII, FOUND IN NEST OF AGENIA BOM-
BYCINA 245

TACHYTES 249

NEST OF TACHYTES. . . . . . -251

CHLORION AND THE INDISCREET CRICKET . . 257
HORIZONTAL CELLS OF THE MUD-DAUBER . .271
COURSE FOLLOWED BY POMPILUS FUSCIPENNIS IN
FINDING HER SPIDER, AND IN RETRACING HER

STEPS TO THE NEST 283

LOCALITY STUDY OF ASTATA BICOLOR . . 288

LOCALITY STUDY OF ASTATA UNICOLOR . . . 289

SECOND LOCALITY STUDY OF ASTATA UNICOLOR 290
PARALYZED SPIDER HUNG UP ON SORREL BY QUIN-

QUENOTATUS WHILE SHE DIGS HER NEST . 295

>-'

IbU

Introduction

NOT long since I wrote to a friend, a nature lover,
as follows: "The most charming monograph in
any department of our natural history that I have read
in many a year is on our solitary wasps, by George
W. Peckham and his wife, of Wisconsin, - - a work so
delightful and instructive that it is a great pity it is
not published in some popular series of nature books,
where it could reach its fit audience, instead of being
handicapped as a State publication." This end has now
been brought about, and the book — revised and enlarged
with much new material and many new illustrations -
placed within easy reach of all nature lovers, to whom it
gives me pleasure to commend it. It is a wonderful record
of patient, exact, and loving observation, which has all the
interest of a romance. It opens up a world of Lilliput
right at our feet, wherein the little people amuse and
delight us with their curious human foibles and whim-
sicalities, and surprise us with their intelligence and
individuality. Here I had been saying in print that I
looked upon insects as perfect automata, and all of the
same class as nearly alike as the leaves of the trees or

• • •

INTRODUCTION

the sands upon the beach. I had not reckoned with the
Peckhams and their solitary wasps. The solitary ways
of these insects seem to bring out their individual traits,
and they differ one from another, more than any other
wild creatures known to me. It has been thought that
man is the only tool-using animal, yet here is one of these
wasps, Ammophila, that uses a little pebble to pound
down the earth over her nest. She takes the pebble in
her mandibles, as you or I would take a stone in our
hand, and uses it as a hammer to pound down the soil
above the cavity that holds her egg. This is a remark-
able fact ; so far as I know there is no other animal on
this continent that makes any mechanical use of an
object or substance foreign to its own body in this way.
The act stamps Ammophila as a tool-using animal.

I am free to confess that I have had more delight in
reading this book than in reading any other nature book
in a long time. Such a queer little people as it reveals to
us, so whimsical, so fickle, so fussy, so forgetful, so wise
and yet so foolish, such victims of routine and yet so
individual, with such apparent foresight and yet such
thoughtlessness, finding their way back to the same
square inch of earth in the monotonous expanse of a
wide plowed field with unfailing accuracy, and then at
times finishing their cell and sealing it up without the

xiv

INTRODUCTION

spider and the egg ; hardly any two alike ; one nervous
and excitable, another calm and unhurried ; one care-
less in her work, another neat and thorough ; this one
suspicious, that one confiding ; one species digging its
burrow before it captures its game, others capturing the
game and then digging the hole ; one wasp hanging its
spider up in the fork of a weed to keep it away from the
ants while it works at its nest, and then running to it
every moment or two to see that it is safe ; another lay-
ing the insect on the ground while it digs, - - verily a
queer little people, with a lot of wild nature about them,
and of human nature, too.

JOHN BURROUGHS.

WASPS

Social and Solitary

Chapter I

COMMUNAL LIFE

" For where 's the state beneath the firmament
That doth excel the wasps' for government."

" What is not good for the swarm is not good for the wasp."

A) the tendency of mankind to crowd into towns
grows stronger the joys of country life and the
workings of Nature are more and more excluded from
the daily experience of humanity. In a few the primal
love of the wild is too strong for suppression, and turning
from the hot and noisy streets they find it a refreshment
of spirit to meet our little brothers of earth and air in the
wider spaces of their own territory.

We were walking through the woods one hot day in
the middle of August when our attention was attracted
by a stream of yellow-jackets issuing from the ground.
They came in such surprising numbers and looked so

WASPS, SOCIAL AND SOLITARY

full of energy that we stopped to watch them, and this
was our introduction to the study of these "bold sons of
air and heat," although a perusal of Fabre's fascinating
"Souvenirs Entomologiques " had prepared us to feel a
lively interest in them. We -were at our summer home
near Milwaukee, where meadow and garden, with the
wooded island in the lake close by, offered themselves as
hunting grounds, while wasps of every kind, the social-
istic tribes as well as the extreme individualists of the
solitary species, were waiting to be studied.

The Vespas that had aroused our interest received our
first attention, and a nest in the ground proved to be a most
convenient arrangement. Experiments that would have
been dangerous to life and limb had we tried them with
a paper nest hanging in the open, were easy here so long
as we kept calm and unflurried. Intent upon their own
affairs, and unsuspicious of evil, perhaps because they
knew themselves to be armed against aggression, they
accepted our presence, at first with indifference ; but as
we sat there day after day we must have become land-
marks to them, and perhaps before the summer was
over they considered us really a part of home.

While poor humanity takes comfort in a mid-day
siesta, wasps love the heat of noontide, and with every
rise in temperature they fly faster, hum louder, and

COMMUNAL LIFE

rejoice more and more in the fullness of life. The en-
trance to the Vespa nest was but an inch across; and once
when they were going in and out in a hurrying throng,
jostling each other in their eagerness, we counted the
number that passed, one taking the entrances and one

WASP EATING

the exits. In ten minutes five hundred and ninety-two
left the nest and two hundred and forty-seven went in,
so that we saw eight hundred and thirty-nine or about
eighty to the minute. This must be a strong swarm,
wonderful indeed when we thought that it had all come
from a single queen mother. We imagined how she had
made an early start, digging a hole in the ground, build-
ing within it a paper comb with five or six cells around a

WASPS, SOCIAL AND SOLITARY

central column, and laying therein some neuter eggs;
how she had then spent a month in attending carefully
to the beginnings of things, feeding the young larvae as
they hatched, and watching over them through their
childhood and youth; and then how her solicitude was
rewarded by the filial devotion with which this first set of
workers took upon themselves the labor of excavating,
building, and feeding the young, everything indeed except
the egg-laying. These queens, surrounded though they
are by respectful and attentive subjects, have much the
worst of it in our estimation, never going out, and passing
their lives in a dull routine. Through the early summer
only neuters are produced, but when fall approaches the
future generation is provided for by the development of
males and females. The activity of the little colony is
limited by the season, for as the days grow colder the
males and females leave the nest and mate, and a little
later both males and workers lose ambition, become
inactive and finally die, while the queens hide away in
protected corners to reappear in the spring. The eggs
and larvae, left unfed and uncared for, become a prey to
moulds and to hordes of insects, and thus the swarm
comes to an end.

We had once made some not very successful attempts to
find out whether spiders had a sense of color; and seeing

COMMUNAL LIFE

that the conditions were much more favorable with our
present subjects, we thought it would be a good plan to
test their knowledge of the spectrum. Providing six
sheets of stiff paper two feet square, colored respectively
red, blue, green, pink, and two shades of yellow, and cut-
ting a circular hole four and one half inches in diameter
in the centre of each, we began our experiments by pla-
cing the red paper over the nest so that the entrance was
clearly exposed. The outgoing wasps dashed upward
without noticing it, but great was the confusion among
the homecomers. Thrown out of their reckoning, they
clamored about us in ever increasing swarms. Like
Homer's wasps,

" All rise in arms and with a general cry
Assert their domes and buzzing progeny,"

and a crisis (for us) was approaching, when one, a pioneer
of thought, determined to go into the hole, which did not
look like the right hole, although it was where the right
hole ought to be; and so potent is example that one by
one the others followed. Three hours later they had
become accustomed to the change, and went in and out
as usual.

They had noticed the paper ; that was plain enough,
but did they notice the redness? To test this, we left
things as they were for two days, and then substituted

WASPS, SOCIAL AND SOLITARY

blue paper for the red. Again the confusion, the swarm-
ing of fervent legions, the noisy expostulations, the
descent of one after another; but this time they settled
down to their ordinary routine in a little more than two
hours. On the following day we removed the blue paper,
leaving the grass around the nest exposed ; and this
proved a new source of mystification, but not so serious
as the others. At the end of an hour twenty-five or thirty
were still buzzing about, needing the guidance of the
blue paper to get inside, and entering at once when it
was replaced. As we tried new colors from day to day a
few of the wasps became entirely reconciled to our inter-
ference, and paid no attention to the changes, while the
others grew more or less accustomed to the idea of muta-
bility, and were but little disturbed, although they still
showed their consciousness of each alteration by making
a few circles before going in. We once placed some dark
red nasturtiums on light yellow paper near the nest, and
found that more than one third of the homecoming
wasps flew to them and hovered over them before enter-
ing. When light yellow nasturtiums, nearly matching the
paper in color, were substituted, only one out of thirty-
six noticed them; and as the odor was as strong in one
case as the other, it would seem that the color was the
attracting force.

COMMUNAL LIFE

Our final color experiment was to let the blue paper
remain for a day or two, giving time for all the wasps to
become familiar with it, and then to leave it on the
ground a foot and a half away, while replacing it with
yellow. This gave a false nest surrounded by the color
that they had been associating with the entrance, and a
true nest surrounded by a new color. In the next ten
minutes two hundred and seventy wasps came home, and
every one of them went to the false nest. Many circled
above it, others entered the hole in the paper, and some
began to excavate, and made quite a depression in the
ground; but gradually they found their way home.
Three hours later seventy-six wasps entered the false
nest in five minutes, and at evening they were still visiting
it in goodly numbers ; but on the next day we saw only
two that were deceived.

On successive days we substituted red for yellow,
green for red, and so on, always with similar results,
although the wasps became more and more accustomed
to the vicissitudes of their life, and after a time seemed to
look for the hole itself without relying upon the color to
guide them. They found their nest under a color new to
them much more readily than when the paper was taken
entirely away and the ground left exposed. Once when
the green paper was around their nest, and the wind

WASPS, SOCIAL AND SOLITARY

blew it over the hole so that they could not enter, at least
one hundred collected, many of them settling in the false
nest; when we lifted the green paper, leaving the hole
free, only three or four entered, but when we put it back
in place they rushed in six or seven at a time. It was
plainly the color that directed them.

This was a nearly rainless summer, — a condition
extremely favorable to wasp development. Nests multi-
plied and grew until the whole country-side complained,
and no wonder, for houses were full of them, and at meal-
times they gathered at the table with the members of the
family. How did they know when dinner was ready ?
It could not have been by the sight, unfamiliar to them,
of cooked food ; was it, then, through the sense of
smell ?

Many were the questions that we asked in vain of
our Vespas, but here was one that they could readily
be made to answer. We rolled up two bundles, one of
nothing but gauze, and another, like it in appearance,
but containing some warm chicken bones ; these were
laid to one side of the nest, the color of the gauze
matching that of the paper on which it was placed.
The wasps in returning to the nest, even though loaded
with food, could not resist the appetizing odor, and
settled thickly upon the bone bundle, trying their best

COMMUNAL LIFE

to penetrate within, while the empty gauze was un-
noticed. As the bones grew cold and dry they attracted
less attention, but two days later they were occasion-
ally visited.

Having killed two wasps that had alighted on the
ground, by striking them with a folded paper, we took
them up and placed one of them at a distance, so that
it was entirely hidden in the grass. Five settled above
it, and after they had carried it away the place was
visited by several others, while the spot upon which we
had killed them drew to it nine wasps within fifteen
minutes. Thus they seemed very keen of scent where
animal matter was concerned ; but the powerful oils of
peppermint and wintergreen, although noticed, aroused
little attention, perhaps because they indicated nothing
of interest to them.

Our experiments on hearing met with negative results.
The wasps seemed insensible to any noise we could
make or that we could produce by whistles of various
degrees of shrillness. This of course does not show that
they cannot hear, and any one who has been unfortunate
enough to disturb them in the neighborhood of their nest
will remember how their angry buzzing seemed to serve
as a battle cry to gather all the members of the clan for
the attack.

9 /

'<£? •* -

ILU L I

WASPS, SOCIAL AND SOLITARY

Our Vespas began to work an hour or two after sun-
rise, and did not stop until dusk. One cloudy evening
when darkness fell early they continued to return to the
nest, being able to fly to the right spot without any hesi-
tation, although our vision did not permit us to see the
opening without going down on our knees and looking
closely. At last it grew perfectly dark, and we stuffed a
handkerchief into the hole, with the result that seventy-
five, coming home without a ray of light to guide them,
were shut out, and were found clustered about the spot
on the following morning.

We wanted to estimate the amount of labor done by a
worker in a day, and so, rising one morning at the first
bird call, we went out into the freshness of dawn, and for
an hour had the world to ourselves ; but a little before five
a few straggling wasps that had stayed out all night
began to bring in loads, and by half past seven they were
fairly under way. From half past four until twelve we
counted all that passed, 4534 going out and 3362 coming
home; and with all this activity there seemed to be no
pleasure excursions, for each one carried food when
returning, and took out a pellet of earth when leaving.
We once raised a little garden from the pellets that were
dropped on our porch table where we kept a bowl of
water. Wasps are great drinkers, and when they find

COMMUNAL LIFE

such a provision they come frequently to refresh them-
selves, dropping their loads as they alight. This habit
of holding on to their loads until they settle down may
perhaps make them a factor in extending the boundaries
of plant distribution, both under ordinary conditions
and when, as must often happen with little creatures
flying so high, they are blown to long distances from
home.

Having kept close track not only of the numbers, but of
the hours, each count
being made to cover
five minutes, we were
able to calculate that
an average trip occu-
pied forty-three min-
utes. When we met
these wasps in the
garden they never
seemed to be hurry-
ing, and had the air
of amusing them-
selves ; but they must
be faithful workers to
accomplish so much. The curious fact has been estab-
lished that when food is very plentiful the workers

PAPER NEST WITH SIDE REMOVED TO
SHOW CONSTRUCTION OF COMBS

WASPS, SOCIAL AND SOLITARY

begin to lay male eggs, thus taking from the queen a
part of her burden and leaving her free to produce
neuters and females. The nest that we were watching
was found, at the end of the season, to contain 4661
wasps in various stages of development, and others that
we opened had from two to four thousand. This is no-
thing to the social wasps of China, where a single house-
hold is made up of from fifteen to twenty thousand mem-
bers ; but China is a thickly populated country, and per-
haps with wasps as with human beings several families
live in a single domicile.

Outside of their wonderful social instincts our wasps
are found wanting in the higher gifts of emotion and in-
tellect. When we killed a number of them and placed
them near the nest, their nearest relatives wasted no time
in mourning, nor yet in revenge, but calmly cut up the
bodies and fed them to the ever hungry young ones. If
we placed some rich and tempting morsels at a distance,
two or three would discover them, and would go back
and forth all day without telling the others about it, as
ants would have done under like circumstances. When
we obstructed the opening to their nest by lightly laying
blades of grass across, the day passed without its occur-
ring to the wasps to lift them away, although they suf-
fered the greatest inconvenience in getting in and out,

COMMUNAL LIFE

crawling laboriously through, and in some instances giv-
ing up the task and flying away.

Vespa maculata, building on trees and fences, has
practically the same habits as the ground wasp, german-
ica, the internal structure of the nest following the same
plan, while the outer wall is of a papery substance like
that of the combs, made from the scrapings of weather-
beaten wood. The genus Polistes builds combs similar
to that of Vespa, under porches or in any sheltered place,
and does not inclose them. All these wasps, when adult,
enjoy fruit and flowers as well as animal food; but only
this last is used for the young, and many a caterpillar
creeping along with sinister design is snatched by them
to be chewed into a pulpy mass, and then fed to the
larvae. No calculation has been made of the value of
these wasps in agriculture, and one of the things that
farmers have yet to learn is to encourage their presence
in orchards and gardens.

Some species are said to sting the drones and larvae to
death at the close of the season, but this habit is not fol-
lowed by V. germanica and V. maculata. Since there is
no store of provision to be economized through the winter
the only object of such conduct would be the merciful
one of ending their sufferings at once instead of letting
them perish by slow starvation, and we find no evidence

WASPS, SOCIAL AND SOLITARY

for such elevated ideas. What makes for the welfare of
the species they thoroughly attend to, but beyond that
point they do not go.

The socialism of wasps is in a less evolved state than
that of bees and ants, and yet there is in it sufficient sacri-
fice of self to the common good to excite the respectful
wonder of human beings, whose relations to each other
and to the state have such different standards.

Chapter II

AMMOPHILA AND HER CATERPILLARS

BEFORE we had worked long on our Vespa family
we were beguiled by tempting opportunities into
running after the solitary wasps. The solitaries, so far as
species are concerned, are immensely more numerous
than the socials ; but they have only two sexes, and the
males and females usually see but little of each other
after the mating is over, although we occasionally find
them living happily together until the end of the season.
In the early summer they begin to emerge from the nest
in which the eggs were laid the year before. Solitary in-
deed they come into the world, the generation that gave
them birth having perished in the fall. For a time their
career is one of unmixed pleasure, and yet, free and un-
guided though they are, basking in the sunshine, feeding
on the flowers, or sleeping at night under some sheltering
leaf, they are hourly acquiring experience, so that when
the cares of life descend upon them they are no longer
creatures of mere instinct. With these sobering cares an

WASPS, SOCIAL AND SOLITARY

almost absurdly heavy sense of responsibility for future
generations transforms the hitherto happy-go-lucky fe-
males into grown-up wasps with serious views on market-
ing and infant foods. Each one makes a separate nest
and provisions it by her own labor ; and in many cases a
new nest is made for each egg. There is no cooperation
among them ; although in certain genera, as Aphilan-
thops and Bembex, a number of individuals build close
together, forming a colony. The nests may be made of
mud, and attached for shelter under leaves, rocks, or
eaves of buildings, or may be burrows hollowed out in
the ground, in trees or in the stems of plants. The adult
wasp lives upon fruit or nectar, but the young grub or
larva must have animal food ; and here the parent wasp
shows a rigid conservatism, each species providing the
sort of food that has been approved by its family for
generations, one taking flies, another bugs, and another
beetles, caterpillars, grasshoppers, crickets, locusts,
spiders, cockroaches, aphides, or other creatures, as the
case may be.

When the egg-laying time arrives the female secures
her prey, which she either kills or paralyzes, places it in
the nest, lays the egg upon it, and then, in most cases,
closes the hole and takes no further interest in it, going on
to make new nests from day to day. In some genera the

AMMOPHILA AND HER CATERPILLARS

female maintains a longer connection with her offspring,
not bringing all the provision at once, but returning to
feed the larva as it grows, and leaving the nest perma-
nently only when the grub has spun its cocoon. The
males never acquire this interest, so admirable for the
development of character, and aid little, if at all, in
the care of the family. The egg develops in from one to
three days into a footless, maggot-like creature which
feeds upon the store provided for it, increasing rapidly
in size, and entering the pupal stage in from three days
to two weeks. In the cocoon it passes through its final
metamorphosis, emerging as a perfect insect, perhaps in
two or three weeks, or, in many cases, after the winter
months have passed and summer has come again.

Most graceful and attractive of all the wasps — " taille
effilee, tournure svelte," as Fabre describes them, the Am-
mophiles, of all the inhabitants of the garden, hold the
first place in our affections. Not so beautiful as the blue
Pelopaeus, nor so industrious as the little red-girdled Try-
poxylon, their intelligence, their distinct individuality,
and their obliging tolerance of our society make them
an unfailing source of interest. They are, moreover, the
most remarkable of all genera in their stinging habits,
being supposed to use the nicest surgical skill in para-
lyzing their caterpillars ; and few things have given us

WASPS, SOCIAL AND SOLITARY

deeper pleasure than our success in following the ac-
tivities and penetrating the secrets of their lives. In our
garden we have two species of Ammophila, urnaria C res-
son, and gracilis Cresson, both of them being very slender-
bodied wasps of about an inch in length, gracilis all black,
and urnaria with a red band around the front end of the
abdomen. A. polita and A. vulgaris, which look much
like urnaria, are common in the sandy fields west and
south of Milwaukee.

During the earlier part of the summer we had often
seen these wasps feeding upon the nectar of flowers,
especially upon that of the sorrel, of which they are par-
ticularly fond ; but at that time we gave them but pass-
ing notice. One bright morning, however, we came upon
an urnaria that was so evidently hunting, and hunting in
earnest, that we gave up everything else to follow her.
The ground was covered, more or less thickly, with
patches of purslain, and it was under these weeds that our
Ammophila was eagerly searching for her prey. After
thoroughly investigating one plant she would pass to an-
other, running three or four steps and then bounding as
though she were made of thistledown and were too light to
remain upon the ground. We followed her easily, and as
she was in full view nearly all of the time we had every
hope of witnessing the capture ; but in this we were des-

AMMOPHILA AND HER CATERPILLARS

tined to disappointment. We had been in attendance on
her for about a quarter of an hour when, after disappear-
ing for a few moments under the thick purslain leaves,
she came out with a green caterpillar. We had missed the
wonderful sight of the paralyzer at work ; but we had no
time to bemoan our loss, for she was making off at so

AMMOPHILA URNARIA CARRYING CATERPILLAR TO NEST

rapid a pace that we were well occupied in keeping up
with her. She hurried along with the same motion as
before, unembarrassed by the weight of her victim. For
sixty feet she kept to open ground, passing between two
rows of bushes ; but at the end of this division of the gar-
den, she plunged, very much to our dismay, into a field

WASPS, SOCIAL AND SOLITARY

of standing corn. Here we had great difficulty in follow-
ing her, since, far from keeping to her former orderly
course, she zigzagged among the plants in the most be-
wildering fashion, although keeping a general direction
of northeast. It seemed quite impossible that she could
know where she was going. The corn rose to a height of
six feet all around us ; the ground was uniform in appear-
ance, and, to our eyes, each group of cornstalks was just
like every other group, and yet, without pause or hesita-
tion, the little creature passed quickly along, as we might
through the familiar streets of our native town.

At last she paused and laid her burden down. Ah ! the
power that has led her is not a blind, mechanically per-
fect instinct, for she has traveled a little too far. She
must go back one row into the open space that she has
already crossed, although not just at this point. Nothing
like a nest is visible to us ; the surface of the ground looks
all alike, and it is with exclamations of wonder that we
see our little guide lift two pellets of earth which have
served as a covering to a small opening running down
into the ground.

The way being thus prepared, she hurries back with
her wings quivering and her whole manner betokening
joyful triumph at the completion of her task. We, in
the mean time, have become as much excited over the

AMMOPHILA AND HER CATERPILLARS

matter as she is herself. She picks up the caterpillar,
brings it to the mouth of the burrow, and lays it down.
Then, backing in herself, she catches it in her mandi-
bles and drags it out of sight, leaving us full of admira-
tion and delight.

How clear and accurate must be the observing powers
of these wonderful little creatures ! Every patch of ground
must, for them, have its own character ; a pebble here,
a larger stone there, a trifling tuft of grass - - these must
be their landmarks. And the wonder of it is that their
interest in each nest is so temporary. A burrow is dug,
provisioned and closed up, all in two or three days, and
then another is made in a new place with everything to
learn over again.

From this time on to the first of September our garden
was full of these wasps, and they never lost their fasci-
nation for us ; although, owing to a decided difference be-
tween their taste and ours as to what constituted pleasant
weather, all our knowledge of them was gained by the
sweat of our brows. When we wished to utilize the cool
hours of the morning or of the late afternoon in studying
them, or thought to take advantage of a cloud which cast
a grateful shade over the sun at noonday, where were
our Ammophiles ? Out of sight entirely, or at best only
to be seen idling about on the flowers of the onion or

WASPS, SOCIAL AND SOLITARY

sorrel. At such a time they seemed to have no mission
in life and no idea of duty. But when the air was clear
and bright and the mercury rose higher and higher, all
was changed. Their favorite working hours were from
eleven in the morning to three in the afternoon, and
when they did work they threw their whole souls into it.
It was well that it was so, for they certainly needed all
the enthusiasm and perseverance that they could muster
for such wearisome and disappointing labor. Hour after
hour was passed in search, and often there was nothing
to show at the end of it. Urnaria hunted on bare ground,
on the purslain, and most of all on the bean-plants.
These were examined carefully, the wasp going up and
down the stems and looking under every leaf ; but the
search was so frequently unsuccessful that in estimating
their work we are inclined to think that they can scarcely
average one caterpillar a day.

In this species, as in every one that we have studied,
we have found a most interesting variation among the
different individuals, not only in methods, but in char-
acter and intellect. While one was beguiled from her
hunting by every sorrel blossom she passed, another
stuck to her work with indefatigable perseverance. While
one stung her caterpillar so carelessly and made her nest
in so shiftless a way that her young could survive only

AMMOPHILA AND HER CATERPILLARS

through some lucky chance, another devoted herself to
these duties not only with conscientious thoroughness,
but with an apparent craving after artistic perfection
that was touching to see.

The method employed by the Ammophiles in stinging
their prey is more complex than that of any other preda-
tory wasp. The larvae with which they provision their
nests are made up of thirteen segments, and each of
these has its own nervous centre or ganglion. Hence if
the caterpillar is to be reduced to a state of immobility,
or to a state so nearly approaching immobility that the
egg may be safely laid upon it, a single sting, such as
is given by some of the Pompilidae to their captured
spiders, will be scarcely sufficient. All this we knew from
Fabre's "Souvenirs," and yet we were not at all pre-
pared to believe that any plain American wasp could
supply us with such a thrilling performance as that of
the Gallic hirsuta, which he so dramatically describes.
We were, however, most anxious to be present at the all-
important moment that we might see for ourselves just
how and where urnaria stings her victim.

For a whole week of scorching summer weather we
lived in the bean patch, scorning fatigue. We quoted to
each other the example of Fabre's daughter Claire, who
followed Odynerus with unfaltering zeal until a sun-

WASPS, SOCIAL AND SOLITARY

stroke laid her low. We attended scores of wasps as they
hunted; we ran, we threw ourselves upon the ground,
we scrambled along on our hands and knees in our des-
perate endeavors to keep them in view, sometimes with
our eyes upon the wasps themselves and sometimes pur-
suing their shadows, which, like those of coming events,
were cast before ; and yet they escaped us. After we had
kept one in sight for an hour or more, some sudden flight
would carry her far away, and all our labor was lost.

At last, however, our day came. We were doing a
little hunting on our own account, hoping to find some
larvae which we could drop in view of the wasps and thus
lead them to display their powers, when we saw an
urnaria fly up from the ground to the underside of a
bean leaf and knock down a small green caterpillar.
Breathless with an excitement which will be understood
by those who have tasted the joy of such a moment, we
hung over the actors in our little drama. The ground
was bare, we were close by and could see every motion
distinctly. Nothing more perfect could have been
desired.

The wasp attacked at once, but was rudely repulsed,
the caterpillar rolling and unrolling itself rapidly and
with the most violent contortions of the whole body.
Again and again its adversary descended, but failed to

AMMOPHILA AND HER CATERPILLARS

gain a hold. The caterpillar, in its struggles, flung itself
here and there over the ground, and had there been any
grass or other covering near by it might have reached a
place of partial safety; but there was no shelter within
reach, and at the fifth attack the wasp succeeded in
alighting over it, near the anterior end, and in grasping
its body firmly in her mandibles. Standing high on her
long legs and disregarding the continued struggles of her
victim, she lifted it from the ground, curved the end of
her abdomen under its body, and darted her sting be-
tween the third and fourth segments. From this instant
there was a complete cessation of movement on the part
of the unfortunate caterpillar. Limp and helpless, it
could offer no further opposition to the will of its con-
queror. For some moments the wasp remained motion-
less, and then, withdrawing her sting, she plunged it
successively between the third and the second, and
between the second and the first segments.

The caterpillar was now left lying on the ground. For
a moment the wasp circled above it, and then, descend-
ing, seized it again, further back this time, and with
great deliberation and nicety of action gave it four more
stings, beginning between the ninth and tenth segments
and progressing backward.

Urnaria, probably feeling - - as we certainly did - - a

WASPS, SOCIAL AND SOLITARY

reaction from the strain of the last few minutes, and a
relief at the completion of her task, now rested from her
labors. Alighting on the ground close by, she proceeded
to smooth her body with her long hind legs, standing, in
the mean time, almost on her head, with her abdomen
directed upward. She then gave her face a thorough
washing and rubbing with her first legs, and not until
she had made a complete and satisfactory toilet did she
return to the caterpillar.

We saw Ammophila capture her prey only three times
during the whole summer; but from these observations
and from the condition of her caterpillars taken at vari-
ous times from nests, her method seems to be wonder-
fully close to that of hirsuta, with just about the same
amount of variation in different individuals.

Thus in our second example, she stung the first three
segments in the regular order, the third, the second, and
lastly (and most persistently) the first. She then went on,
without a pause, to sting the fourth, fifth, sixth, and
seventh, stopping at this point and leaving the posterior
segments untouched. In our first example, it will be
remembered, the middle segments were spared. The
stinging being completed, she proceeded to the process
known as malaxation, which consists in repeatedly
squeezing the neck of the caterpillar, or other victim,

AMMOPHILA AND HER CATERPILLARS

between the mandibles, the subject of the treatment
being turned around and around so that all sides may be
equally affected.

In our third case a caterpillar which we had caught
was placed in front of a wasp just after she had carried
the second larva into her nest. She seemed rather indif-
ferent to it, passing it once or twice as she ran about, but
finally picked it up and gave it one prolonged sting be-
tween the third and fourth segments. She then spent a

AMMOPHILA URNARIA STINGING CATERPILLAR

long time in squeezing the neck, pinching it again and
again, after which it was left on the ground ; and as she
showed no further interest in it we carried it home for
further study.

WASPS, SOCIAL AND SOLITARY

In the three captures, then, that came under our ob-
servation, all the caterpillars being of the same species
and almost exactly of the same size, three different
methods were employed. In the first, seven stings were
given at the extremities, the middle segments being left
untouched, and no malaxation was practiced. In the
second, seven stings again, but given in the anterior and
middle segments, followed by slight malaxation. In the
third, only one sting was given, but the malaxation was
prolonged and severe.

Let us now compare these variations with those of
Fabre. In his first case the sting entered at twelve dif-
ferent points, beginning between the first and second
segments and progressing regularly backward. There
was no malaxation. In his second example the third,
second, and first segments were stung in the order given,
and thereafter each succeeding segment up to the ninth,
nine stings being given in all, with careful malaxation
following. In his later experiments, which seem to have
been numerous, he found that as a usual thing all the
segments were stung, although the posterior three or
four were occasionally spared, but that the order in
which they were operated upon, as well as the amount
of malaxation, was very variable.

Our conclusions, then, as to Ammophila's methods of

AMMOPHILA AND HER CATERPILLARS

stinging agree fairly well with those of Fabre ; but there
is one important exception. In his cases the middle seg-
ments, upon one of which the egg is laid in our species
as well as in his, were in-
variably stung, and this he
considers a point of extreme
importance. In one of our
cases the middle segments

Were not touched. CATERPILLAR WITH EGG OF

AMMOPHILA URNARIA

The point in which our

observations differ most widely from those of Fabre is
in the condition of the caterpillars after the stinging.
He seems to have found that they always lived a long
time, but in a motionless or nearly motionless state ;
and he dwells at length upon the necessity of both of
these conditions, since he believes that while the wasp
larva must have perfectly fresh food, any violent mo-
tion would imperil its safety. As a matter of fact we
found a wide variation in the thoroughness with which
the wasps performed their task. We had, in all, fifteen
caterpillars upon which urnaria had worked her will ;
and while a few of them fulfilled to a nicety the con-
ditions which Fabre believes to be imperative, most of
them were far from doing so. Some of them lived only
three days, others a little longer, while still others showed

WASPS, SOCIAL AND SOLITARY

signs of life at the end of two weeks. Urnaria stores
two caterpillars, and in more than one instance the
second one died and became discolored before the first
one was entirely eaten. The wasp larva did not, as
might have been expected, find fault with this arrange-
ment, but proceeded to attack number two with good
appetite, ate it all up, and then spun its cocoon as
though nothing unpleasant had occurred.

The second condition was also violated. In one case
the bite of the newly hatched larva caused the caterpillar
to rear upon end in so violent a manner that it looked as
though the little creature would surely be dislodged.
Another caterpillar kept up a continuous wriggling with-
out any external stimulation, and when it was touched it

rolled about almost as these larvae do in a healthy state,

•

and yet the egg was not shaken off. The caterpillar
which received but a single sting, although not motion-
less, would have been a safer repository for the egg than
either of these. Others fulfilled Fabre's condition per-
fectly, lying immovable except when stimulated, and then
responding only by a slight quivering of the legs or skin.
Among the fifteen caterpillars that we have taken
from the nests of urnaria three kinds are represented,
twelve of them belonging to one species, two to the sec-
ond, and one to the third.

AMMOPHILA AND HER CATERPILLARS

The egg, which is laid upon the side of the sixth or
seventh segment, hatches in from two to three days; the
larva spends from six days to two weeks in eating, and
then spins its pale yellowish cocoon.

The nesting habits of urnaria closely resemble those
of the other members of the genus, as reported by vari-
ous observers. The spot chosen is in firm soil, sometimes
in open ground, but much more frequently under the
leaves of some plant. The plan is a very simple one.

NEST OF AMMOPHILA

A tunnel of about an inch in length leads to the pocket
in which the caterpillars are stored. There is no harden-
ing of the walls in any part. We took pains to draw
every nest that we opened, and there was a very con-
siderable variation in the minor details, such as the ob-
liquity of the entrance tunnel, the shape of the pocket,

WASPS, SOCIAL AND SOLITARY

and the angle at which the tunnel and pocket were
joined.

The work is done with the mandibles and the first
legs. When it has proceeded so far that the wasp is partly
hidden, she begins to carry the earth away from the nest.
In doing this she backs up to the edge of the opening and,
flying a little way, gives a sort of flirt which throws the
pellet that she carries in her mandibles to a distance.
She then alights where she is and pauses a moment be-
fore she runs back to the hole, or, in some cases, darts
back on the wing. We watched the process of nest-mak-
ing five times during the summer. In the first instance
Ammophila, having made her excavation, ran off and
after some search returned with a good- sized lump of
earth. This she laid over the opening, which was now
entirely hidden. She then flew to the bean patch close
by, but after ten minutes she came back and looked at
her nest. It was so neatly covered as to be almost indis-
tinguishable, but to this fastidious little creature some-
thing seemed lacking. She pulled away the cover, car-
ried out three or four more loads, and then began to
search for another piece for closing. After a time she
came hurrying back with a lump of earth, but when
close to the nest she concluded that it would not do,
dropped it, and ran off in another direction. Presently

AMMOPHILA AND HER CATERPILLARS

she found one which fitted into the hole exactly, and
after placing it she brought a much smaller piece which
she put above and to one side. She then stood back
and surveyed the whole, and it seemed to us that we
could read pride and satisfaction in her mien. She then
flew away, and we supposed that that stage of the work
was completed. Upon coming back two hours later,
however, we found that she had been trying some more
improvements, as a number of little pellets had been
piled up over the nest. This wasp, by the way, never
succeeded in finding a caterpillar, since when we opened
the burrow a few days later it was still empty. Perhaps
she came to some untimely end.

Of the other wasps that we saw making a temporary
closure of their nests, one wedged a good-sized stone
deep down into the neck of the burrow and then filled
the space above, solidly, with smaller stones and earth.
Another placed two lumps of earth just below the sur-
face of the ground, filled the opening with pellets loosely
thrown in, and then kicked some light dust over the
whole. The others used only two or three lumps of earth,
which they fitted neatly into the opening just below the
surface. Although it is usual for urnaria to leave her
nest closed while she is off searching for her prey, there
is no invariable rule in the matter, even for single individ-

WASPS, SOCIAL AND SOLITARY

uals. Once having seen a wasp dig her nest and close it
up, we drew some radiating lines from the spot, in the
light dust that covered the place, that we might find it
again. When we returned, two hours later, the same
wasp had made a nest four or five inches distant from the
first one, and had left it wide open, while she had gone
off to search for her caterpillar. She had probably been
alarmed by the marks that we had made, and had felt
it necessary to dig a new nest, but being in a hurry to
lay her egg had omitted the usual process of closing it.
We witnessed the storing of the caterpillar and the final
closing.

From Fabre we learn that argentata and sabulosa
close the nest as soon as it has been made, at least when
the provisioning is to be postponed until the next day,
while holosericea leaves it open until it is completely
stored. He suggests an explanation for this variation
by dwelling upon the inconvenience that would result if
it were opened every time that the wasp brought in a
caterpillar, since holosericea stores up five or six small
larvae instead of one or two large ones. But what, then,
shall be said of polita and yarrowii, which, while they
also store a number of small caterpillars, take pains to
close and conceal the entrance every time they come
out? We see the same habit in other genera where the

AMMOPHILA AND HER CATERPILLARS

mother continually passes in and out, as in Bembex
and Oxybelus.

Fabre thinks that hirsuta has the habit, unusual for
Ammophila, of catching her prey first and then digging
the hole in which she bestows it. As she takes only one
large caterpillar she is thus relieved of the necessity of
closing the nest more than once.

As has been said, urnaria usually hunts a long time
before she finds her caterpillar, and one or two days
may pass before anything is put into the nest. During
this prolonged search she often revisits the spot, and
thus keeps fresh the memory of its locality. As soon as
the first caterpillar is stored she lays an egg on it, and
then closes the nest as before. The second one may be
brought in within a few hours ; but in one instance that
came under our notice we feel sure that the interval
was as much as three days. We saw the interment of the
second caterpillar, and upon excavating, found on the
first one a larva at least a day old; we suppose that at
least two days had elapsed between the laying and the
hatching of the egg.

When the provisioning is completed the time arrives
for the final closing of the nest ; and in this, as in all the
processes of Ammophila, the character of the work dif-
fers with the individual. For example, of two wasps that

WASPS, SOCIAL AND SOLITARY

we saw close their nests on the same day, one wedged
two or three pellets into the top of the hole, kicked in a
little dust, and then smoothed the surface over, finishing
it all within five minutes. This one seemed possessed
by a spirit of hurry and bustle, and did not believe in
spending time on non-essentials. The other, on the con-
trary, was an artist, an idealist. She worked for an hour,
first filling the neck of the burrow with fine earth which
was jammed down with much energy, — this part of the
work being accompanied by a loud and cheerful hum-
ming, — and next arranging the surface of the ground
with scrupulous care, and sweeping every particle of
dust to a distance. Even then she was not satisfied, but
went scampering around, hunting for some fitting object
to crown the whole. First she tried to drag a withered
leaf to the spot, but the long stem stuck in the ground
and embarrassed her. Relinquishing this, she ran along
a branch of the plant under which she was working and,
leaning over, picked up from the ground below a good-
sized stone ; but the effort was too much for her, and she
turned a somersault on to the ground. She then started
to bring a large lump of earth ; but this evidently did not
come up to her ideal, for she dropped it after a moment,
and seizing another dry leaf carried it successfully to
the spot and placed it directly over the nest. A third

AMMOPHILA AND HER CATERPILLARS

instance of the final closing of the nest was interme-
diate between these two, the work occupying twenty
minutes. The wasp first put a plug well down, then
dropped in several large pellets, brushed in a quantity
of fine earth, and finally smoothed the surface over.

We had another much less worthy example, one, in-
deed, that went to the extreme of carelessness. We first
saw her in the morning carrying her caterpillar across
the field. She frequently dropped it and ran or flew to a
little distance, and when she took it again the venter
was sometimes up and sometimes down, whichever
way it happened. Her nest was a very poor affair just
beneath the surface, and after the caterpillar was carried
in, it was visible from above. She filled the hole with
loose particles of earth and then scratched the surface
of the ground a little in a perfunctory sort of way, as
different as possible from the painstaking labor that
we had been accustomed to in her sisters. That afternoon
we opened the nest and removed its contents. The next
morning we saw this wasp bringing home her second
caterpillar. She was much puzzled and disturbed at the
destruction of her nest, and hunted for it for an hour
and a half, leaving the caterpillar on the ground near
by. We could not help feeling sorry that we had inter-
rupted the contented routine of her life. She finally gave

WASPS, SOCIAL AND SOLITARY

up in despair, and we took possession of the deserted
caterpillar.

Just here must be told the story of one little wasp
whose individuality stands out in our minds more dis-
tinctly than that of any of the others. We remember
her as the most fastidious and perfect little worker of
the whole season, so nice was she in her adaptation of
means to ends, so busy and contented in her labor of
love, and so pretty in her pride over the completed work.
In filling up her nest she put her head down into it and
bit away the loose earth from the sides, letting it fall to
the bottom of the burrow, and then, after a quantity
had accumulated, jammed it down with her head. Earth
was then brought from the outside and pressed in, and
then more was bitten from the sides. When, at last, the
filling was level with the ground, she brought a quantity
of fine grains of dirt to the spot, and picking up a small
pebble in her mandibles, used as it a hammer in pound-
ing them down with rapid strokes, thus making this
spot as hard and firm as the surrounding surface. Be-
fore we could recover from our astonishment at this
performance she had dropped her stone and was bring-
ing more earth. We then threw ourselves down on the
ground that not a motion might be lost, and in a mo-
ment we saw7 her pick up the pebble and again pound

AMMOPHILA AND HER CATERPILLARS

the earth into place with it, hammering now here and
now there until all was level. Once more the whole pro-
cess was repeated, and then the little creature, all un-
conscious of the commotion that she had aroused in

AMMOPHILA URNARIA USING STONE TO POUND DOWN EARTH

OVER NEST

our minds, - - unconscious, indeed, of our very existence
and intent only on doing her work and doing it well, — •
gave one final, comprehensive glance around and flew
away.

We are claiming a great deal for Ammophila when we
say that she improvised a tool and made intelligent use

WASPS, SOCIAL AND SOLITARY

of it, for such actions are rare even among the higher
animals; but fortunately our observation does not stand
alone, although we supposed this to be the case at the
time that it was made. Some weeks later, seeing a note
of a similar occurrence by Dr. S. W. Williston, of Kansas
University, we wrote to him on the subject. In his reply
he said that he had waited for a year before venturing
to publish his observation, fearing that so remarkable a
statement would not be credited. His account is so in-
teresting that we quote it at length.

Even the casual observer, to whom all insects are bugs,
cannot help but be struck by the great diversity and
number of the fossorial Hymenoptera of the plains. Water
is often inaccessible, trees there are few or none, and only
in places is the vegetation at all abundant. A much larger
proportion of insects, hence, find it necessary to live or
breed in holes in the ground, than is the case in more
favored localities. Especially is this the case with the
Hymenoptera, great numbers and many species of which
thus breed in excavations made by themselves.

While packing specimens on an open space, uncovered
by buffalo grass, in the extreme western part of Kansas,
the early part of last July, the attention of a friend and
myself was attracted by the numerous wasps that were
constantly alighting upon the ground. The hard, smooth
baked surface showed no indications of disturbance, and
it was not till we had attentively watched the insects that

AMMOPHILA AND HER CATERPILLARS

we learned what they were doing. The wasp is a very
slender one, more than an inch in length, with a slender,
pedicellate abdomen ; it is known to entomologists as
Ammophila yarrowii Cres. They were so numerous that
one was distracted by their very multiplicity, but, by
singling out different individuals, we were enabled to verify
each detail of their operations. An insect, alighting, ran
about on the smooth, hard surface till it had found a suit-
able spot to begin its excavation, which was made about a
quarter of an inch in diameter, nearly vertical, and carried
to a depth of about four inches, as was shown by opening
a number of them. The earth, as removed, was formed
into a rounded pellet and carefully carried to the neighbor-
ing grass and dropped. For the first half of an inch or so
the hole was made of a slightly greater diameter. When
the excavation had been carried to the required depth, the
wasp, after a survey of the premises, flying away, soon
returned with a large pebble in its mandibles, which it
carefully deposited within the opening; then, standing
over the entrance upon her four posterior feet, she (I say
she, for it was evident that they were all females) rapidly
and most amusingly scraped the dust with her two front
feet, "hand over hand," back beneath her, till she had
filled the hole above the stone to the top. The operation
so far was remarkable enough, but the next procedure was
more so. When she had heaped up the dirt to her satis-
faction, she again flew away and immediately returned
with a smaller pebble, perhaps an eighth of an inch in
diameter, and then standing more nearly erect, with the

WASPS, SOCIAL AND SOLITARY

front feet folded beneath her, she pressed down the dust
all over and about the opening, smoothing off the surface,
and accompanying the action with a peculiar rasping
sound. After all this was done, and she spent several
minutes each time in thus stamping the earth so that only
a keen eye could detect any abrasion of the surface, she
laid aside the little pebble and flew away to be gone some
minutes. Soon, however, she comes back with a heavy
flight, scarcely able to sustain the soft green larva, as long
as herself, that she brings. The larva is laid upon the
ground, a little to one side, when, going to the spot where
she had industriously labored, by a few, rapid strokes she
throws out the dust and withdraws the stone cover, laying
it aside. Next, the larva is dragged down the hole, where
the wasp remains for a few minutes, afterwards returning
and closing up the entrance precisely as before. This, we
thought, was the end, and supposed that the wasp would
now be off about her other affairs, but not so ; soon she
returns with another larva, precisely like the first, and the
whole operation is again repeated. And not only the
second time, but again and again, till four or five of the
larvae have been stored up for the sustainment of her future
offspring. Once, while a wasp had gone down the hole
with a larva, my friend quietly removed the door stone that
she had placed by the entrance. Returning, she looked
about for her door, but not finding it, apparently mistrusted
the honesty of a neighbor, which had just descended,
leaving her own door temptingly near. She purloined
this pebble and was making off with it, when the rightful

AMMOPHILA AND HER CATERPILLARS

owner appeared and gave chase, compelling her to relin-
quish it.

The things that struck us as most remarkable were the
unerring judgment in the selection of a pebble of precisely
the right size to fit the entrance, and the use of the small
pebble in smoothing down and packing the soil over the
opening, together with the instinct that taught them to
remove every evidence that the earth had been dis-
turbed.

Since the Ammophiles of our species make their nests
first and then do their hunting it follows that they must
sometimes carry their prey for a considerable distance.
The most ambitious attempt of this kind that we ever
witnessed was made by gracilis.

The wasp was first seen carrying a large green cater-
pillar, which projected at both ends beyond her own
body, across the potato field at the lower end of the gar-
den. We could not tell how far she had already brought
it, but judging by the direction from which she was
coming, and by the fact that we had never seen that
species of caterpillar in the garden, she had probably
come through the fence from the woods beyond. She
moved along briskly over the remaining part of the
potato field, and then through an adjoining bean patch
into the corn field. This had been a place of much anx-
iety to us earlier in the summer ; but now the corn had

WASPS, SOCIAL AND SOLITARY

been stacked and we could follow her without difficulty.
So far she had been going due south ; but now she made
a turn and plunged into the long, tangled grass which
grew around and among some large, overgrown rasp-
berry bushes. To keep track of her here seemed a hope-
less task, but we resolved to do our best, and followed
anxiously after. The wasp worked her way along about
two inches above the ground and very much below the
top of the grass, clinging to the blades with her feet and
making surprisingly good progress. When half way
through the raspberry bushes she carried the caterpillar
up on to a branch, deposited it there, and after circling
about to take her bearings, flew away, doubtless to visit
her nest and to make sure that she was going in the right
direction.

We, ourselves, were very glad of the chance to rest our
tired eyes and nerves from the strain of following her.
The journey, so far, had occupied nearly an hour, at
almost every instant of which it had been exceedingly
difficult to keep her in view. But for our united efforts
we should certainly have failed.

While standing guard over the caterpillar we noticed
that it moved its head from side to side, showing that the
first segment could not have been severely stung, as is
usually the case in the work of urnaria.

AMMOPHILA AND HER CATERPILLARS

In five minutes the wasp returned, and, with the air of
feeling that everything was right, picked up her burden
and carried it laboriously through the remaining bushes
and then through the grassy space that edged the garden,
as far as the rail fence which separated this part of the
grounds from the woods. Without a pause she climbed
on to this fence to the height of the second rail, passed
through, and flew down on the further side. Here she
paused a moment, perhaps to take breath, and we
looked at each other in some dismay. Whither was she
leading us ? We had now been following her for over an
hour, and she looked equal to as much again as she
started off once more, rapidly this time, for the grass was
short here and the traveling was easy. Soon, however, it
became evident that things were going wrong, although
we could not determine what was the matter. The cater-
pillar was laid down while the wasp absented herself for
six minutes. She returned and carried it for fifteen min-
utes, and then left it for half an hour. Once more she
came back, and carried it for ten minutes, and then she
flew away. It was now four o'clock, and we had been
following her since two. We watched over the caterpillar
for an hour longer, but saw no more of the wasp.

Did she become discouraged at the magnitude of her
task? It would have been a thousand times easier for

WASPS, SOCIAL AND SOLITARY

her to have dug her nest close by the place of capture,
but perhaps she had one larva already stored with her
egg upon it. The caterpillar was carried two hundred
and sixty-one feet while we watched her, with an un-
known distance at each end to complete the line between
the place of capture and the nest. She could scarcely
have lost her way, since at every return she proceeded on
her journey in one general direction without any hesita-
tion. It seems probable then that she had hunted too
far afield, and did not realize, when she started with her
booty, what an undertaking it would be to carry it to the
nest. We once saw A. vulgaris have a similar experience.
She was running along with a small green caterpillar,
but became discouraged either at the difficulty of finding
her nest, or at the distance she had to cover. She would
carry the caterpillar a little way, drop it, circle about
a while, and then pick it up again ; but finally she gave
up the whole undertaking and flew away.

The affairs of Ammophila must frequently go wrong,
since in still another of our few examples we saw much
trouble and labor wasted. The wasp, in this case an
urnaria, captured her caterpillar successfully and pro-
ceeded to carry it off. She was far from being in a hurry,
going along for a foot or so, and then making a long
pause, during which she would lay it down and either

AMMOPHILA AND HER CATERPILLARS

circle above it, perhaps to take bearings, or spend the
time in cleaning herself off, stroking and smoothing
every part of her body with the utmost care and deliber-
ation. Her stops were so frequent and so lengthy that
nearly an hour was occupied in going about twenty-five
feet. When, at last, the nest was reached, the plug was
removed from the entrance and the caterpillar dragged
in, but almost immediately the wasp came out back-
wards with the point of an egg projecting from the ex-
tremity of her abdomen. She ran around and around the
nest in a distracted way four or five times and then went
back, dragged the caterpillar out, and carried it away.
The egg came out further and further, and finally
dropped on the ground and was lost. The wasp, carry-
ing the caterpillar, led us a long dance, in a great semi-
circle over the field, coming back to the nest at last.
Instead of going in, however, she was about to start off
on another tour when we took her prey from her and
placed it in the nest. The wasp remained in the neigh-
borhood for over an hour, but finally disappeared. The
nest was not closed, and when we dug it up on the fol-
lowing day it contained only the caterpillar that we had
put in.

We could usually enter into the feelings of the Ammo-
philes and understand the meaning of their actions ; but

WASPS, SOCIAL AND SOLITARY

we were puzzled once, when we saw an urnaria that had
stored her second caterpillar and closed her nest perma-
nently, spend the rest of her morning in hunting. Why
in hunting? She had not dug a nest, she could not lay
another egg at once, she did not want a caterpillar, for
when we offered her one she stung it and then left it lying
on the ground. The sun was bright, the sorrel-blossoms
invited her. Surely it would have been the part of a ra-
tional wasp to have passed the rest of the day in feasting
and fun.

We have said that urnaria stores two caterpillars, but
this rule is not without its exception. It was on the last
day of the summer that on a visit to our dear and fruit-
ful potato field, we came upon a wasp of almost double
the ordinary size, that made, when flying, a loud hum
that at once attracted attention. She was just complet-
ing and closing her nest, and we determined to watch
and see what kind of a victim she would bring in, as
it seemed improbable that this great creature would
content herself with the ordinary fare of the species.
The opening to the nest measured half an inch in dia-
meter.

It was eleven o'clock when she flew away. At half past
twelve she reappeared, coming from the direction of the
woods, opened her nest, and took out a few more pellets.

AMMOPHILA AND HER CATERPILLARS

Then she flew to a bush which grew against the fence,
three feet away, and following her quickly we saw an
immense green caterpillar placed high up on a branch.
It must have taken both strength and perseverance to
lift this heavy weight so far from the ground. She seized
it at once and carried it down, not flying, as these wasps
sometimes do when they are descending with a burden,
and then dragged it into her nest, where it fitted rather
tightly. This nest was so shallow and so obliquely di-
rected that the caterpillar was plainly visible after it had
been taken in.

After she had laid her egg she crawled out, getting
past the caterpillar with some difficulty, and closed the
nest. There was certainly no room for any further store
of provisions, and from the size of the caterpillar we
judged that it would furnish sufficient nourishment even
for the offspring of this wasp. We were, therefore, not
surprised, upon opening the nest two days later, to find
that nothing more had been brought. We have said that
the wasp larvae spend from six days to two weeks in eat-
ing. To be more exact, all that we watched, with the
exception of the one which developed from the egg of
this big creature, ate from six to eight days and then
spun their cocoons ; but this one seemed determined to
reach the size of its mother, and ate continuously for

WASPS, SOCIAL AND SOLITARY

fourteen days. Of course long before this time had ex-
pired the remnant of the caterpillar had become a dry,
dark- colored mass which looked little likely to tempt the
appetite, but the great larva ate away with unabated
relish, gradually acquiring the color and almost the
thickness of the caterpillar it had destroyed.

Ammophila polita, which we have never seen in the
country, is very common in the sandy fields to the south
of Milwaukee. On the tenth of September, in bright
clear weather, we found half a dozen individuals work-
ing within a few rods of each other, their method being
similar to that of A. yarrowii, described by Dr. Willis-
ton, and having an especial interest, as it shows a transi-
tion stage between the wasps that provide the store of
food all at once and those that feed their young all
through the larval period. Urnaria rarely flies with her
prey ; but this wasp, although her caterpillars, are not
very much smaller, and she herself is no larger, carries
her booty lightly on the wing, alighting only occasion-
ally to run a few steps. She has to do more work than
urnaria, taking five or six caterpillars instead of two,
and this method of progression has the advantage of
rapidity.

The first wasp that we saw was just alighting with a
medium-sized green caterpillar near a partly closed

AMMOPHILA AND HER CATERPILLARS

nest. When disturbed she flew away, but soon returned,
dropped her prey half an inch from the nest, proceeded
to clear the opening, ran inside to see that all was right,
and then backed in with the caterpillar. Emerging after
a few minutes, she placed a small pebble in the doorway,
which was thus partly closed, and flew away. She
brought three more caterpillars at intervals of thirty
minutes, and then, after wedging a pebble into the neck
of the opening, she began to fill it in solidly, scratching
in dirt and packing in lumps of earth which were brought
in her mandibles. We did not allow her to complete
this operation, as it would have made excavation more
difficult, but caught her and dug out the nest. The
tunnel ran down obliquely for five inches, being two
inches below the surface at the pocket. In it we found
a wasp larva, which was at least three days old, and
four caterpillars. There were no signs of the banquet-
ing which must have already taken place. We carried
this larva home with us, and it ate the caterpillars up
clean, finishing with a fifth which we supplied from
another nest, and going into its cocoon on September
sixteenth. The caterpillars all wriggled about on the
slightest stimulation, and remained in this lively state
until they were eaten. They belonged to four different
species.

WASPS, SOCIAL AND SOLITARY

In a second nest to which food was being carried, we
found four caterpillars and a larva about three days
old, all the conditions being like those in the other ex-
ample. Evidently the larva had been fed from day to
day, since four or five days must have elapsed since the
making of the nest.

Westwood states that Ammophila, when she has cap-
tured her prey, walks backward, dragging it after her;1
but in all the cases that came under our notice she went
forward, the caterpillar being grasped near the anterior
end, in her mandibles, and either lifted above the ground
or allowed to drag a little if long and heavy. It is usually
held venter up, but in one case, in which the wasp,
while carrying it to her nest, frequently laid it down
and picked it up again, it was held with the venter down
or up indifferently.

The all-important lesson that Fabre draws from his
study of the Ammophiles is that they are inspired by
automatically perfect instincts, which can never have
varied to any appreciable extent from the beginning of
time. He argues that deviation from the regular rule
would mean extinction. For example, if the wasp should
sting ever so little to one side of the median line the
prey would be imperfectly paralyzed and the egg would

1 Introduction to Modern Classification of Insects, ii, 189.

AMMOPHILA AND HER CATERPILLARS

consequently be destroyed; or a sting in the wrong
place might cause the death of the caterpillar and thus
the death of the wasp larva, which, he thinks, can be
nourished only by perfectly fresh food.

The conclusions that we draw from the study of this
genus differ from these in the most striking manner.
The one preeminent, unmistakable, and ever present
fact is variability. Variability in every particular, - - in
the shape of the nest and the manner of digging it, in
the condition of the nest (whether closed or open) when
left temporarily, in the method of stinging the prey, in
the degree of malaxation, in the manner of carrying the
victim, in the way of closing the nest, and last, and
most important of all, in the condition produced in the
victims of the stinging, some of them dying and becom-
ing "veritable cadavers," to use an expressive term of
Fabre's, long before the larva is ready to begin on them,
while others live long past the time at which they would
have been attacked and destroyed if we had not inter-
fered with the natural course of events. And all this
variability we get from a study of nine wasps and fifteen
caterpillars !

In his chapter on "Methode des Ammophiles" Fabre
says that each species has its own tactics, allowing no
novitiate. "Not one could have left descendants if it

WASPS, SOCIAL AND SOLITARY

were not the handy workman of to-day. Any little slip is
impracticable when the future of the race depends upon
it." And yet we find that the prey may be stung so
slightly that it can rear and wriggle violently or so se-
verely that it dies almost at once, and in neither case is
a break made in the generations of the Ammophiles,
since in the former the egg or larva is so firmly fastened
as to keep its hold, while in the latter the dead and de-
composing caterpillar is eaten without dissatisfaction or
injury.

Nor do we, in gathering evidence for the evolution of
the instincts of these wasps, need to rely entirely upon
our own observations. Fabre himself gives many facts
which point in the same direction, but he draws a line
between those actions which are the result of mechanical
and unvarying instinct and those which come within the
sphere of reason, and in relation to which the insect must
consider, compare, and judge. Yet this line, even in the
light of his own work, is so extremely variable, needing
readjustment with every new species and often among
the individuals of the same species, that it loses for others
the meaning which it has for its author. He himself
speaks of certain individuals of the genus Sphex which
refuse to be duped when he withdraws their prey to a
distance. These, he says, are the elite, the strong-

AMMOPHILA AND HER CATERPILLARS

headed ones, which are able to recognize the malice of
the action and govern themselves accordingly, but these
revolutionists, apt at progress, he goes on to say, are few
in numbers. The others, the conservators of old usages
and customs, are the majority, the crowd. Yes, but is it
not always the strong-minded few that direct the destiny
of a race ?

Chapter III

THE GREAT GOLDEN DIGGER

THIS wasp (Sphex ichneumonea Linn.) is one of
our most beautiful species, its great size and its
brilliant color, as it flies among the flowers, serving to
make it well known to all observers of nature. During
the later part of July, all through August, and even in the
early days of September it is commonly found at work
making or storing its burrow. It is rare in our garden,
however, and we thought ourselves fortunate in being
able to keep track of one individual from the making to
the closing of the nest. Although large and powerful it
is gracefully formed. In color it is brown, varied with
bright yellow.

On the morning of the third of August, at a little after
ten o'clock, we saw one of these hunters start to dig a
nest on the side of a stony hill. After making some pro-
gress in the work she flew off and selected a second place,
where she dug so persistently that we felt confident that
this was to be her final resting-place; but when the hole

THE GREAT GOLDEN DIGGER

was two and one half inches deep, it too was deserted.
Again our wasp chose a spot and began to burrow. She
worked very rapidly, and at twenty minutes before twelve
the hole was three inches deep. At high noon she flew
away, and was gone forty minutes. The day was exces-
sively hot, about 98° Fahr., and we ourselves were only
deterred from taking a noonday rest by our fixed deter-
mination not to leave the place until we had seen all that
there was to be seen in the manoeuvres of ichneumonea.
On returning she appeared very much excited, fairly
quivering with vitality as she resumed her work. She
came up backward, carrying the earth with her mouth
and anterior legs, and went back from the opening some
little distance, when it was dropped, and she at once
went in again. While in the burrow we could hear her
humming, just as the Pelopaei do when, head downward
in the wet mud, they gather their loads for nest-building.
In five or six trips a little mass of earth would accumu-
late, and then she would lie quite flat on the heap and
kick the particles away in all directions. As the work
progressed the earth was carried further and further
away before it was placed on the ground, and as she
backed in different directions the material brought out
was well spread about from the down-hill side of the
nest. Sometimes she would spend several moments in

WASPS, SOCIAL AND SOLITARY

smoothing the debris all around, so that the opening
presented much the appearance of an immense ant-hill,
only the particles were much larger. During the first
hour that we watched her she frequently turned directly
toward us, and, sometimes remaining on the ground and
sometimes rising on her wings to a level with our faces,
appeared to be eyeing us intently for four or five seconds.
Her attitude was comical, and she seemed to be saying,
'Well, what are you hanging around here for?':

As the afternoon wore on she worked more calmly
and her fidgety and excited manner disappeared, the
excavation progressing steadily until half-past three.
At that time she came out and walked slowly about in
front of her nest and all around it. Then she rose and
circled just above it, gradually widening her flight, now
going further afield and now flying in and out among
the plants and bushes in the immediate vicinity. The
detailed survey of every little object near her nest was
remarkable ; and not until her tour of observation had
carried her five times entirely around the spot did she
appear satisfied and fly away. All her actions showed
that she was studying the locality and getting her bear-
ings before taking her departure. A fact that impressed
us very much was that with the two nests that she had
begun and then deserted she had taken no such precau-

THE GREAT GOLDEN DIGGER

tion, but simply came up and flew off. Had she made
up her mind, if we may be allowed to use the term, that
the localities were in some way unsuitable and that
hence she had no occasion to return to them ? Had she

THOROUGH LOCALITY STUDY BY SPHEX

decided, in the last instance, that she would return and
so must get her bearings ? We wondered how far the
different acts were instinctive, or were, as Huber has it,
an evidence of a "little dose of judgment." Bates, in
speaking of Monedula signata, says that he often no-
ticed it taking a few turns about the locality of its nest,
and that he was convinced that it was doing so for the
purpose of getting its bearings. Belt, having described

WASPS, SOCIAL AND SOLITARY

how he fed a specimen of Polistes carnifex with a cater-
pillar, which the wasp cut into two parts, goes on to say :
"Being at the time amidst a thick mass of fine-leaved
climbing plant, it proceeded, before flying away, to take
note of the place where it was leaving the other half. To
do this, it hovered in front of it for a few seconds, then
took small circles in front of it, then larger ones around
the whole plant. I thought it had gone, but it returned
again, and had another look at the opening in the dense
foliage down which the other half of the caterpillar lay." 1
He then remarks that when the wasp came back for the
remaining half it flew straight to its nest without taking
any further note of the locality. Both of these writers
believe that many of the actions of insects that are
ascribed to instinct are really evidence of the possession
of a certain amount of intelligence.

To return to our Sphex. When she flew away we nat-
urally supposed that she had gone in search of her prey,
and we were on the qui vive to observe every step in her
actions when she came home. Alas ! when she came back
half an hour later, she was empty-handed. She dug for
four minutes, then flew off and was gone two minutes,
then returned and worked for thirty-five minutes. An-
other two minutes' excursion, and then she settled down

1 Naturalist in Nicaragua, p. 136.
60

THE GREAT GOLDEN DIGGER

to work in good earnest and brought up load after load
of earth until the shadows grew long. We noticed that
on these later trips she flew directly away, depending
upon her first careful study of the surroundings to find
her way back. At fifteen minutes after five the patient
worker came to the surface, and made a second study,

HASTY LOCALITY STUDY BY SPHEX

this time not so detailed, of the environment. She flew
this way and that, in and out among the plants, high and
low, far and near, and at last, satisfied, rose in circles,
higher and higher, and disappeared from view. We
waited for her return with all the patience at our com-

WASPS, SOCIAL AND SOLITARY

mand, from fifteen minutes after five until fifteen min-
utes before seven. We felt sure that when she came
back she would bring her victim with her, and when we
saw her approaching we threw ourselves prone on the
ground, eagerly expecting to see the end of the drama ;
but her search had been unsuccessful, - - she carried
nothing. In the realms of wasp-life, disappointments
are not uncommon, and this time she had us to share
her chagrin, for we felt as tired and discouraged as she
perhaps did herself. When we saw her entering without
any provision for her future offspring, we were at a loss
what to do next ; and it may be that this state of mind
was shared by her also, for she at once began to fill in the
entrance to her nest. We now thought it time to act,
and decided to capture her, to keep her over night in
one of our wasp-cages, and to try to induce her to re-
turn to her duty on the following day. We therefore
secured her in a large bottle, carried her to the cottage,
and having made every possible arrangement for her
comfort, left her for the night.

On the next morning, at half after eight o'clock, we
took Lady Sphex down to her home, and placed the
mouth of the bottle so that when she came out she had
to enter the nest. This she did, remaining below, how-
ever, only a moment. When she came up to the surface

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SPHEX DRAGGING GRASSHOPPER TO HER NEST

THE GREAT GOLDEN DIGGER

she stood still and looked about for a few seconds, and
then flew away. It surprised us that having been ab-
sent from the place for so many hours, she made no
study of the locality as she had done before. We thought
it a very unpromising sign, and had great fears that she
was deserting the place and that we should see her no
more. One would need to watch a wasp through the
long hours of a broiling hot day to appreciate the joy
that we felt when at nine o'clock we saw her coming
back. She had no difficulty in finding her nest, nor did
she feel any hesitation as to what ought to be done next,
but fell to work at once at carrying out more dirt. The
weather, although still hot, had become cloudy and so
threatening that we expected a down-pour of rain every
moment, but this seemed to make no difference to her.
Load after load was brought up, until, at the end of an
hour, everything seemed completed to her satisfaction.
She came to the entrance and flew about, now this way,
and now that, repeating the locality study in the most
thorough manner, and then went away. At the expira-
tion of an hour we saw her approaching with a large
light green meadow-grasshopper, which was held in the
mouth and supported by the fore legs, which were folded
under. On arriving, the prey was placed, head first, near
the entrance, while the wasp went in, probably to reas-

WASPS, SOCIAL AND SOLITARY

sure herself that all was right. Soon she appeared at the
door of the nest and remained motionless for some mo-
ments, gazing intently at her treasure. Then seizing it
(we thought by an antenna) she dragged it head first
into the tunnel.

The laying of the egg did not detain her long. She
was up in a moment and began at once to throw earth
into the nest. After a little she went in herself, and we
could plainly hear her humming as she pushed the loose
material down with her head. When she resumed the
work outside we interrupted her to catch a little fly that
we had already driven off several times just as it was
about to enter the nest. The Sphex was disturbed and
flew away, and this gave us an opportunity to open the
burrow. The grasshopper was placed on its back, with
its head next to the blind end of the pocket and the legs
protruding up into the tunnel.

We found that the egg of the wasp, which was seven
millimeters long, and rather slender, was placed on the
under face of the thorax at a right angle to its length,
and parallel with the femur of the second leg. This leg
had apparently been stung so that it had swollen and
folded over the free end of the egg, which was thus firmly
held in place at both extremities. 1 Upon examination

1 Fabre says that all of the three species of Sphex that he has

THE GREAT GOLDEN DIGGER

we found that the abdomen of the grasshopper was beat-
ing regularly and automatically, but the closest obser-
vation failed to discover any other movements, nor
would any part respond when stimulated. At three
o'clock in the afternoon we found the abdomen still
pulsating, and, in addition, that both antennae moved
several times when we lifted off the cover of the jar that
contained the insect. "On the next morning the grass-
hopper was very lively, the antennae and labial palpi
moving without stimulation. It had passed faeces, and
was able to lift its abdomen, which was curved over to-
ward the head, as it lay on its back, frequently and with
considerable violence. On the next afternoon there was
no change in the movements, but the egg was dead. On
the seventh the grasshopper responded to stimulation
by a slight movement of the palpi and the end of the
abdomen. The pulsation of the abdomen continued
until the afternoon of the eighth, when it ceased, no effort
of ours succeeding in starting it again. The movements
of the antennae and palpi grew weaker and weaker on
the ninth, and on the morning of the tenth the insect

studied lay the egg on this identical place. He places immense impor-
tance on this point, which seems to us rather fanciful. He also no-
ticed the pulsation of the abdomen and the movements of the other
parts.

WASPS, SOCIAL AND SOLITARY

was dead, a period of five and a half days having elapsed
since it was brought into the nest.

We had not supposed that the digging up of her nest
would much disturb our Sphex, since her connection
with it was so nearly at an end ; but in this we were mis-
taken. When we returned to the garden about half an
hour after we had done the deed, we heard her loud and
anxious humming from a distance. She was searching
far and near for her treasure house, returning every few
minutes to the right spot, although the upturned earth
had entirely changed its appearance. She seemed unable
to believe her eyes, and her persistent refusal to accept
the fact that her nest had been destroyed was pathetic.
She lingered about the garden all through the day, and
made so many visits to us, getting under our umbrellas
and thrusting her tremendous personality into our very
faces, that we wondered if she were trying to question us
as to the whereabouts of her property. Later we learned
that we had wronged her more deeply than we knew.
Had we not interfered she \vould have excavated several
cells to the side of the main tunnel, storing a grasshopper
in each. Who knows but perhaps our Golden Digger,
standing among the ruins of her home, or peering under
our umbrella, said to herself: " Men are poor things;
I don't know why the world thinks so much of them."

THE GREAT GOLDEN DIGGER

Dr. Packard describes Sphex ichneumonea as nesting
in gravelly walks, where it digs to a depth of from four
to six inches, using its jaws and fore legs to do the ex-
cavating. While the wasps that he observed completed
the hole in half an hour, ours was actually at work a little
over four hours. Her nest,
as is shown in the drawing,
measured seven and one half
inches to the beginning of
the pocket, which was three
quarters of an inch wide by
one and one half inches long.
The yellow-winged Sphex, a
native of France, was found
by Fabre to take several
hours to make her nest, work-
ing in hard ground ; while
another species, also studied
by this observer, dug in soft
earth, either in the ground or in the accumulations on
the roofs of buildings, and completed her work in fifteen
minutes at the most. These variations in the habits of
closely related species should be carefully studied in
any attempt toward an explanation of their instincts.

Fabre's account of the genus Sphex, as it appears in

NEST OF SPHEX

WASPS, SOCIAL AND SOLITARY

France, is most interesting. He says that the yellow-
winged species, living in colonies, first digs her nest
and then secures her cricket, which is brought, on the
wing, to the neighborhood of the burrow, the last part
of the journey being accomplished on foot. The cricket
is dragged by one of the antennae, and is not left until
the nest is reached. It is then placed so that the antennae
reach precisely to the opening, and there it is left while
the wasp descends hurriedly into the depths of the bur-
row. In a few seconds she reappears, showing her head
outside, seizes the antennas of the cricket, and drags it
below. These manoeuvres are repeated with a striking
degree of invariability.

The other Sphex first secures her prey, which is too
large and heavy to be carried far, and then digs her
nest in the neighborhood of the capture. This being
done, she returns to her victim, and straddling it drags
it by one or both of the antennae. Sometimes the whole
journey is accomplished at once, but oftener the wasp
suddenly drops her burden and runs rapidly to her
nest. Perhaps it seems to her that the entrance is
not large enough to accommodate a creature of such
size; perhaps she imagines some imperfections of detail
which would impede the process of storing it up. The
work is retouched, the doorway enlarged, the threshold

THE GREAT GOLDEN DIGGER

smoothed. Then she returns to her booty and again
starts with it. After a few steps the Sphex seems to be
seized with another idea. She has visited the doorway,
but has not seen the interior. Who knows whether all
is well within? She drops her prey and again runs off.
The visit to the interior is made, more touches are given,
and once more she returns. Will the journey be accom-
plished this time? Impossible to say. Some wasps,
more given to worry than others or more forgetful of
the small details of architecture, to repair their neglect
or to clear up their suspicions, abandon their booty five
or six times in succession to retouch the nest or simply
to visit the interior. The prey, once brought to the
nest, is carried in without the preliminaries that are
common to the other species.

Chapter IV

SEVERAL LITTLE WASPS

IN a search for the nest of one of our garden wasps
we found, in the woods beyond the fence, an old,
weather-beaten stump which was riddled with holes
both large and small. The large ones were evidently
the passage-ways of ants, and were in constant use. The
small ones seemed to be uninhabited ; but thinking they
might contain the nests we were in search of, and hop-
ing that if we watched long enough we might see our
wasps flitting in and out, we settled ourselves close by.
We were resolved to stay as long as was necessary, and
we blessed the fate that made it our duty to sit on the
grass under the shade of a wide-spreading oak rather
than in the distressing glare and heat of the garden ; for
this was on the tenth of July, and the weather was what
the farmers call "seasonable."

Twenty, thirty, forty minutes passed. Our eyes ached
with persistent gazing, and we had nearly made up our
minds that the likely-looking little holes were unten-
anted, when lo! a tiny wasp, carrying something which

SEVERAL LITTLE WASPS

we could not see distinctly, darted into one of them. It
was gone so quickly that we could not be sure that it
was the species we were looking for, and when it re-
appeared, after two or three minutes, we saw that it was
not. This point being determined, we watched the hole
with redoubled interest.

It was wearisome work, for the wasp stayed away a
long time, and we dared not let our gaze wander lest she
should slip in without our knowledge. At the end of
thirty-five minutes she returned, but again we failed
to see what she carried. She flew with great rapidity,
and we scarcely caught sight of her before she vanished
into her nest. We could not but wonder at the ease and
certainty with which she recognized her own doorway
among the hundreds of holes on the side of the stump.
This power of localization, while it is one of the most
common among wasps, is surely also one of the most
remarkable.

Our little Rhopalum pedicellatum, for that proved to
be her name, made six more journeys within the next
two hours. At the end of this time we opened the tunnel,
and, after a great deal of sawing and cutting, succeeded
in finding the nest five inches from the surface. It was
nothing but a slight enlargement of the gallery, in the
soft decaying wood. In it we found thirty-three gray

WASPS, SOLITARY AND SOCIAL

gnats, all of them, except two, being dead. On one of
the dead ones was the egg, which had probably been
laid within a few hours.

The egg hatched two days later, on July twelfth, but
on the fifteenth the larva died. By this time many of the
gnats looked very dry, although we had tried to arrange
for both moisture and ventilation by packing the bottom
of the tube with pith and covering the top with muslin.

Further watching gave us one more wasp of this
species, in the same stump. This time the nest was only
two inches from the surface. It contained four dead
gnats and two live ones, but no egg, showing that the egg
is not always laid on the first ones stored.

Much later in the season, toward the end of August,
we found another species of Rhopalum which proved to
be new, and for which Mr. Ashmead has proposed the
name rubrocinctum, since it wears a red girdle around
the front end of the abdomen, being otherwise dressed in
black like pedicillatum. It makes its home in the stalks
of raspberry bushes. We opened a stem which contained
thirteen compartments, separated by partitions of pith.
These were filled with black, gray, and green gnats,
which were packed in so closely that they were doubled
over and pressed out of shape. Each cell contained
from twentv-five to thirtv gnats. In some of them were

J * O

SEVERAL LITTLE WASPS

cocoons, in others larvae, and in one was an egg. The
gnats were very carefully examined, and all of them,
from the cells that had been filled last as well as from
those provisioned earlier, were dead.

Other species of Rhopalum are said to prey upon
spiders and aphides.

In studying the species that come in our way we are
continually developing distinct likings for some kinds
above others. The ap-
pearance of one of
these favorites is al-
ways hailed with de-
light, and when the
season's work is over
we remember them
with lively pleasure.

OXYBELUS QUADRINOTATUS

It is thus, dear little

Oxybelus, that we dwell upon the thought of you and
your pretty ways. No other wasp rose so early in the
morning, no other was so quick and tidy about her
work, so apt and business-like without any fuss or
flurry. No other was more rapid and vigorous in pur-
suit of her prey, and we think with admiration and
gratitude of the number of flies that you must have
destroyed in the course of the summer.

WASPS, SOLITARY AND SOCIAL

O. quadrinotatus is only one-quarter of an inch long,
and is dark gray with four whitish spots on the abdomen.
It was before nine o'clock in the morning that, while out
on an early inspection tour in the garden, we saw one of
these wasps descend upon a sandy spot, and after a mo-
ment's rapid scratching with her first legs enter the hole
that she had opened. Under her body she was carrying a
fly which looked like the common domestic species. It
was upside down, its head being tightly clasped with the
third pair of legs, and all of its abdomen projected be-
yond the abdomen of the wasp. Ashmead quotes from
Fabre the remarkable statement that Oxybelus carries
her flies home impaled on her sting, an idea that prob-
ably arose from the fact that nearly the whole body of
the fly is visible.

Our new-found wasp stayed only a moment in her
nest, although, as we afterward found, it was long
enough for her to lay her egg on the fly. When she came
out she quickly smoothed the sand over the spot with
her head and legs so that there was nothing to mark the
nest, and flew away. In three minutes she returned with
another fly. She alighted two or three inches away, and
scratched for an instant, but quickly saw her mistake,
and found the right spot.

Again and again the pretty little worker went and

SEVERAL LITTLE WASPS

came, while we sat watching close by, admiring her deft
handiwork in opening and closing the nest and wonder-
ing at the ease with which she found it at each return.
There was nothing tiresome or dilatory about this
species, and within twenty minutes we had seen six flies
stored up. The nest was closed and the place smoothed
over every time before she went away, but when she
entered she left the door open behind her. We once tried
to make her drop the fly, but when disturbed she flew up
and alighted on a plant near by, keeping her hold on
it. The whole performance was brisk and business-
like, but without the feverish hurry of Ammophila and
Pompilus.

After the sixth fly was taken in we were afraid to let
her go again, thinking that the nest must now be com-
pletely provisioned, and that she would not return. She
was such a charming little wasp, scarcely bigger than a
fly herself and yet so useful in her industry, that we
hated to disturb her ; but as we were obliged to have her
for identification we first caught her, and then opened
the nest. It contained only the flies that we had seen
taken in, the egg being attached to the one lowest down,
on the left side, between the head and the thorax. It was
long and cylindrical. The flies were dead, but showed
no marks of violence. We learned later that it takes

WASPS, SOLITARY AND SOCIAL

Oxybelus two hours to make her nest so that this one
must have been prepared the day before.

The egg, which was laid just before nine o'clock on the
morning of August seventh, hatched at a little after nine
on the morning of August eighth. The larva began to
eat at once, and devoured all the inside of the thorax
and abdomen of the fly to which it was attached, in the
first twenty-four hours. On August twelfth it had
reached the sixth fly, and we supplied it with three more.
On August fourteenth these were gone, and we again
replenished its larder, this time with two flies. The larva
had partly eaten these when something went wrong. Its
appetite failed, and on August sixteenth it died.

On further acquaintance this wasp lost none of her
charm, - - indeed, she gained in interest from the almost
human curiosity that she showed about the affairs of
other people. Where several were living close together
one of them would sometimes stop digging her own nest
to perch on a weed and watch the labor of another, and
we once saw an especially inquisitive character burrow
through the closed door and enter the home of her next-
door neighbor.

We find but meagre notes on the genus Oxybelus.
Ashmead says that no observations have been made on
the American species, but that in Europe they are found

78 .

SEVERAL LITTLE WASPS

to burrow in sand and to provision their nests with dip-
terous insects. He says also that according to Verhoeff
the species in this genus do not paralyze their prey by
stinging, as they are unable to do so on account of the

NEST OF OXYBELUS

rigidity of the abdomen, but that instead they crush the
thorax with the mandibles just beneath the wings, the
centre of the nervous ganglia. He found in one nest a
dozen flies, and all had the thorax crushed and were
dead. In the case of our wasp we do not know how the
flies were killed, but there was no crushing of the tho-
rax. The larva devoured, in all, ten flies. At the time of
its death it had probably finished the larval stage of its

WASPS, SOCIAL AND SOLITARY

existence, since nine days had elapsed since the hatching
of the egg. It may be that this period just before pupa-
tion is a critical point in the life history of a wasp, for we
lost several of our nurslings at this time, and Fabre has
noted that when, on account of the presence of parasites,
the larva of Bembex rostrata had lacked something of
its usual amount of nourishment, it perished miserably
at the end of its larval stage, not having strength enough
to spin its cocoon. No waspling in our charge ever
died from lack of nourishment — on that score our
consciences are clear ; but it was difficult to make their
conditions quite normal, and for this reason we may
have been, indirectly, the cause of their death.

The way in which our Oxybelus carries its prey is pe-
culiar to itself. Bembex and Philanthus also hold their
prey under the body, but use the second pair of legs, so
that it does not project behind except at the moment of
entrance into the nest. Quadrinotatus, as we could dis-
tinctly see, since she passed close to us several times in
quick succession, clasps the head of her victim in the
third pair of legs, and flying thus, with its whole body
sticking out behind her, she certainly presents a very
remarkable appearance.

Aporus fasciatus is a dark gray species, and is less than
half an inch in length. We were working one hot day in

SEVERAL LITTLE WASPS

the melon field, when we saw one of these little wasps
going backward and dragging a female of Maevia vittata
which was much larger than she was herself. She twice
left it on the ground while she circled about for a mo-
ment, but soon carried it up on to one of the large melon
leaves, and left it there
while she made a long and
careful study of the local-
ity, skimming close to the
ground in and out among
the vines ; at length she
went under a leaf that lay
close to the ground and
began to dig. After her
head was well down in the
ground we broke off the

.. . . , APORUS FASCIATUS

leaf that we might see her

method of work. She went on for ten minutes without
noticing the change, and then, without any circling,
flew off to visit her spider. When she tried to return
to her hole it was evident that some landmark was
missing. Again and again she zigzagged from the
spider to the nesting-place, going by a regular path
among the vines from leaf to leaf and from blossom
to blossom, but when she reached the spot she did not

WASPS, SOCIAL AND SOLITARY

recognize it. At last we laid the leaf back in its place
over the opening, when she at once went in and resumed
her work, keeping at it steadily for ten minutes longer.
At this point she suddenly reversed her operations and
began to fill the hole that she had made, kicking in the

earth until the entrance was hidden. She then glanced
at the spider, selected a new place, and began to dig
again. Surprisingly large pellets of earth were carried
out, backward, and loose dirt was kicked under the
body by the first legs. At the end of two or three min-
utes she paused and remained perfectly still for a time,
considering the situation. Her conclusion was adverse
to the locality, for she soon filled in the hole, looked once
more at the spider, and started a third nest in a new
place. This in turn was soon abandoned, as was also a
fourth. The fifth beginning was made under a leaf that
lay close to the ground, so that we could not see her at
all. Fasciatus ! had we had the naming of her she
should have gone down the ages as exasperans ! We had
now watched her for an hour in the intense heat ; the
bell for the noonday meal had sounded, hunger and
thirst had descended upon us, and most devoutly did
we hope that she was suited at last, but no - - after
twenty minutes' work this place also was abandoned,
and a sixth nest started. This, however, was the final

SEVERAL LITTLE WASPS

choice, and after forty-five minutes spent in digging, it
was completed. As the spider was brought toward the
nest it was left again and again while the nervous little
wasp flew to the hole, went in, examined, and came out
again. At last she backed in, caught the spider by the
abdomen, and dragged it down. It was too big - - the
head stuck in the hole; but she pulled from below while
we pushed gently from above, and it slowly disappeared.
When she came out we opened the nest and took the
spider. The egg was fastened to the middle of the left
side of the abdomen. This one, as was also the case with
a second and third afterward taken from fasciatus, was
much less affected by the poison than is usual among the
victims of solitary wasps, moving from the time it was
taken, without any stimulation, and improving rapidly
from day to day. Our second spider appeared to be
blind, and died upon the sixteenth day, while the third
had entirely recovered by the seventeenth day after it
was stung, and was released. Fasciatus, then, probably
depends upon packing her victim in tightly to keep it
quiet.

It was three days and a half before the egg that we
had taken hatched. The larva developed rapidly, retain-
ing its hold at the spot to which the mother had fastened
it. The spider remained alive for six days, and the larva

WASPS, SOCIAL AND SOLITARY

continued to grow for two days longer, when it died
also, being at the time about two thirds grown. We had
great trouble in protecting our growing larvae from the
inroads of fungi, and this was one of the many that per-
ished from that cause.

The next example of fasciatus that came under our
notice was a remarkable contrast to the one that we
have just described, being as slow and dignified as the
other was nervous and hurried. She chose a place and
kept to it, her steady labor being interrupted only by
occasional visits to the spider; but it took her fifty min-
utes to complete the nest. When finished it was a small
gallery running down obliquely for an inch and a half
into the ground.

The only habit that this species can claim as peculiar
to itself is the strange and useless one of filling up the
partly made nests that it is about to abandon. We have
never seen the sense of order carried to so high a point
in any other wasp.

On a hillside near our cottage stands a log cabin,
deserted and untenanted save for small creatures of the
wild, which, though a favorite spot with wood-boring
wasps, is an unprofitable place for study because of the
difficulty of cutting out their nests without destroying
property. One day in early July, however, when we

WASP HOMES IN THE LOG CABIN

SEVERAL LITTLE WASPS

were in the full fervor of hunting and longed to utilize
every moment, the wasps in our garden seemed to have
resolved that enjoyment and enjoyment only was their
destined end and way, and became so exasperatingly
idle that in disgust we turned to the cabin. For half an
hour we saw nothing more exciting than a Trypoxylon
immuring her victims and a Pompilus hunting spiders
under the eaves, but at the end of that time Passolocus
annulatus, a tiny wasp new to us, came flying quietly
along and entered one of the holes with which the ends of
the logs were riddled. She was carrying an aphis in her
mandibles, and when this was duly stored she reap-
peared and flew away. She had probably just renewed
her work after a spell of rest, since from this time on for
nearly an hour she came back regularly every four or five
minutes. She nearly always alighted on a blade of grass
before going into the nest, but did not appear to be
malaxing her prey. Presently another stage in the game
was reached. She no longer brought aphides, but little
pellets of mud with which she plastered up the opening.
After she had finished this task and departed, we care-
fully chiseled into the log and laid bare the nest. The
tunnel ran in for about three inches, and ended in three
pockets which were well stocked with dead aphides,
there being fifty-seven in all. The innermost cell con-

WASPS, SOCIAL AND SOLITARY

tained a larva, and in the others were eggs, one of which
hatched on the next day and one on the day following.
This second one was probably laid just before the nest
was sealed, giving forty hours for the egg stage; and it
proved to be the healthiest of the three. The others per-
ished in early infancy; but this one passed twelve days
in eating, not only its own share of provisions, but those
destined for the other members of the family as well,
and then spun its cocoon.

We afterwards saw many of these wasps working in
the logs of the cabin, and noticed that they seemed to
have seasons of leisure alternating with spells of active
work, as though when one cell had been filled up and
the egg laid they felt at liberty to amuse themselves for
a time before beginning on another. When an entirely
new residence was to be chosen they went house-hunting
among the old holes in the logs ; and whether they had a
high standard of sanitary conditions, or whether they
objected to making extensive repairs, a great many
places were examined and rejected before they settled
down. The choice once made, many loads of pith were
carried out before the little householder was satisfied.
After the new abode was put to rights, the wasp would
pass a whole day in rest, spending much of the time in
looking out of her doorway and perhaps in observing

SEVERAL LITTLE WASPS

the doings of her neighbors, but when she began to work
she was very industrious, and allowed nothing to inter-
fere with her labors, paying no more attention to us, no
matter how closely our curiosity led us to interrogate
her, than if we had been trees blown about by the
wind.

Some of the wasps dig deep into the stems of bushes
to form galleries for their nests, but we found one wise
genus that went in only far enough to make one or two
cells, thus saving the trouble of carrying her cuttings
thirty or forty centimeters in direct opposition to the
force of gravity. This was Odynerus, whose nests we
found in July, in blackberry and raspberry
stems. Our first species was perennis, whose
nests bear her mark in the shape of a pellet
of earth placed above each mud partition.
One of her cells contained a wasp larva and
about sixteen caterpillars, nearly one third
of which were dead, while the rest were more
or less lively. They seemed to have been
stung near the anterior part, as the last three
or four segments were jerked up violently
when touched. The larva went on eating,
and the caterpillars went on dying from hour to hour.
At the end of the eighth day, the baby wasp finished

NEST OF
PERENNIS

WASPS, SOCIAL AND SOLITARY

its meal, having eaten all that had been provided for
it, as well as two dead caterpillars from another
nest.

Much interest attaches to the way in which Odynerus
lays her egg, since instead of following the common
fashion of fastening it to the prey she suspends it by a
tiny filament of web from the wall or ceiling of her cell.
Thus in O. reniformis, nesting in the ground, it is hung
from the ceiling, a mass of very imperfectly paralyzed
caterpillars being collected below, and when the larva
comes out the thread lengthens until the tiny jaws reach
the food supply. Startle it ever so slightly and the wasp-
ling retreats by way of its web, descending again only
when everything is quiet. For twenty-four hours it
retains this path to safety, and then, growing bold, it
drops down and feeds at its ease.

We had opened hundreds of plant stems in quest of
these suspended eggs without being so fortunate as to
find one, and were therefore much pleased when our
kind friend, Dr. Sigmund Graenicher, whose interest
in bees keeps him in touch with out-of-door happenings,
and who has given us much valuable help, brought us
two stalks, one of which had in it a nest of O. conformis,
while the other contained two freshly provisioned cells
of O. anormis. In all three the egg had been hung from

SEVERAL LITTLE WASPS

the side of the cell about one third of the way down, and
in the nest of conformis, from which all but one of the
caterpillars had fallen, it hung loose against the wall.
In the other nests the lower part was packed
tightly with sixteen small larvae, upon which
lay the egg, supported in a horizontal posi-
tion, although attached to the side wall ex-
actly as in conformis, and above were eight
more caterpillars, the whole forming a com-
pact mass shut in by the usual paitition of
mud. So closely were they crammed in that
after counting them we were unable to get
them all back again, and although motion-
less in their narrow quarters they became
quite active when relieved from pressure.
This is an entirely different arrangement from that of
O. reniformis, and since the larva is in contact with the
caterpillars from the moment of hatching the manner
of the egg-laying has no significance in relation to the
safety of the young.

Conformis hatched on the morning after we received
it, sloughing off the skin of the egg, but remaining at-
tached to it, and thus doubling the length of the thread
by which it hung. The caterpillar was slightly separated
from it, and it seemed to have no notion of feeling about

NEST OF
ANORMIS

WASPS, SOCIAL AND SOLITARY

for its food, eating nothing for twenty-four hours, but
growing and developing nevertheless. We now piled
up some caterpillars in contact with it, and it began to
eat, but after its own caterpillar and as many as we dared
take from anormis were gone it stubbornly refused to
take soft, tender little spiders, or caterpillars out of our
garden; and it perished, a victim to prejudice.

The two eggs of anormis were probably laid within a
few hours of each other, since they had both hatched
on the morning of the third day, and had broken from
their attachment, beginning to eat at once. They co-
cooned on the fifth day after hatching.

We had long wished to find a nest of O. capra, and
early in September fortune favored us. A neighbor of
ours keeps a large tin horn hanging under the porch.
One day when she wished to use it, no amount of blow-
ing would bring forth a sound ; and when she unscrewed
the mouthpiece to investigate the matter, out tumbled
several small green caterpillars and a quantity of dry
mud. When we heard of this incident we begged that if
it should be repeated the nest and its contents might be
saved for us; and on the second of September we re-
ceived the mouthpiece of the horn with a message to
the effect that a wasp had been working at it for some
days. Examination showed that there were three cells,

SEVERAL LITTLE WASPS

each containing a larva and a supply of caterpillars, of
which there were ten in the cell most lately formed, and
only one left uneaten in the oldest. The caterpillars, all
of them being alive, together with the wasp larvae, were
transferred to a place in which they could be conven-
iently watched. None of the caterpillars died until they
were attacked. The larvae ate all the food that was pro-
vided, the oldest one cocooning on the fourth, and the
second one on the seventh of September. Of the third,
we have no record, excepting that the caterpillars had
all been eaten on September eighth.

We happened to be passing through our neighbor's
grounds at nine o'clock on the morning of September
fifth, and calling to ask whether there had been any
more visits from the wasp, we learned that capra had
been seen making a mud partition in the horn on the
day before. While we were speaking she arrived and
entered the mouthpiece, where she remained for about
ten minutes. When she departed we found that she had
laid her egg, which we carried away with us, wishing
to determine the length of the egg stage. This proved
to be longer than that of any wasp that we had hereto-
fore known, for not until the morning of September
ninth did the larva make its appearance, the egg skin
bursting and leaving its tenant free to crawl away. In

WASPS, SOCIAL AND SOLITARY

other genera the egg changes into a larva imperceptibly,
there being no sloughing off of the skin.

Capra, then, first finds a suitable crevice, and builds a
partition across the inner end, the earth being scratched
up from some dry, bare spot, and moistened in her
mouth. Before gathering the ten or twelve small cater-
pillars that are to provision the cell, she lays her egg;
and although we could not be sure, we thought that in
this case as in the others it was suspended.

Unless the cell is tightly packed at the beginning,
capra certainly needs the filament, for her caterpillars
were so far from being reduced to a state of decent im-
mobility that we had to press wads of cotton into the
tubes in which they were kept to prevent them from
wriggling out of the way of the larva. None of our
larvae, not even the one-day-old ones, were injured by
their activity ; but had the egg been left to its fate among
them it might have perished.

Later in September we found O. vagus bringing pel-
lets from a sharp-edged hole in the ground. Her method
was to carry each load on the wing to a distance of ten
or twelve inches, where it was dropped without the lively
fling with which Ammophila discards her lump of dirt.
The red end of a match stuck into the ground two
inches away proved very disquieting to the dainty little

SEVERAL LITTLE WASPS

wasp. These colored matches were a great convenience
in marking nests, and as we were using them constantly,
we did not guess, for a time, what the trouble was. For
half an hour she went and came, circling about, alight-
ing upon plants, and seeming entirely absorbed in
examining them with the minutest care, even alighting
upon our hands with most engaging friendliness, but
pretending all the time that the nest was naught to her.
When the offending object was removed she hurried
in at once and resumed her work. The storing was not
begun until the next morning, when she took in six
caterpillars of very different sizes, at intervals of from
ten to twenty minutes, and then filled the hole. We
hoped to find the little chamber arranged as in reni-
formis, but had not skill enough to excavate in such a
way as to show the internal plan. It is remarkable that
this genus, with only one set of tools for all its species,
has worked out such different styles of architecture, the
ground nests bearing no resemblance to those cut out
of woody stalks ; and its flexibility is shown in the use
of empty snail shells by a foreign species, as well as
by capra's habit of partitioning off convenient crevices
found ready made.

The prettiest nests that we have seen in stems are
those of Plenoculus peckhamii, which separates its

WASPS, SOCIAL AND SOLITARY

cells, not by solid partitions, but by numerous granules
of earth, which are used by the larvae for forming the
case of the cocoon. One raspberry stalk that we opened
had at the bottom six of these mud cocoons, and above
these three larvae eating, each in its own compartment,
the provision in this case consisting of immature bugs
of the genus Pamera. Sometimes the stalk which is
being filled by Plenoculus attracts the fancy of a bee or
of another wasp, as is shown by the upper cells being
filled by Osmia or Crabro, or sometimes Plenoculus
builds above the bee cells. When a number of wasp
eggs are placed in a plant stem, the last one laid is the
first to hatch. The different habits of the Hymenoptera
in this respect are very interesting. In the case of Cera-
tina dupla, the small carpenter bee, the egg first laid
hatches first, those above following in regular order.
The lower ones wait patiently in their cells until the one
in the top cell has matured, and then they all come out
at once. When two species occupy the same stalk, the
lack of adjustment probably results in the destruction
of those lower down, excepting in the case of the cuckoo
flies, which have acquired the habit of gnawing their
way out at the side of the stem.

Chapter V

CRABRO

THE highest point of the island is crowned by a
great group of linden trees ; and one day their
perfume, carried by the wind far over field and wood,
was calling everything that had wings to gather the rich-
est of all the gifts that July can offer. We, too, were
drawn to the spot, and found the great blossoming domes
thrilling and vibrating with life. For miles around, the
bees, wasps, and butterflies had gathered to the feast;
and we seemed to touch the high-tide of the year in the
scent of the flowers, the humming throng of happy
creatures, and the vision of it all against the summer
sky.

Below, in a great root that had pushed above ground,
five little wasps, by name sexmaculatus, of the worthy
but unimaginative genus Crabro, resisting the intoxica-
tion of the linden flowers, were sawing and cutting in
the most humdrum and practical manner. One of
them, presumably the earliest riser, was well down in
the root, and came backing up once in a while, pushing

WASPS, SOCIAL AND SOLITARY

a lot of wood dust out of the hole. This was spread out
by means of legs and mandibles, and was then blown
away by the fanning wings of the little worker, who cir-
cled about just above the ground until the last grain had
disappeared. Here was another way of protecting the
home. The fresh dust might attract the attention of
some cuckoo-like insect who would lay her egg within ;
and therefore it was dispersed, just as Ammophila car-
ried out her pellet and flung it to a distance, and Sphex
spread evenly over the ground the mass of earth that
she carried from her hole.

After this series of actions had been repeated several
times the wasp flew away to hunt. We afterward found
that she had finished the third in a set of cells leading
from a main gallery. On her return we delayed her to
see what she was carrying. She showed no fear, but
alighted close by, and while she was trying to transfer
to the third pair of legs the fly that she was clasping with
the second pair, it escaped and flew gayly away. Flies
are plenty, however, and she soon had another which
she was permitted to store ; and from that time she
worked busily until we left her at noon. It took her
from two to ten minutes to catch her fly, and at each
return two or three minutes were spent in the nest. On
opening her tunnel some days later, we found within

SEXMACULATUS IN THE LINDEN ROOTS

CRABRO

not only flies, but long-bodied gnats, and all of them
seemed to have been brought home uninjured. When
the freshest cell was opened some flew away, others
were walking about, and all were lively. The wasp egg
was laid on the under side of the neck ; and although
we could not be certain of the exact time of laying we
thought it hatched at the end of thirty-six hours. From
ten to sixteen flies were provided for each larva.

A month later we found Crabro lentus nesting in the
ground. Her tunnel ran down obliquely for six and one
half centimeters, and had an enlargement at the end.
Two bugs and a fly were in the nest, when we opened it
before the provision was completed. To find sexmacu-
latus taking both flies and gnats was surprising, so rigid
are the family traditions of the wasps; still, she might
feel that so long as she drew the line at Diptera she was
all right. But to believe that one wasp, a Crabro, too,
with all the marks of conservatism about her, would
take such diverse things as bugs and flies, is almost too
much to believe. It is true that Crabro wesmaeli is said
to use both flies and bugs;1 but some accident may
have led to this supposition, and stronger evidence is
needed to prove that there is variability in so deep
seated an instinct.

i Sharp, Insects, page 130.
101

i \

WASPS, SOCIAL AND SOLITARY

The Crabro wasps all have pleasant ideas as to where
they want to live, but interruptus excels in the choice
of a dwelling place. We lately found ten or twelve of
them in Milwaukee, nesting in an old log on the shore
of Lake Michigan, and when they opened their doors
in the morning they had before them the splendor of the
great bay ; but calm in the midst of the glory they never
paused on the threshold, as Cerceris would have done,
to take a look at the world before going to work. One
morning the earliest riser in our little colony was begin-
ning the day at half past nine. Of good size for a Crabro,
with a square determined-looking head and very direct
and business-like manners, she proceeded to cut out
a new chamber for provisioning. These chambers are
nothing more than enlargements of the long gallery,
such as are made in stems by related species. At ten
o'clock she departed on a hunting excursion among the
bushes on the bank above us, and came back in eight
minutes, carrying, much to our surprise, a white- winged
moth, which was clasped under the body by the second
and third pairs of legs, and was passed back to the third
pair as she alighted before entering. A moth is an inno-
vation, a delicacy new to the accepted idea of what a
Crabro larder, accustomed to Diptera, should contain.
A moment later she was off again, but this time did not

102

CRABRO AND HER WHITE MOTHS

CRABRO

succeed so quickly, coming back twice empty-handed
for brief visits, and bringing in a load at the end of half
an hour. It took six moths to provision the cell, and as
the number neared completion her interest and energy
seemed to wax greater, the hunting intervals shortening
to five, and even to two minutes. We found afterwards
that some of the moths were alive and some dead, and
that she packed them lengthwise, one after another,
into the closely fitting chamber. At a little before eleven
o'clock the cell was filled, and the wasp retired from
sight, closing the door behind her. We thought that she
was resting, but presently the protrusion of wood dust
showed that she was enlarging her house, and an hour
later she came out and began to hunt again. By this
time half a dozen were working. Before leaving for the
first time in the morning each one made a thorough
study of the place, and on returning they entered their
own doors, which were standing open, without hesita-
tion, the long white wings of the moths trailing behind
them. Four species were represented in the nests that
we opened.

Many species of Crabro make their nests in the stems
of plants, and among these is stirpicola, which is seen
in numbers, through the middle of July, flying about in
a leisurely way, though it is only toward the end of the

105

WASPS, SOCIAL AND SOLITARY

month, or in the early days of August, that they settle
down to the work of making their homes. On the after-
noon of July twenty-seventh, after some very lively
work in the heat of the day, we walked down to the

berry garden at half past five
o'clock, rather to rest our-
selves than with the thought
of undertaking anything new;
but a wasp - hunter cannot
afford to choose his own
hours, and we thankfully

CRABRO STIRP1COLA

accepted the sending of for-
tune when we came upon a stirpicola busy at work in
digging out her nest. She had only begun to excavate,
and had reached a length just equal to that of her own
body. Her manners were an agreeable contrast to those
of the wasps that we had been watching through the
day. The feverish excitement of their ways seemed
quite in keeping with the burning heat of noon, while
Crabro's slow and gentle movements harmonized per-
fectly with the long shadows of evening. To fully appre-
ciate the difference between Pompilus or Ammophila
and Crabro it is necessary to see them at work. The
one is the embodiment of all that is restless, vying
with the humming-birds in swiftness and energy, while

1 06

CRABRO

the other is calm, quiet, and stately in all that she
does.

Some ten feet away was a second stirpicola, and this
one, to judge from the depth to which she
had penetrated, must have been at work for
about two hours. We watched them both,
and saw them bring up load after load of
pith. They bit out the pellets with their
mandibles, and passed them back between
the legs and under the body until a quantity
had accumulated above the tip of the abdo-
men. They then walked backward up the
stem, and thus pushed out the mass as they
came to the top. Often they used the hind
legs to assist in getting it out of the way,
sometimes kicking it to a little distance. Once
in every two or three trips they would come
out far enough to expose part of the thorax.
They appeared and disappeared with the

regularity of a machine, never stopping to
rest.

BOTTLE ON
STEM TO
MEASURE

We remained with them until seven o'clock, WORK OF

CRABRO

when we placed a long bottle over each stem
in such a way that while it did not interfere with the
work of the wasp, it caught the chips of pith as they

107

WASPS, SOCIAL AND SOLITARY

fell out. At the end of an hour we noted the amount
of accumulation in the tube, and thus had a measure
of their rate of work. The drawing gives an idea of the
arrangement of the tube on the stem. When we left
them they were still digging and delving.

At half past nine we took a lantern and went down
to visit our charges. We expected to find them at rest,
and asleep; but on the contrary they were working as
busily as ever, and upon examining the measuring
glasses we found that they had not paused since we
left them. We measured the depth of the debris in the
bottles, and then emptied them.

At four o'clock on the next morning we went to the
garden, and were much surprised to find that the two
wasps had worked without intermission throughout
the night. Indeed they seemed to have shortened a
little the time that it took to make a round trip down
the gallery and up to the opening again, since there
was more pith in the bottles than we could have ex-
pected if they had worked at only their former rate.
Neither the coolness of the air nor the darkness of the
night had made the slightest difference to them. After
watching them a few minutes, and marveling at their
powers of endurance, we cleared out the tubes and
returned to bed. At half past eight we found them still

1 08

CRABRO

at work. Unlike us, they had taken no morning nap,
but had gone on with their tunneling in their usual
steady way.

From this time their ways diverged, and they must be
described separately. At nine o'clock the one that we
had first seen came up to the opening, walking head
first, and flew off, remaining away seven minutes. When
she returned she at once resumed her work, and kept
at it without a pause until two in the afternoon. At this
hour she went away, and we never saw her again. We
suppose that she was killed, for it seems improbable
that so faithful a creature could have deserted her half-
finished home. Pompilus quinquenotatus often deserted
a partly finished nest for some more enticing spot, and
Sphex started several excavations before making a final
choice; but we cannot believe that there was anything
fickle about Crabro.

The second wasp came up head first to the entrance
of her hole at two minutes after nine, as though she
had been influenced, in some subtle way, by her neigh-
bor's example; but after looking about for a moment
she went back. She repeated this observation several
times, and finally, at twenty-five minutes after nine,
came out and flew to a leaf near by. Then she cir-
cled around, alighting a number of times, and at last

109

WASPS, SOCIAL AND SOLITARY

departed. Her stay was brief, for at just thirty-five
minutes after nine she returned, and at once settled
down to her work.

We now began to make notes as to the length of time
that it took her to go down and bring back her load. We
timed her again and again, and found that she was
remarkably regular, each of her trips occupying from
forty-five to fifty seconds.

All that day we kept her under strict surveillance, and
never once did she suspend her operations either for rest
or refreshment. Late in the afternoon, while we sat
watching her as she appeared and disappeared with
almost the regularity of clockwork, we found it difficult
to realize that the patient little creature had been at
work for more than twenty-four hours, with only one
brief intermission. Without hurry or flurry she kept at
her task, reminding us, in her business-like ways, of the
social wasps of the genus Vespa. When we left her,
at dusk, we attached the recording tube to the stem,
and at ten o'clock in the evening we found that she
had not stopped working. We emptied the glass, and
left her.

At seven o'clock in the morning of July twenty-ninth
we paid her a visit, and could scarcely believe the testi-
mony of our senses when we saw that the record was one

CRABRO

of unceasing toil through the long hours of the second
night. We began to wonder if she would ever finish her
task. Wonderful though she was, we had grown a little
weary of our long session of watching. We had been
glad that she worked through the first night; it was
creditable to her and interesting to us, and we admired
her even more for sticking to it through the second, but
when it looked as though we might have to remain by
her side through another long day, watching an endless
series of loads as they were carried out, we confess that
we thought she was rather overdoing it. Gradually,
however, she slowed up her work, taking two or three
minutes to make a journey down and up. At last, at just
nine o'clock, her head appeared at the top of the stalk,
and after a slight hesitation she flew away. The nest was
completed.

We have studied wasps for a number of years, and we
feel that we are on terms of more or less intimacy with
many of the species, but never before have we known
one to work after day was done. We have often gone
out with a lantern at bedtime for a tour of inspection
among our nests, and have always found the inhabitants
quiet and presumably asleep. The social wasps are very
industrious, but during the hot nights of July they are
to be seen clustered together on the outside of their paper

WASPS, SOCIAL AND SOLITARY

nests in deep repose ; and although the Vespa wasps that
nest in the ground sometimes come home late in the twi-
light, we have never seen them work after it was really
dark. Polistes fusca may be said to share our cottage,
so thickly does she hang her combs under the shelter of
our porches, and from observations taken at all hours
we know that she is quiet through the night. Sir John
Lubbock, in "Ants, Bees, and Wasps," speaks of the
great industry of wasps. He has known them to work
from early morning until dusk without any interval for
rest or refreshment; but here was our little Crabro
toiling from three in the afternoon of July twenty-
seventh, through that night and the day and night fol-
lowing until nine o'clock on the morning of the twenty-
ninth, — a period of forty-two consecutive hours with
one intermission of ten minutes on the morning of the
twenty-eighth. Surely she takes the palm for industry,
not only from other wasps, but from the ant and the bee
as well.

The nest was completed, but the work of storing it
remained to be done. The wasp flew away at nine
o'clock, and ten minutes later came back with some-
thing, we knew not what, for she dropped into her hole
so quickly that she was out of sight almost before we
knew she was there. Two minutes later she came up,

112

CRABRO

and was off again. This time she was gone twelve min-
utes, and when she returned we were again baffled in
our effort to see what she was carrying. When she came
out she alighted upon a leaf and attended to her toilet,
cleaning both body and wings by rubbing them off with
her hind legs, and from this time on she never started on
a hunting expedition without paying
this attention to her personal ap-
pearance. On her third trip she was
gone twenty minutes, coming back
with a small fly; and before we left
her at ten o'clock, she had stored six
more. When we came back at half
past two in the afternoon she was
working, and she kept up her go-
ings and comings until four o'clock,
when she suspended operations for
the day. On the next morning we
were called away, and know nothing
of what she did, but on the follow-
ing day, Thursday, we resumed our
observations. She worked hard all the morning, but
in the afternoon her trips were few, and were made
at long intervals. On Friday she worked from eight
to nine, when she departed, and never returned. We

NEST OF C. STIRPICOLA

WASPS, SOCIAL AND SOLITARY

watched for her, at intervals, all through that day and
the next, when we were forced to conclude that our
faithful little worker had fallen a victim to some bird
or beast. We did not disturb the nest until four days
later, when we cut the stalk, and examined it.

We found that the tunnel was thirty-nine centimeters
in length. This was a long distance for her to excavate,
and, all things considered, her progress had been rapid.
We have opened a number of stems that had been stored
by this species, and all the excavations were from thirty
to forty centimeters in length, the width of the gallery
being about three and one half millimeters, while on each
side there was from one to one and one half millimeters
of pith that had not been cut away. Of course these
points varied with the diameter of the stem and also
with the size of the worker.

Our little stirpicola had stored one cell, had laid an
egg, and had built a partition of pith across the stem as
a floor to the second cell, before her untimely taking off.
Had she lived, ten or twelve cells would have been stored,
one above the other. The completed cell contained a
larva and parts of eighteen flies of different sizes, four
species being represented. The flies had all been at-
tacked by the larva, the abdomens of some and the tho-
races of others having been eaten. The larva continued

114

AMMOPHILA SLEEPING IN THE GRASS (AFTER BANKS)

CRABRO

to eat for two days, and then spun its cocoon. The flies
found in this and in other nests of stirpicola were all
dead. All the pupae that we kept wintered in the cocoon
and came out in the spring.

The females of Crabro, like those of other genera,
seem to use their galleries as sleeping places, but the
males stop at any convenient inn. We once entertained
one of them for several nights in a hole in one of the
posts of our cottage porch. Other males, as in Philan-
thus, spend time and care in digging a hole in the ground,
to which they return night after night. In Agenia the
female keeps one cell ahead of her needs, and tucks her-
self away in it very comfortably ; but the Pelopaei, in-
stead of making this use of their tubes, congregate in
the evening where there are convenient crevices, and
make as much fuss about getting settled as a lot of Eng-
lish sparrows. Mr. Banks has made a delightfully pretty
as well as interesting observation on the sleeping habits
of Ammophila. In a corner of his garden where the
grass grew long, dozens of these wasps arrived every
evening, and after a good many changes in position,
fell sound asleep, clinging to the stems about one third
of the way down. They registered at this hotel between
seven and eight o'clock, and departed before five in the
morning. We have seen a Pompilus take the greatest

117

•

WASPS, SOCIAL AND SOLITARY
care in selecting a sheltered spot under some leaves,

•x

where she afterward hung herself up, and slept soundly
until after eight the next day; and Mr. Brues has found
companies of Priononyx atrata passing the night on the
stems of sweet clover.

Chapter VI

AN ISLAND SETTLEMENT

OUR children often made themselves useful by re-
porting finds in the shape of nests, and one day
they returned from the island with a wonderful tale of
great numbers of big wasps that were digging in the
ground. "I don't know what they are," said the small
boy, "but they act to me like the maddest kind of hor-
nets." With this attractive picture before us, we lost no
time in going over to the spot, where we found a thriving
colony of Bembex spinolas. On our approach they fell
upon us, " desire of blood, and rage, and lust of fight" in
their mien, and chased us to a distance, but without in-
flicting a single wound. This temperance was not due to
gentleness of disposition, but to the fact that Bembex is
not at all handy with her sting, her body being too large
and clumsy to curve and give the lightning stab as other
wasps do. With renewed courage we again approached
them, more cautiously this time, and soon learned that
if we preserved an extremely composed and dignified
demeanor our presence on the field would be tolerated.

119

WASPS, SOCIAL AND SOLITARY

Bembex, like Philanthus, and some species of Sphex,
lives in a sort of semi-social state, a number of individ-
uals occupying the same space of ground, although each
one has its separate nest. Bembex, however, differs
from these genera and from almost all of the solitary
wasps in her habit of feeding her young from day to day,
or rather from hour to hour, as long as it remains in the
larval state. This difference in her maternal cares as
compared with those of other species results in a less
numerous progeny. The larva, for a period of two weeks,
demands constant attention from the mother, so that a
second egg cannot be laid until the first-born has gone
into its cocoon, unless, indeed, she feeds two larvae at
once, which does not seem probable. The season of
work is ten or twelve weeks, so that Wesenberg is prob-
ably correct in allowing only five or six young ones to
each mother for the summer.

In watching our wasps we found that the new nests
were usually made in the outskirts of the colony, which
was thus continually extending its limits. Like many
other species, Bembex has great difficulty in deciding
just where to dig. Our Sphex made three beginnings
before finally settling down. The only Ammophila that
we watched from the beginning changed her place after
working for ten minutes. P. quinquenotatus often tried

1 20

AN ISLAND SETTLEMENT

half a dozen places before she was satisfied, and spinolae
is quite as difficult to please.

When, at last, the right place is found, the labor of
excavation is carried on vigorously. The mandibles are
used for loosening the earth, and for lifting, but the
greater part of the work is done with the first pair of legs,
the tarsi of which are doubled up while the dirt is swept
out with the brush of stiff spiny hairs on the second joint.
This attitude gives them a very comical aspect, making
them look as if they were sweeping with their elbows.
They sometimes lie far over to one side while loosening
the earth with their mandibles. While digging, the body
is held high by the straightening of the third pair of legs,
and the dirt comes out behind in a rapid stream, flying to
a distance of three or four inches. Before long the wasp
is lost to sight, but every few moments she comes back-
ing out, pushing behind her the dirt that she has dis-
placed below. In about fifteen minutes the nest is ready,
and the wasp turns her attention to scattering all the
dirt that has been thrown out, sweeping the ground
clean so that no sign of her work remains. We have
often speculated as to the meaning of the careful and
conscientious performance of this part of her task. With
the wasps that nest by themselves it is not easy to see
what enemy they are providing against in hiding the

121

WASPS, SOCIAL AND SOLITARY

entrance to the nest ; but the precaution seems still less
necessary- -even absurd — in the Bembex field, where
there is no possibility of concealing the colony, and
where the nests are only an inch or two apart, so that
an enemy might burrow anywhere with the certainty of
finding one. Moreover, the only enemy that we could
discover was the parasitic fly, which never attempts to
enter when the hole is closed. However, unmoved by
our opinion on the subject, spinolae spends five or six
minutes of her precious time in making the neighbor-
hood of her home quite tidy, and then she fills in the
mouth of the nest with a little loose earth before going
away to catch her fly.

Oxybelus, though she is limited in choice by her small
size, can catch a fly in three or four minutes. Bembex
is strong enough to take anything that she sees, and she
has no preference for one species above another, yet she
seldom finds one under twenty or twenty-five minutes.
When she comes back nothing of the fly is visible unless
it is unusually large, so closely is it held under her body
by the second pair of legs. She alights, and scratches
away the loose earth at the entrance of the nest with her
first legs, and then, as she creeps within, she passes the
fly along from the second to the third pair, so that the
end of its body, projecting beyond the abdomen of the

122

AN ISLAND SETTLEMENT

wasp, is visible for an instant before it is carried inside.
Sometimes she drops the fly behind her, and then, turn-
ing around, pulls it in with her mandibles. In other
cases, where a longer portion of the tunnel has been
filled with earth, the fly is left lying on the ground while
the wasp clears the way. This offers a favorable oppor-
tunity to parasites, especially as the fly is not placed with
regard to its safety, but is dropped anywhere. The dirt
that is kicked out sometimes covers it so that when the
way is clear the careless proprietor must search it out and
clean it off before she can store it away. In one instance,
in which we had been opening a nest close by, the tunnel
was entirely blocked by the loose earth which we had
disturbed, and the wasp worked for ten minutes before
she cleared a way to her nest. During part of this time
she held the fly, but when she realized that it was going
to be a long piece of work she laid it down near by. As
the wasp enters she sometimes leaves the hole open be-
hind her, but oftener fills it by pushing up earth from
below. When she comes out again she throws in a little
dirt, and then begins to circle about the place. She
seems not quite easy about the nest, however, returning
three or four times to scratch earth over the entrance,
before finally taking her departure.
We opened a good many nests in the course of the

123

WASPS, SOCIAL AND SOLITARY

summer, and found them all very much alike, much
more so than is the case with other species. The en-
trance tunnel runs in obliquely for from three to five
inches below the surface of the ground, and ends in a
pocket.

We grow accustomed to marvels, and from our famil-
iarity with other wasps we take as a matter of course the
unerring accuracy with which Bembex swoops down
upon the exact spot at which the entrance to her nest is
hidden. And yet how strange a power it is ! There is not
the least sign to help her - - not a stone, not a blade of
grass is to be seen on the field. Our method of marking
a nest which we wished to find again was to place tiny
pebbles at exactly equal distances from it, one on either
side, so that the middle point of the straight line between
them gave us the desired spot; and the wasp doubtless
uses the same method, only her landmarks are some-
times so infinitesimal that we do not recognize them.

Bouvier finds that when he cuts away the plants
around the nest of B. labiatus, clearing a space of
twenty- eight or thirty inches square, the wasp is much
confused, flying about for a long time before she is able
to find her home. He once placed a flat stone over the
entrance. The wasp alighted upon it, and after scratch-
ing vainly for a while made her way in. The stone was

124

AN ISLAND SETTLEMENT

left in this position for two days, during which time
Bembex learned to regard it as a landmark, for upon
its being removed to a distance of eight inches she still

. —

'"• '^— ^ ' "«-T%. ^*z=*~ - a^.- - - to. '*• .

NEST OF BEMBEX

followed it upon returning with her fly, and insisted
upon finding her nest near it.

An observation of Marchand points to the same con-
clusion. He says:-

On July seventeenth, 1900, during a short sojourn at
Pouliguen, on returning from a hunt after Diptera and Hy-
menoptera in the cliffs of Caudan, about eleven in the
morning, in tropical heat, I paused to take breath near
the old mill of Caudan and looked about for a little shade

125

WASPS, SOCIAL AND SOLITARY

before continuing my walk to Pen-Chateau. I had seated
myself on the stones of a slope shaded from the sun and
was wiping the perspiration from my forehead, when I
saw a large wasp arrive directly before me. I instinctively
followed it with my eyes ; it paused some yards from the
mill on the side of the cliff, and began to open a nest
which was placed scarcely twenty inches from the foot of
a swallow-wort, a rather common plant in the neighbor-
hood of the ruin. She was Bembex rostrata at work at
provisioning her nest.

Moved by curiosity, instead of going on to breakfast, I
awaited the exit from the nest, which took place in about
five minutes. Bembex scratched the sand and took flight
from the side of the cliff. How long would she be away?
I looked at my w-atch and arose.

Ought I to go or to wait a little while ? I took the latter
decision. Out of malice, and without any idea of trying a
control experiment to the admirable observations which
science owes to the naturalist of Se'rignan, of whom I was
not thinking at all, I cut close to the sand the stalk of the
swallow-wort and planted it a little nearer the mill, moving
it about two feet, and being careful to put in place of the
plant a little fragment of a bottle which I found in the mill.
I seated myself in the shade and waited. Twenty minutes
later the wasp dropped straight on to the place where I had
cut the plant, that is to say, it deviated from its nest by a
distance about equal to the displacement to which I had
subjected the swallow-wort. It walked right and left, agi-
tating its antennas, appearing confused as to the locality.

126

AN ISLAND SETTLEMENT

I followed these goings and comings for two or three
minutes. Several times it flew away and then returned,
always searching about. Pitying it and desiring, since I
was now relieved of the fatigue which the heat had caused
me, to go back to breakfast, I took my net and drawing
near, made as if to catch it, swinging the pocket rapidly
about. It veered away with a quick jerk of the wings. I
then took up the swallow-wort, lifting the fragment which
marked its original place, and replanted it in the sand.

I again looked at my watch to see whether I could con-
secrate yet a few more minutes to curiosity without mak-
ing my kind host, my friend Dr. MCi; Rivron, and his wife,
who honored me with the charming hospitality of Kursac,
wait too long. It was only half past eleven ; we usually
did not breakfast until about noon; it would take only a
quarter of an hour to traverse the distance from the mill
of Caudan to the house. I could then, without fear of be-
ing chided, dispose of fifteen minutes. This lapse of time
would perhaps suffice to show me whether my bestiole would
this time find the way to her nest without hesitation.

I waited a little; five minutes had not passed when my
Bembex, coming like an arrow, alighted on the sand near
the plant, still holding the prey which I had noticed when
she departed at my chasing her, after her vain attempts to
find the entrance to her nest ; but this time she did not
hunt long. She felt about a little to right and left, but
soon turned directly toward the entrance to the tunnel,
distant scarcely two inches from the place where she had
settled. My Bembex had a memory.

127

WASPS, SOCIAL AND SOLITARY

A curious thing about these wasps, and one which
shows how much common feeling they have, is that they
work in waves, all starting off on their hunting expedi-
tions within a few minutes of each other, and returning
together after the chase. At one time all the residents
seem to be present, digging their nests, carrying in their
booty, dashing at each other, and chasing the parasites
with a tremendous amount of humming and swooping
about. Then suddenly they are all gone. Nothing re-
mains but multitudes of flies, which keep up a giddy
dance over the field, and for ten or fifteen minutes the
place seems deserted. Then the wasps begin to return,
several coming at a time, and as if by magic the whole
scene awakens to life. More than half of the wasps bring
nothing home with them, and these fall to robbing their
more fortunate companions. Those that are carrying
flies must pause a moment, burdened as they are, to
scratch away the earth at the entrance to the nest. When
unmolested they go in very quickly, but it is just at this
point that the marauders fall upon them, displaying an
amount of persistence and energy in their attacks that,
were it properly directed, might easily enable them to
secure flies for themselves.

We once saw a wasp that had been fortunate enough,
or perhaps unfortunate enough, to catch an immense

128

AN ISLAND SETTLEMENT

fly, the wings of which stood out on both sides very con-
spicuously. This made her an especial mark for her
unprincipled relatives. Half a dozen of them chased her
about, like chickens pursuing one of their number that
has found a worm. She circled and settled, and circled
and swooped around for five or six minutes, continually
pursued and attacked by the robbers, and quite unable
to get into her nest. At last, curious to see what she was
carrying, we made her drop her load, and secured it for
ourselves. We found it to be a horse fly, quite dead, but
showing no marks of violence. It was not wasted, for
we afterward fed it to one of our wasp nurslings at home.
At another time we saw one wasp attack another that
was bringing in a fly. In the struggle that ensued the
owner lost her booty, as the two rolled over and over on
the ground, and as they parted it was seized by the thief.
They clinched again, and rolled on the ground as before,
and this time the fly was recovered by the rightful owner.
At this point, thinking that perhaps one of the wasps
was a male, and that this might be their style of court-
ship, we seized both of them; whereupon the fly was
dropped, and the two wasps turned their attention to
attacking us. Both proved to be females. Not only do
the Bembecids fight in this way for the possession of
their prey - - they quarrel even without apparent cause.

129

WASPS, SOCIAL AND SOLITARY

We have seen two females digging their nests at a little
distance apart, one of which was repeatedly attacked by
the other, although she did nothing to provoke the ag-
gressor. They are certainly very unneighborly, and have
no idea of living in harmony. When flying in a threaten-
ing manner, either at us or at each other, they have a
way of wagging their abdomens violently from side to
side in a way well calculated to inspire terror.

In warm sunny weather spinolae works industriously
through the middle of the day, and seems determined to
provide abundantly, not only for her own offspring, but
for any unbidden guests that it may be her fate to care
for. She never works more than four or five hours a day,
however, and in unfavorable weather she does not work
at all. On going over to the island one cloudy morning
to spend some hours in watching the Bembex activities,
we found the spot quiet and lifeless. No one seeing it for
the first time would have dreamed of the multitudes of
living creatures beneath his feet. The nests seemed to
be all closed, but on peering curiously about we found
one on sloping ground, in the suburbs of the colony, of
which the door was open. Just within was the proprietor
gazing out on the landscape, as she is shown in the illus-
tration. She seemed to be leaning on her elbows, and
her face, enlivened by two great goggle eyes, had an

130

AN ISLAND SETTLEMENT

irresistibly comical aspect. With the exception of the
omnipresent flies, this wasp was the only sign of life
about the place. Even in good weather, and in working

BEMBEX SPINDLY LOOKING OUT OF NEST

hours, the wasps sometimes rest, for we have seen them
go in empty-handed, closing the door behind them, to

remain for half an hour at a time.

There is one thought that must strike even a casual
observer at the sight of the hordes of parasites that
hover over a Bembex colony: -

WASPS, SOCIAL AND SOLITARY

" The buzzing flies, a persevering train,
Incessant swarm, and chased return again."

Why do not these wasps, fly-catchers as they are by pro-
fession, kill the worthless wretches that infest their
homes, thriving abundantly on the fruits of their labor,
a continual menace to the life and safety of their off-
spring ? To the uninitiated it would seem that these flies
might serve as food for the wasp larvae quite as well as any
of the dozen species that they actually take ; but even if
the wasp-mother believes that they possess indigestible
qualities, it would be much less trouble to kill them and
throw them away than to be perpetually chasing them
to a little distance only to see them return as soon as
she gives her attention to anything else. Whatever the
reason for it may be, the relation between the wasps and
the flies is certainly most curious and puzzling. Fabre's
explanation is that since this miserable little fly has its
own part to play in nature, Bembex must respect it,
thus preserving harmony in the world of living things.
The idea is perfectly in accord with his own theories,
but we find ourselves quite unable to accept it.

There can be no doubt that the parasites are a grave
danger to Bembex. She suffers from them far more than
any other wasp that we are familiar with, her mode of
feeding the young rendering her peculiarly susceptible

132

AN ISLAND SETTLEMENT

to their attacks. Of the ten or twelve nests that we
opened only one was free from them, the others con-
taining from two to five lively maggots nearly as large
as the wasp larvae, which were sharing the food brought
in by the mother. Fabre, who has studied the question
thoroughly, has found as many as ten parasitic larvae in
one nest. He has also noticed that where the parasites
are most numerous the wasp-larva is proportionately
small and emaciated, reaching only one half or one third
of its normal size. When it attempts to spin its cocoon
it has not strength enough to do so, and thus perishes
miserably among the pupae of the interlopers, which have
the advantage of developing more rapidly. He has proved,
by experiments upon nests transported to his study, that
although the invaders preserve friendly relations with
the rightful owner of the nest so long as food is abun-
dant, they nevertheless, at the first suggestion of scarcity,
fall upon the wasp larva and ruthlessly devour it. This
'black action" he has seen with his own eyes. In view
of this base ingratitude, we are more than ever impressed
with the troubles of the poor Bembex mother, as she
tries to feed a dozen mouths where she has bargained for
only one.

We several times saw a fly follow a wasp into her nest,
remaining within for half a minute, and it is probable

133

WASPS, SOCIAL AND SOLITARY

that they go in to lay their eggs. According to Fabre, it
is the habit of the flies that are parasitic upon the half-
dozen species of Bembex that he has studied to seize the
moment at which the fly projects from under the abdo-
men of the wasp as she enters the nest ; and he has even
known them to lay two or three eggs on one fly in the
instant of time that its body was exposed.

Fabre took a partly grown Bembex larva from the
nest, where it was surrounded by the remains of twenty
flies. He fed it generously, and it ate sixty-two more,
making a total of eighty-two in the eight days that
passed before the spinning of the cocoon. Our experi-
ments in this line gave similar results. We took charge
of a partly grown larva on the afternoon of August tenth,
and between that date and August fifteenth, when it
spun its cocoon, it ate forty-two house flies besides a big
Tabanus.

Fabre thinks that under natural conditions the mother
does not give the larva all it can eat at one time, but pro-
vides it with what she considers a reasonable amount of
food, and keeps anything that she catches beyond this
out of its reach. He draws his conclusion from the fact
that he has found several flies in the tunnel leading to the
nest, while the larva had as many more close to it. It
would certainly be convenient for Bembex to have a

134

AN ISLAND SETTLEMENT

reserve of this kind in case of rainy weather, but the
forethought implied in such an action seems to require
a higher degree of intelligence than can be claimed for
her.

In one nest we found a single fly with a long cylindri-
cal egg attached to the left side of the thorax just at the
origin of the third leg. In another, which we had seen
made and provisioned, we found, six days later, a larva
which we judged to be four days old. Assuming that the
egg was laid on the first day, it must have taken it about
two days to hatch. Other nests gave us larvae in all
stages of development, surrounded by the remains of
Diptera, among which Syrphus, Tabanus, and Musca
were represented.

In regard to the condition of the flies captured by
Bembex, we have never seen the crushing of the thorax,
which is noted by both Wesenberg and Fabre. Indeed,
the flies that we found were not always dead, since in
two instances they responded readily to stimulation.
Similar results have been obtained by Mr. S. W. Dun-
ning of Hartford, Connecticut.

Twice we have seen our spinolae, as she was bringing
home her prey, alight near the nest and sting it as it was
held with the second pair of legs. We could see the pro-
cess distinctly, since she is slow and clumsy, and, in jon

135

\^«.
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WASPS, SOCIAL AND SOLITARY

instance, had difficulty in reaching the fly, falling over
to one side in an awkward manner. It is probable, then,
that this is a habit with the wasp, but that the sting is
usually given at the place of capture.

We opened a number of Bembex nests, but succeeded
in raising only one larva, which we took when it was half
grown. This one, during the five days that passed before
it spun the cocoon, ate forty-three flies.

Mr. Bates has some notes on Monedula signata, which
takes nothing but flies, and even confines itself to a single
species, although it must sometimes go half a mile away

BEMBEX

to find it. This reminds us of Pompilus quinquenotatus,
which never takes anything but Epeira strix.

A considerable contribution to our knowledge of the
genus Bembex has been made in the paper by Wesen-

136

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A CORNER OF THE BEMBEX COLONY

AN ISLAND SETTLEMENT

berg (written in Danish) which has already been referred
to. This paper deals with Bembex rostrata. It was trans-
lated for Mr. Ashmead by Mr. Martin Linell.

It seems that rostrata makes its nest in solid sand,
covering it up with loose sand, and usually, also, with a
little flat stone, to prevent parasites from entering. The
cell measures one cubic inch, the entrance tunnel being
one and one half centimeters long, and arcuate. A cell
contains four or five fresh flies (Lucilia, Eristalis, etc.),
and torn-off wings, sucked-out thoraces, and in the mid-
dle of these, a big flat larva.

When the larva is hatched the mother brings more
and more flies, the flies being larger and larger as it
grows. This adjustment of the size of the fly to the
growth of the larva has also been noted by Fabre.

Wesenberg says that fifty Bembecids will nest on a
spot as big as a room during a period of three months.
The time required for the development of the larva is
two weeks, this giving five or six young ones for the
season. He queries, " Does each female have more than
one nest? and if so, how can she remember them?"
To determine this point we marked six wasps by touch-
ing them with differently colored paints, putting near
their nests pebbles painted to correspond with the
owners, and then watched them closely for three hours.

139

WASPS, SOCIAL AND SOLITARY

During this time the red wasp returned regularly to the
red nest, the blue to the blue, and so on. They were
watched for an hour and a half on the following day
with the same result, so that it seems quite certain that
spinolae has only one nest at a time. To feed two larvae
at once, with interlopers thrown in, would be a heavier
task than the most determined industry could accom-
plish.

Chapter VII

THE BURROWERS

DUFOUR, in describing the fearful ravages of Cer-
ceris ornata among the bees, says that the wasps
of this genus are among other insects what eagles and
hawks are among birds. While this characterization
does not seem to fit the American species, it is certainly
true that the genus stands out as one of those in which
the distinctive peculiarities are strongly marked. They
might be considered the aristocrats in the world of wasps,
their habits of reposeful meditation and their calm, un-
hurried ways being far removed from the nervous man-
ners of the Pompilidae or the noisy, tumultuous life of
Bembex. Their intelligence is shown by their reluctance
to betray their nests, and by their uneasiness at any
slight change in the objects that surround them. It is
not necessary to attempt to catch them or to make
threatening gestures, in order to arouse their sense of
danger. If you are sitting quietly by a nest when the
wasp opens her door in the morning she will notice you
at once, and will probably drop out of sight as though

141

WASPS, SOCIAL AND SOLITARY

she resented your intrusion into her privacy. After a
little she will come up again and will learn to tolerate
you, but at the least movement on your part, almost at
the winking of an eyelid, she will disappear.

Our four representatives of this genus all prey upon

beetles that are injurious to
vegetation, and therefore de-
serve the gratitude of agri-
culturists. Nigrescens, with
her pale grayish bands, is a
very trying wasp to deal with.
We had seen her flying about
in the garden for weeks be-
fore we succeeded in track-
ing her home, and when we
did succeed she was so late
about getting up in the morn-
ing, stayed away from home
so many hours at a time, and
went to bed so early in the
afternoon, that we were not
well repaid for watching her

NEST OF CERCERIS NIGRESCENS

nest all day. Fumipennis,
large and handsome, with a broad yellow band at the
front of the abdomen, is another wasp that has no

142

THE BURROWERS

regard for the convenience of the people who are watch-
ing her. You may sit by her big open hole for hours
without seeing her, and when she comes she drops in
so suddenly that, unless you are very much on your
guard, you are not sure even then what she is. Clypeata
and deserta are better subjects for study.

The nests of our species are all deep, tortuous, and
very difficult to excavate. We have never succeeded in
finding their pockets;
and yet, for various
reasons, we feel per-
fectly certain that all
of them are like C.
ornata in provisioning,
successively, a number
of cells which lead out
of the main gallery.

When one of these cells is filled with food, and the egg
deposited, it is probably closed up, and thus separated
from the runway. From our experience late in the
season with the nests of another wasp, we are inclined
to think that we made a mistake in looking for pock-
ets at the lower end of the tunnel. Had we searched
higher up, at the point of the curve, we might have
found them, the lower part of the gallery probably being

143

CERCERIS CLYPEATA

WASPS, SOCIAL AND SOLITARY

designed merely for a dwelling-place for the mother of
the family.

But although we did not get distinct pockets, there
was, in at least one nest, a supply of food that would
have far exceeded the wants of a single larva. We
did not succeed in finding eggs on different groups of
beetles ; but from a nest into which the wasp was still
carrying food we took a half-grown larva which was
identified as being hers. The fact, too, that a wasp occu-
pies a nest for so long a time as ten days or two weeks
points to the conclusion that she uses it for a number of
eggs which are laid at intervals.

Cerceris digs her nest, deep as it is, all at once. In
this she is a contrast to her near relatives of the genus
Philanthus, who busy themselves for an hour or so every
morning with fresh excavations.

On the eighth of July the weather was so warm and
bright that we went down to the garden at half past
eight o'clock, knowing that it was rather early, but
hoping that the hot sunshine would tempt the wasps
to industry. We had walked up and down several times,
when suddenly, right in the pathway, a nest appeared.
A great quantity of loose earth had been taken out and
heaped up, probably on the preceding day, and in the
midst of this a little hole had been opened since we

144

THE BURROWERS

passed before. The place looked so promising that we
sat down to watch it, and a few minutes later we were
rewarded by a glimpse of some antennse down the gal-
lery, and then a little face with yellow markings appeared
but quickly vanished. Now followed a very coquettish
performance. The wasp came slowly creeping up again
and again, only to drop out of sight as soon as she had
reached the opening. After a time she grew bolder, and
sat in her doorway, twitching her head this way and
that in a very expressive manner, as though she were
planning the work of the day; but it was plain that
although she was up early, business cares were not
weighing heavily upon her mind, for forty minutes
passed before she came out of the nest, and after making
three or four circles about the spot, flew away.

How much livelier and more interesting it would have
been if we could have followed her! We tried to guess
at what she was doing, and imagined her hunting in-
dustriously. After fifteen or twenty minutes it seemed
to us that she must have caught something, and that
she was surely returning. Most probably she was not
working at all, but was breakfasting leisurely and ex-
changing compliments with her neighbors ; for when she
did come home after keeping us waiting for an hour
and a half, she brought nothing with her, and seemed

145

WASPS, SOCIAL AND SOLITARY

quite unconscious of the fact that greater things had
been expected of her.

We had placed a stone upon a dead leaf near by, to
mark the neighborhood of the nest, thinking that even a
Cerceris could not object to so simple an arrangement
of natural objects; but our wasp noticed it at once, and
evidently with much suspicion and disapproval. She
began by circling several times just above it. Then she
alighted on it and examined it carefully, walking over
it, and creeping underneath, perhaps to see whether it
in any way menaced the safety of her nest, perhaps as
the completion of a locality study made the day before.
She then rose on her wings, and after a little more cir-
cling, dropped suddenly into her hole.

So far we had not been getting on very rapidly, but
from this time things took a turn. Cerceris is never in a
hurry, and yet she may be relied upon to do a certain
amount of work every day. The one that we were now
watching had probably come back for a final look at her
newly made nest before beginning to provision it; for
she soon reappeared, and this time really went to work,
since in forty minutes she brought home a beetle which
she carried by the snout, venter up, in her mandibles,
supporting it with the second pair of legs while flying.
She was much annoyed at our presence, and circled

146

THE BURROWERS

about as before. Twice she alighted near by, and walked
around for a few minutes, and when she did this all
her feet came down to the ground, the beetle being
allowed to hang loosely. At last she made the best of a
bad matter, and went in. The rest of the morning was
occupied with hunting, the capture of each beetle taking
about forty-five minutes. Every time that she came
home she spent fifteen or twenty minutes in the nest.

This species soon became very common, and for two
weeks scarcely a morning passed without our finding at
least one newly-made nest. The study of clypeata, how-
ever, consumes a great deal of time. For example, we
found, one morning, two nests within six inches of each
other. It turned out afterward that these were inhabited
by two different wasps ; but at the moment we supposed
that one of them had been dug and deserted and then a
second one made, and wishing to know which one was
occupied we resolved to watch and see. After waiting
for three hours we saw one wasp returning; but upon
noticing us she veered off and began to circle about.
She was heavily laden, and her burden, instead of being
supported by the second pair of legs, as is sometimes the
case, hung down under the thorax and abdomen. After
a moment she alighted on a plant near by, and seemed
to consider the situation, then circled a little more, and

147

WASPS, SOCIAL AND SOLITARY

flew away, remaining out of sight for fifteen minutes,
then another return, more circlings and hesitations. She
seemed to feel the weight of the beetle now, and alighted
frequently on the ground and walked about; yet she
would not go in, so reluctant was she to betray her nest.
In this way she kept us waiting for a whole hour,
although we were not very near to her, and were as
still as statues. At last we retreated, and stood as far
back as we could and still keep the hole in view. She
now came closer, and, after hanging poised on her wings
for a moment, dropped into her nest.

We once found a nest of this species in process of con-
struction. A large heap of fresh earth had been pushed
out, which entirely covered the spot; but at intervals
there were upheavals from below which betrayed the
presence of the wasp. When we saw it first it was half
past eight o'clock, and we judged, from what had been
accomplished, that she must have been at work at least
an hour. It was half past nine before the excavation was
complete. We had not been certain, up to this time, as
to what we were watching ; but now we had the pleasure
of seeing her open her doorway from below and stand
in the entrance while she washed her face with her fore
feet, like a cat. When they rest at the mouth of the hole
the first legs, which are yellow, are bowed in a semi-

148

THE BURROWERS

circle on each side of the yellow face, the distal joints
being bent up so that the wasps seem to be standing on
their elbows. This attitude, which is often seen in Bem-
bex spinolse, gives them a delightfully amusing, bow-
legged appearance. They usually open their nests in the
morning at about nine o'clock, - - a little earlier or later
according to the time at which the sun strikes the spot.
Then they spend from forty minutes to an hour in taking
a survey, the least movement on the part of a watcher
causing them to drop out of sight as if the earth had
given way beneath them. Sometimes there is a little
way-station an inch or two within the tunnel, and the
wasp falls back only to this point, and here she may be
seen, if one peeps in cautiously, either quietly awaiting
the retreat of the intruder, or, perhaps, performing her
toilet in a leisurely and elegant manner.

Whenever she leaves her nest she makes three or four
rapid circles around the spot to freshen her memory of
the locality. The most thorough study that we saw
made by clypeata was in the case of the wasp mentioned
before, that was so long in carrying her beetle in because
of our being on the ground. When she finally did go in
she stayed only an instant — just long enough to de-
posit her load - - and then came out and spent a long
time in an investigation of all the surrounding objects,

149

WASPS, SOCIAL AND SOLITARY

flying in and out among the plants, now high, now low,
and circling again and again around the spot. It looked
as though she had been puzzled and disturbed by the
presence of unaccustomed things. As soon as the survey
was over she went inside and closed the door, as though
its object had been not so much to strengthen her mem-
ory as to correct former impressions.

The work of bringing in beetles goes on very irreg-
ularly, and as a rule not more than two or three are
stored in the course of a day. It is not unusual for cly-
peata to spend three or four hours away from home and
then come back without anything ; and often, even in
the middle of the day, she passes an hour or two in the
seclusion of her nest. We had several nests under obser-
vation for a week at a time without ever once seeing the
owners, although they were evidently occupied, since
they were sometimes open and sometimes closed. The
outer entrance is always left open when the wasp goes
away, although possibly access to the pockets may be
barred below; but when she enters she closes the door
unless she means to come out again at once. The closing
is sometimes effected by pushing the earth up backwards,
with the end of the abdomen ; but the hole is rather too
large for this method, and more frequently the wasp
comes up head first, carrying a load of earth in her front

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legs. This is placed just within and to one side of the
entrance, and then more armfuls are brought up, until,
after two or three trips, the opening is entirely filled.

We once captured the wasp in a bottle, as she re-
turned, loaded, to the nest. She dropped the beetle,
but soon picked it up again and stung it vigorously, with
intention, as the French say, first under the neck, and
then further back, behind the first pair of legs. After
this it was dropped while the wasp fluttered about for a
few minutes, but it was then picked up again, and stung
as before. We both saw this operation repeated in
exactly the same way, four different times, with intervals
of five or six minutes between.

In a nest which we excavated after watching it for
nine days, we found nothing until we had gone six inches
down, and at this point the tunnel was lost ; but mixed
with the crumbly earth that we took out of the hole, we
found eight beetles and a half-grown larva of clypeata.
The destruction of this nest was accomplished one
morning, and when we came back to the spot twenty-
four hours later we found that a new one had been made
close by, doubtless by the same individual. We had ex-
pected to find her bringing beetles and dropping them
foolishly on the ground like Paul Marchal's Cerceris
ornata, and were gratified that she showed an advance

WASPS, SOCIAL AND SOLITARY

in intelligence over that species, although to be sure she
would have been still wiser had she chosen an entirely
new neighborhood. Another individual was so much
disturbed by our scrutiny that she dropped her beetle
at the entrance to her nest. She did not pick it up again
and utilize it, although it lay for three days in the dust at
the threshold.

As to the condition of the beetles stored by clypeata :
in the first nest that we opened we found eight, seven of
which were dead, while the eighth, which we had just
seen stung several times, was alive, but died on the fol-
lowing day. The second nest gave us five beetles, all of
them dead and dry. In the other nests that we opened
we found nothing, though we knew that the beetles were
there had we only been skillful enough to discover them.

Of Cerceris deserta, which closely resembles clypeata,
but appears later in the season, we had only a single ex-
ample. We chanced to see her dropping into a crevice
among some lumps of earth, and at first could scarcely
believe that this was the dwelling-place of a wasp, as
there was nothing whatever about it to indicate a nest;
and even after we had removed the rough pieces of earth
above, we could see nothing of the loose material that
must have been carried out.

She was much like clypeata in her manners, with the

152

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same habit of surveying the world from her doorway,
and manifesting the same annoyance at our presence
when she was returning to the nest; but she carried in
more beetles in the course of the day and worked much

CERCERIS DESERTA: LOCALITY STUDY BEFORE
LEAVING NEST

more rapidly. Between nine and eleven o'clock one
morning she brought in five loads, and some of the
journeys occupied only ten minutes.

The first time that she found us sitting by her nest she
circled about for nearly an hour, seeming unable to
make up her mind to enter. At length we withdrew a
little way, but still her suspicions were not entirely

153

WASPS, SOCIAL AND SOLITARY

allayed; and after a further study of the situation she
dropped, not into her own nest, but into a large cricket
hole near by. Taken aback by this manoeuvre, and
thinking that perhaps we had a second individual to
deal with, we stealthily approached, and peering in,
could see the cricket inside, the wasp having slipped
beyond. It did not seem possible that the little creature
could be endeavoring to deceive us, and yet what other
explanation could be offered for her conduct ? We again
took up our distant position, and after ten minutes more
had the satisfaction of seeing the wasp slip out of the
false nest and drop instantly into the true one. After a
little she became quite accustomed to us, and entered
her nest without the least delay.

The prey of deserta is held in the mandibles, and
while we were watching her she did not support it with
the second legs, even when flying.

Philanthus punctatus is a pretty little yellow-banded
species much resembling Cerceris in appearance. The
nest consists of a main gallery with pockets leading from
it, each pocket being stored with one egg and enough
bees to nourish a single larva. When the wasps emerge
from the cocoon they find themselves in the company of
their nearest relatives and in possession of a dwelling-
place, and they all live together for a time before starting

154

THE BURROWERS

out independently to seek their fortunes. On the fifth
of August we discovered on the island a happy family of
this kind, consisting of three brothers and four sisters,
the females, with their bright yellow faces and mandi-
bles, being handsomer than the males. They seemed to
be on the most amicable terms with each other, their
only trouble being that while they were all fond of look-
ing out, the doorway was too small to hold more than one
at a time. The nest was opened in the morning at about
nine o'clock, and during the next thirty or forty minutes
their comical little faces would appear, one after an-
other, each wasp enjoying the view for a few minutes
with many twitchings of the head, and then retreating
to make way for another, perhaps in response to some
hint from behind. Then one by one they would come
out, circle about the spot, and depart, sometimes leaving
one of their number to keep house all day alone. They
usually left the hole open; but when there was a wasp
within, it was soon closed from below. During this
playtime period they did not return until they were
ready to settle down for the night, the first one coming
home at half after two or three o'clock, and the others
arriving at intervals, none of them staying out later than
five. Most commonly they found the right spot without
trouble, scratched open the hole, and then either closed

155

WASPS, SOCIAL AND SOLITARY

it behind them or stood waiting in the doorway for the
next arrival; but occasionally they had difficulty in locat-
ing the nest, and worked at two or three different places
before finding it.

We kept these wasps under close observation, often
watching the nest from the moment it was opened in the
morning until it was closed at night. On the twelfth of
August, a week from the time that we first saw them,
one of the females felt the responsibilities of life settling
down upon her. At half after four in the afternoon she
began to enlarge the nest, and worked with a great deal
of energy for forty minutes. After a long disappearance
within the hole she would come up backwards, kicking
behind her a quantity of earth which was not only taken
outside, but was then spread out far and wide. She
worked with the front pair of legs, which were curved
inward, after the manner of Bembex; and when a pebble
or some such object came in her way she either dragged
it to a distance with her mandibles or pushed it before
her with her head in a way quite peculiar to herself. In
distributing the earth that was taken out, she went five
and one half inches from the nest - - a distance which
is much greater than is common among wasps, but
which accords well with the habits of punctatus, since
she continues the work of excavation from day to day.

156

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PHILANTHUS PUNCTATUS

On August thirteenth, at half after eight in the morn-
ing, we found that a second female, perhaps inspired by
the example of her sister,
had made a new nest
within two inches of the
first one, and had flown
away, leaving it open.
Presently the other wasps
began to appear, one after
the other, in their door-
way. Two of the males
flew away, and one of the females, doubtless the one
that we had seen digging the night before, began to
work afresh at making the nest larger. Probably she
was excavating a pocket for the reception of an egg,
and the amount of labor required was ernormously in-
creased by the great length (about twenty-two inches)
of the main gallery by which the displaced earth must
be carried out. She worked for an hour, and in spread-
ing the dirt about, inadvertently filled in the opening
of the second nest. At length she flew away.

At ten o'clock a female arrived carrying a bee, and
tried to find nest No. 2. She came to the wrong place,
and worked about, here and there, for some minutes,
holding the bee under the thorax, clasped by the second

157

WASPS, SOCIAL AND SOLITARY

pair of legs. Being unsuccessful, she dropped her burden,
and flew away for a few minutes. While she was gone
we removed a leaf that had fallen over her nest, and on
her return she at once descended upon the right spot,
and began to scratch open the entrance, the bee being
kicked backward with the rejected earth. When the
way was clear, however, she picked it up, brought it
toward the hole, dropped it, ran in and out, brought it
nearer, ran in again, and turning around in the tunnel,
seized the bee in her mandibles and pulled it down. This
performance was due to the accidental obstruction of
the gallery, for we afterward found that punctatus
ordinarily flies directly into her nest, or, when it is
closed, pauses on the wing to scratch an opening with
the first legs. The bee is pushed backward a little as
she goes in, but does not often project from under her
abdomen.

At fifteen minutes after ten the worker from nest No. i
brought in a bee, and from that time the two worked
industriously. They showed some individuality in their
ways, for No. 2 always closed her door when she went
away, and never circled at all, while No. i invariably
circled before leaving, and always left her nest open.
To be sure, there was a female left on guard, so that per-
haps she did not feel the need of caution.

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THE BURROWERS

Our wasps had not far to go for their victims. Forty
feet away, on the eastern side of the island, was a steep
declivity, and here, in the soft crumbly soil, was a great
Halictus settlement. No prettier sight can be imagined
than is presented by this colony on every sunny summer
day. The whole bank is riddled with nests, and at the
entrance of each stands a female bee, her tiny head ex-
actly filling the opening. The bees are constantly arriv-
ing, laden with pollen, whereupon the sentinels politely
back inward to make way for them. Into this scene of
contented industry descends the ravaging Philanthus,
taking guards and workers alike.

On the afternoon of the fourteenth of August our two
wasps were in the full tide of affairs. No. i took in eleven
bees within two hours, but her record was somewhat
confused, as two other females were going in and out at
the same time. We felt sure that neither of these was
hunting, but one of them shared in the labor of the nest
by helping with the work of excavation.

No. 2, however, was alone, so that we could keep a
definite account of her comings and goings. We watched
her from half past one until five, at which hour she
came home without a load, and at once closed the nest
for the night, after having stored thirteen bees in three
hours and nine minutes. In some cases the capture of

159

WASPS, SOCIAL AND SOLITARY

the bee occupied only one, two, or three minutes, while
at other times she was gone much longer. At each return
she stayed only an instant - - just long enough to de-
posit the bee - - inside the nest, and then spent a minute
in carefully closing the hole. The wasps that were going
in and out of nest No. i sometimes closed it when they
went away, but this was done in an untidy fashion, quite
different from the nicety and precision of No. 2.

At half after five o'clock the wasp that had been dig-
ging for some little time at nest No. i flew to nest No. 2,
opened it, and attempted to enter, but was quickly
driven out by the owner. She then dug a little in several
other places, finally returning to sleep in the family
home. On the next day we found that No. 2 was tolerat-
ing in her nest one of the females that had not yet begun
to hunt, but whether it was the one she had rejected the
night before or the fourth member of the sisterhood, we
could not tell. On the eighteenth, three days later, the
wasp had left this temporary home and made a nest for
herself four feet away on the hillside. The males were
still living in the first nest with two females.

When the weather was cold and cloudy punctatus
remained closely housed within the nest, or, at most,
came out to do an hour's digging, and then disappeared.
The warmer the weather, and the more brilliant the

1 60

THE BURROWERS

sunshine, the more rapidly they worked. When leaving
the nest they would often creep out and walk around
it three or four times before rising on their wings, and
even then would sometimes alight once or twice before
flying away. The males, especially, liked to stand about
for a time, watching their more industrious sisters at
their work. The females usually began the day with dig-
ging, and frequently closed it, toward night, in the same
way.

In order to see the method of stinging, we at one time
provided ourselves with a number of bees, and putting
one of them into a bottle, introduced a wasp. She seized
it almost immediately, with great vigor, and stung it
once, under the neck, and then dragged it up and down
the bottle by one antenna which was held in the man-
dibles. After a moment she shifted it and held it with
the second legs in the usual way. We now put in another
bee, which she also caught, stung in the same place, and
then dropped without relaxing her hold of the first one.
As she seemed to have nothing further to show us we
released her, and after circling a little she took into her
nest the bee that she was carrying.

In our next experiment we used a larger glass, thinking
that with more space we might see malaxation. The
instant that the wasp was introduced she grasped the

161

WASPS, SOCIAL AND SOLITARY

•

bee with one rapid powerful motion, and stung it just
under the neck as before. Then holding it with the
second legs she began to fly about in the glass. We now
introduced another bee, whereupon the first one was
relinquished, and the second was treated in exactly the
same way. The stinging was the beginning and the end
of the operation, and when we released her she at once
took the bee into the nest. There was no malaxation
outside, and certainly there was none within, as was
shown by the rapidity with which the wasps issued from
the nest after storing the bees. We were successful in
getting the wasps to sting only when we tried the experi-
ment with those that were hunting. When those that had
not yet begun to store their nests were put into the glass
they paid no attention to the bees.

The victim of the sting of punctatus is killed at once.
Life is extinct from the instant that the stroke is given.
This is true also of the honey-bee that is the victim of
Fabre's Philanthus apivorus; but the explanation that
he gives of the action of his wasp in thus dealing sudden
death instead of paralyzing its foe - - that the honey
must be sucked out of the bee before it can be safely used
as food for the larva - - does not hold good in our case,
since the honey that Halictus carries to mix with the
pollen upon which her offspring are fed, is not removed.

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As time went on we found on the island two other
Philanthus colonies, although that is rather too large a
word to apply to them, since one consisted of four nests
and the other of only two. When we came to excavate
the nests of this species we were greatly astonished at
the length of the gallery, and not until then did we prop-
erly appreciate the industry of these little wasps. It is
no small undertaking to follow one of their tunnels for

NEST OF PHILANTHUS PUNCTATUS

A-B, 3j inches; B-C, 5 inches; C-D, 14 inches;

D-E, 8 inches

twenty-two inches, even when, as in this case, the greater
part of it is parallel to the surface of the ground. We
did not find distinct pockets, as the soil was very crumbly
and fell in as we worked, but we came upon clumps of
bees an inch or so to one side of the gallery and about
three inches apart, with larvae in different stages of
development. In one nest we found twenty-six bees in

163

WASPS, SOCIAL AND SOLITARY

two clumps, some of them half- eaten, and some of them
fresh, but all quite dead. We have no doubt that punc-
tatus completely provisions one pocket and closes the
opening from it into the gallery, before she starts an-
other, making a series of six or eight independent cells.
The provision for one larva is probably twelve or four-
teen bees, the capture of which, in good weather, would
be a fair day's work.

That the males do not always stay on in their ancestral
home is shown by an observation that we made on the
only occasion that we ever saw this species in our garden.
Nothing was stirring at half past three o'clock in the
afternoon, and we had given up work and started for
home, when, in going up an inclined part of the field,
we noticed something in motion within a ragged-edged
hole which ran obliquely into the ground. It seemed
strange that a wasp should be beginning its nest at so
late an hour; but a wasp it was, as we could plainly see
when we took an attitude sufficiently humble. It was
loosening the earth with its mandibles, and then pushing
it backward with its hind legs and abdomen. We had
scarcely settled down to watching it when a second one
of the same species appeared, and with a good deal of
fuss and flutter began to dig its hole close by. The spot
chosen by this second one proved unsatisfactory, and

164

THE BURROWERS

another beginning was made in a new place. Again
something was wrong, nor was a third choice any better.
At last, however, the work was started in earnest, and
might have been carried to a conclusion if we had not
caught the little creature to satisfy a suspicion that had
been growing in our minds. Yes, we were right. The
worker was not a female making a nest for the rearing
of her young, but a male punctatus, preparing a shelter
for the night.

In the mean time the first wasp had pushed back such
a quantity of earth that the hole was entirely closed, but
every few minutes he came backing out to clear the way.
At the end of half an hour all became quiet. The door
remained closed, and doubtless the wasp was fast asleep.
Putting a blade of grass and then an inverted tumbler
over the nest, we left him for the night.

On removing the glass at half past seven the next
morning, we found the nest open but the wasp not visi-
ble. At half past eight the head appeared just inside the
hole, the long antennae twitching now to this side, now
to that, as if an inspection were being made. Soon the
head came out. The wasp stood for some minutes mak-
ing a survey, looking to right and left with lively jerks
of the body. Then, apparently concluding that the day
was not far enough advanced, he came out, whirled

165

WASPS, SOCIAL AND SOLITARY

around, and ran head-first into the nest. He probably
took another nap, for all was quiet until just before ten
o'clock, when the antennae appeared again. The survey
was taken as before, first from within and then with the
head in view. At last he flew out, and making three
circles, each one wider than the last, about the place,
flew away. He stayed out all day, and had not returned
at half past three in the afternoon ; but on going down
at half past four we found that he had gone in and closed
the door from below.

It is clear, then, that these males do not construct a
new lodging every night, but return to the same spot to
sleep. Other wasps creep into crevices. We have often
found them, in the morning, in the holes of the posts of
our cottage porch; but we are glad to be able to put it
down to the credit of one male that he has sufficient
foresight and industry to provide a sleeping-place, and
sufficient intelligence to return to the spot when the de-
clining sun warns him that evening is approaching.

While punctatus was in the height of its activity we
found another species, P. ventilabris, taking bees of
several genera and species into a ground nest. She also
carried her prey with her second pair of legs, and when-
ever she left her nest she closed the door. She was a
shy little thing, and did not approve of our interest in

166

THE BURROWERS

her. At one time, being startled by some movement on
our part, she dropped her load and flew away. We placed
the bee upon the closed nest, and when she came back
with another, she paused and looked at it, took in the
one she was carrying, and then returned for number
one. This was placed on the threshold while she entered
and turned around, and was then pulled in. Some wasps,
notably C. ornata and our little tornado, refuse to take
in their prey, even if they have caught it themselves,
excepting in a regular succession of events ; and thus the
more reasonable conduct of ventilabris gains in interest.
To the west of Milwaukee, across the valley of the
Menominee, rises a sandy hilltop which is a little insect
kingdom by itself. Ants of course abound, and the gentle
little solitary bees, with their loads of pollen, may be
seen everywhere, seeming to melt into the ground, so
quickly and quietly do they open their burrows. Here
Oxybelus plys her trade of fly-catching, and graceful
Ammophila dances with her shadow over the sunny
ground, while Cerceris rests in her doorway with an air
of leisurely superiority to the vulgar cares of life ; and
here, one day in early July, a sudden access of energy
seemed to strike Aphilanthops frigidus, a wasp which
we had found a year before taking in the wingless queens
of ants. All at once they were digging everywhere, biting

WASPS, SOCIAL AND SOLITARY

and scratching with great energy, and soon disappearing
in the depths of their sandy tunnels. So deep is their
primary gallery that even in this easy medium it takes
them the best part of a day to get it ready for storing ;
but once finished it doubtless serves as a home through
the season. It has at the entrance a little cup-shaped
vestibule where the wasp drops the ant as she enters,
running out of sight herself, and then, after she has
turned around, coming back to pull it within. This nest
is a very difficult one to excavate neatly, as the sand falls
at the slightest touch.

A day or two after we had seen frigidus making her
residential arrangements, we found twenty-five or thirty
within a few feet of each other, working with great ardor
at carrying in queens, the doors being left closed or open
according to individual judgment. The steadiest work-
ers brought one every forty minutes, scarcely pausing
inside the nest, but others made long stays within, leav-
ing the door closed. The ants were carried under the
body with all the legs folded around them, but they
were heavy things, and were often dropped as the wasp
flew across the field, giving opportunities for robbery
that were promptly taken advantage of. We picked up
one of these ants and placed it in the doonvay of a wasp
that had just gone in. She came up twice, looked at it,

168

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;

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ifesilS^^^H

THE BURROWERS

and backed down again; but the third time she first
touched it, then seized it and took it below. From an-
other wasp that was just entering we took the ant she had
dropped and moved it half an inch away. When she
had turned and come up for it, she seemed surprised,
came out and looked about, found it and dropped it in
the doorway, going in herself to turn around as before.
We seized this chance to move it again, and again she
came out, found it, took it back, and dropped it. This
was repeated five times, but when she took it in for the
sixth time, after dropping it, she whirled around and
picked it up so quickly that our malice was foiled.

We were puzzled by the actions of a wasp that ap-
proached her nest again and again, but always circled
away without entering, until looking closely we saw that
she was pursued by two tiny flies. When she alighted
and walked about awhile with her ant tucked under
the third leg on one side, the flies alighted also and
walked about behind her. In the end she evaded them
by a sudden drop into her hole.

A wasp now came circling along with an ant in her
grasp, and settled down between two small weeds that
grew about four inches apart. She stood quiet a mo-
ment and then began to dig, but had evidently struck
the wrong spot, for after a moment she moved and tried

171

WASPS, SOCIAL AND SOLITARY

another place. Not finding the entrance, she rose and
flew close under one of the plants and began to scratch
again, but still in vain. For ten minutes she persisted,
keeping within a few inches of the spot, and holding on
to the ant all the time, although it was dreadfully in her
way as she walked about. Then she dropped it and began
to dig more vigorously, dividing her attention between
the two spots she had attempted at first. She seemed
troubled at having to leave the ant, and often picked it
up and tried to hold it while she worked. Once in a
while she would take it with her, and after circling
about the spot would disappear, but in a few minutes
she would return. It seemed to us that two little plants
growing near together must have been her landmarks,
and that probably she had been deceived by the like-
ness that those before us bore to the ones near her nest.
Again and again she seemed to hesitate and think the
matter over, but gradually one of the holes absorbed
her more and more. At the end of an hour she was out
of sight in it, and had carried her ant down, although
she was still kicking out sand. It was evident that her
memory had played her false, and that she had either
covered her hole so neatly that she could not find the
spot herself, or had missed the place entirely. She had
accommodated herself to circumstances pretty well,

172

THE BURROWERS

although she ought to have realized earlier that it would
be easier to dig one nest than two.

We now tried to excavate a nest, but could not follow
the tunnel, although we found clumps of ants at differ-
ent levels, some with larvae feeding on them. The deep-
est were eighteen inches down. Hoping to secure a guide,
we borrowed an ant as it was dropped in the doorway
and tied a thread to it. The wasp pulled it in and took
it part way down with this attachment ; but before any
great depth was reached, the thread was seemingly
bitten off, as we found the free end without the ant.
A second attempt brought no better results.

So long as we were quiet the wasps did not notice us,
but after being disturbed they became shy and circled
about a good deal before entering. Some of the ants
were completely paralyzed, while others moved their
abdomens, legs, and mouth parts. All through the morn-
ing, the whole place was in a bustle, but when we came
back, after eating our luncheon in a shady spot, quiet
reigned ; the colony seemed asleep, and although we
waited for an hour not a wasp showed herself.

The ants that these wasps were bringing all had wings.
The European genus Fertonius takes worker ants which
can be picked up anywhere; but so far as we know,
these queens leave the nest only at the time of their

173

WASPS, SOCIAL AND SOLITARY

nuptial flight, after which the wings are lost. How then
are they captured ? Can it be that the wasps, though not
much larger than their prey, descend into the home of
the ants, bearding the lions in their den, and carrying
off their young queens by force of arms ? This smacks
of heroism.

Much interested in the matter, we carefully examined
the ant-hills of the neighborhood. Those on top of the
hill had openings too small to admit frigidus, supposing
she had wanted to enter, but down on the roadside below
we found some larger doorways and sat down beside
them. We had scarcely arrived when a frigidus appeared
on the scene, alighting six feet away. That she should
have come hunting so soon seemed almost too good to
be true, but she certainly was not doing anything else.
She did not dig, nor feed on the clover, nor circle about
as though looking for her nest, but began to clean and
brush herself assiduously. Then she climbed a tall grass
blade, and swinging at the top went through some curi-
ous gymnastic performances. Then she brushed herself
again, drawing her third legs over the sides of her abdo-
men. This went on from moment to moment, until half
an hour had passed, and more than once the painful
suspicion crossed our minds that this was some trifling
male putting in the hours between breakfast and

174

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luncheon. One encouraging fact cheered us : aimless
as the wasp appeared she was slowly drawing nearer
and nearer to the nest; and at last, alighting on the top
of a weed close by, she crouched there in a most peculiar
attitude, and gazed intently at the opening. Absorbed
and tense, she looked about to leap upon her prey ; but
after a time she relaxed and moved about a little. Pre-
sently she came close to the entrance and seemed on the
point of going in; but the ants were swarming up and
down, and we thought that perhaps that step required
more courage than she possessed. At any rate, she did
not enter, but hung about for some minutes and then
flew away.

Was this a young wasp out on her first hunt ? What
strange antiphonal desires must have stirred at the sight
of the nest, and how mysterious was the power that drew
her to it ! Was there in her brain any image of the queen
she must seek and sting and carry away from among
her guards and subjects? Or had she perhaps already
achieved the adventure, and did the memory of the
bitter nips that little ant jaws can give make it a harder
task than it was the first time, when she risked the ills she
knew not of ? That she hesitated and carried on the
work reluctantly seemed to show that her flesh was
weak and needed the prick of conscience to drive it on.

WASPS, SOCIAL AND SOLITARY

Had we here then the small beginnings of moral sense
and perception of duty ? Can it be that of such humble
origin is the power that "doth preserve the stars from
wrong"?

We went on with these meditations for several days
while lingering, with gradually diminishing hopefulness,
over one ant-hill after another. The wasps were carrying
in winged queens by the score, but they did not come
our way to find them; and although we ranged about
widely, we failed to see the capture. Occasionally we
met a frigidus hunting, running about on the ground
and poking her head, not only into ant holes, but into
holes of all sorts, and as we sometimes saw young queens
(wingless however) starting to dig their nests, we thought
these might be the object of the search. The weather
was cold and windy, most unpropitious for swarming,
and yet frigidus was working as briskly as ever; so that
we began to feel sure that she could not depend upon
meeting the queens outside the nest, but must enter to
get them. Just as this point we received a letter from
Mr. William M. Wheeler, well known as an authority on
ants, saying that he felt very sure that the wasp could
not extract the queens from the nest, but must find them
running on the ground, just after the nuptial flight,
before they dug their holes and started their colonies.

176

THE BURROWERS

Respecting this opinion, but still feeling unconvinced,
we caught a wasp in a glass, and carrying it to an ant-
hill, inverted it so that she was confined just over the
entrance. After buzzing up and down for a moment, she
alighted and walked calmly into the hole ; but a fraction
of a second later she came rushing madly out again,
pursued by the most furious lot of ants that ever de-
fended the home city against invasion. Down tumbled
our air castles about courage and duty, for however
frigidus gets her queens, it is not in that way. We have
not yet seen the meeting and the capture, but hope that
sometime we may be lucky enough to be on the right
spot at the right time.

Chapter VIII

THE WOOD-BORERS

OUR two species of Trypoxylon are both slender-
waisted black wasps, albopilosum having bunches
of snowy white hairs on the first legs, and measuring
three quarters of an inch in length, while rubrocinctum
is a little smaller, and, as the name implies, wears a red
girdle.

Although these wasps are called wood-borers, they
will use convenient cavities in any material. When we
went out to our summer cottage, in the last days of June,
1895, we found many little wasps of the species Trypo-
xylon rubrocinctum busily working about a brick smoke-
house on the place. Closer examination showed that in
the mortar between the bricks were many little openings
leading back for a considerable distance, which were
occupied by the wasps. It would seem that these holes
were excavated by some other agency than the wasps
themselves, as they were so much too deep for their pur-
poses that before using them they built a mud partition

178

THE WOOD-BORERS

across the opening about an inch from the outside of the
wall. Later we found nests of the same species in the
posts which support an upper balcony of the cottage;
and here, too, the wasps made use of holes which were
already excavated.

In the following summer we found large numbers of
these wasps at work in a straw-stack. The stack had
been cut off perfectly smooth on one side, so that many
thousands of the cut ends of the straws were exposed
to view, and these proved very attractive to rubrocinc-
tum. This species is very cosmopolitan in its tastes, for
we found it utilizing the small holes in the sticks of
a woodpile. The straws made the daintiest nesting-
places, however, and were well adapted to our purposes,
since they could be drawn out of the stack and split
lengthwise so that the contents could be easily studied.
The two halves could then be brought together again
without injuring the inhabitants, and thus we often
kept several sets under observation long enough to
watch the changes from the egg to the pupa. We found
Trypoxylon albopilosum nesting in holes made by beetles
in posts and trees, but never in straws. A third species,
bidentatum, was very common, nesting in the stems
of plants. During the month of August we saw many
individuals of this species hunting for spiders on the

179

WASPS, SOCIAL AND SOLITARY

blackberry bushes ; but at this time we were so much
absorbed in Crabro stirpicola that we never followed
them to their homes.

Rubrocinctum was more conveniently studied, and
through July and August we watched the comings
and goings of these little wasps. They were very good-
tempered, never resenting our close proximity nor our
interference with their housekeeping. By working hard
they could prepare a nest, store it with spiders, and seal
it up all in the same day. This we have seen them do in
several instances. In other cases the same operation
takes three or four days. In the second summer that we
worked with them we found one very energetic mother
that stored four nests in one day. It had rained hard
on the twenty-sixth of July, and no wasp works in such
weather. On the afternoon of the twenty- seventh we
took a straw just as the little mother was bringing in a
spider. We opened it and found that the innermost cell
contained eight Epeirids, with an egg on the abdomen
of the last one taken in ; the second cell was provisioned
with ten spiders, with the egg on the seventh, so that
three had been brought in after it was laid; the third
cell had the egg on the last spider, as did also the fourth.
All of these eggs hatched on the twenty-ninth, — the two
outer ones, that were laid last, between eight and nine

1 80

THE WOOD-BORERS

o'clock in the morning, and the two that were laid earlier
between two and three in the afternoon. This was the
biggest day's hunting that we have ever recorded for any
of our wasps.

With both species (T. rubrocinctum and T. albopilo-
sum), when the preliminary work of clearing the nest
and erecting the inner partition has been performed by
the female, the male takes up his station inside the cell,
facing outward, his little head just filling the opening.
Here he stands on guard for the greater part of the time
until the nest is provisioned and sealed up, occasionally
varying the monotony of his task by a short flight. As
a usual thing all the work is performed by the female,
who applies herself to her duties with greater or with
less industry according to her individual character ; but
the male doubtless discharges an important office in
protecting the nest from parasites. We have frequently
seen him drive away the brilliant green Chrysis fly,
which is always waiting about for a chance to enter an
unguarded nest. On these occasions the defense is car-
ried on with great vigor, the fly being pursued for some
distance into the air. There are usually two or three
unmated males flying about in the neighborhood of the
nests, poking their heads into unused holes, and occa-
sionally trying to enter one that is occupied, but never,

181

WASPS, SOCIAL AND SOLITARY

so far as we have seen, with any success, the male in
charge being always quite ready and able to take care
of his rights. The males, however, made no objection
when strange females entered the nest, as they sometimes
did by mistake, nor did the females object to the en-
trance of a strange male when the one belonging to the
nest happened to be away ; but in such cases the rightful
owner, on his return, quickly ejected the intruder. We
often amused ourselves, while we were watching the
nests, by approaching the little male, as he stood in his
doorway, with a blade of grass. He always attacked it
valiantly, and sometimes grasped it so tightly in his
mandibles that he could be drawn out of the nest with it.

When the female returns to the nest with a spider the
male flies out to make way for her, and then as she goes in
he alights on her back and enters with her. When she
comes out again she brings him with her, but he at once
reenters, and then, after a moment, comes out and backs
in, so that he faces outward as before.

In one instance, with rubrocinctum, where the work
of storing the nest had been delayed by rainy weather,
we saw the male assisting by taking the spiders from
the female as she brought them and packing them into
the nest, leaving her free to hunt for more. This was an
especially attentive little fellow, as he guarded the nest

182

THE WOOD-BORERS

almost continuously for four days, the female sometimes
being gone for hours at a time. On the last day he even
revisited the nest three or four times after it had been
sealed up.

It is upon the female that the heaviest part of the
work devolves. As soon as she has put the nest in order
she begins the arduous task of catching spiders where-
with to store it. It usually takes her from ten to twenty
minutes to find a spider and bring it home, but she is
sometimes absent for a much longer time. When the
spider has been carried to the nest the process of pack-
ing it in begins. This occupies some time, and appar-
ently a good deal of strength, - - the female pushing it
into place with her head, totally disregarding its com-
fort, all the spiders that are caught being pressed and
jammed together into a compact mass. While she is
busied in this way she makes a loud cheerful humming
noise. The number of spiders brought seems to depend
upon their size, in which quality they vary greatly, the
largest ones being six or eight times as large as the small-
est. Rubrocinctum fills her nest with from seven to four-
teen, while the larger albopilosum brings as many as
twenty-five or thirty. Those that we examined repre-
sented many different genera, and even different fami-
lies, although they were usually orb- weavers.

183

WASPS, SOCIAL AND SOLITARY

In a number of cases, during the first summer, after
several spiders had been stored, we gently drew them
out with a bent wire. In one nest in which there were
five spiders, we found, two hours after they had been
stored, that three were alive and two were dead. In an-
other, which the wasp had just begun to seal up, were
ten spiders. Three of these were injured in being drawn
out. Of the remainder four were alive and three dead.
On the anterior part of the dorsum of one of the living
spiders was the egg. It had probably been fertilized as
the female carried the male into the nest on her back.

When we discovered rubrocinctum in the straw-stack,
we made many observations as to the position of the
egg and the number and condition of the spiders. We
found that the egg was always placed either on the side
or the back of the anterior part of the abdomen. The
number of spiders stored was, as we have already stated,
from seven to fourteen. A fact that interested us greatly
was the remarkable accuracy shown by the wasp in
never selecting too large a spider for the calibre of the
straw. Oftentimes it was an extremely close fit, but it
could always be squeezed down. When they nested in
posts they used at times much larger prey. Unfortu-
nately we never saw this species capture its prey, nor
could we prevail upon it to sting in captivity, but the

184

THE WOOD-BORERS

number of spiders that we found in straws was so large
as to afford abundant evidence concerning the degree
of surgical skill possessed by the wasps. P. marginatus
and P. scelestus, in overpowering their large fierce
Lycosids, must sting when and where they can, but
most of the spiders taken by rubrocinctum are inoffen-
sive creatures, and there is so little need to be careful

TRYPOXYLON RUBROCINCTUM

or adroit in dealing with them that she has time and
opportunity to sting the exact spot that will give the
best results.

The concentration of the nervous system in the Arach-
nida would seem to conduce very strongly to uniform re-
sults from the stinging of the wasps. Unlike the larva

185

WASPS, SOCIAL AND SOLITARY

used by Ammophila, with its chain of ganglia, in the
Araneidae the whole central nervous system, including
the brain and the ventral cord, forms a single mass,
pierced by the oesophagus. The greater part of this mass,
which lies behind the oesophagus, represents the fused
ventral cord from which the nerves radiate. It is evident
that a thrust given in almost any part of the ventral face
of the cephalothorax, or even on either side of the an-
terior half of its edges, would reach the nervous centre.
With these facts before us let us turn to the notes made
upon the condition of the spiders that had been stung
and stored up in the nests of the straw-stack. By the
"first cell" we mean the last one stored, which was
naturally the first one opened.

July ii. Opened a nest of rubrocinctum. The first cell
contained fourteen live spiders with a newly laid egg.
Some of the spiders were very lively, moving spontaneously.
Second cell, ten spiders, one dead, others alive, and an
egg. Third cell, eight spiders, three dead and five alive,
and the egg.

July 12. In each of the first and second cells one spider
has died since yesterday, while in the third there is no
change in their condition. The egg in the third cell hatched
at nine in the morning, and the one in the second cell at
three in the afternoon.

July 13. In the first cell all the spiders are dead but one,

1 86

THE WOOD-BORERS

and in the second, all but four, while in the third none are
alive.

July 15. All the spiders in the second cell are dead.

July 1 6. The one spider in the first cell has outlived all
the others, but that, too, died to-day.

The record of another set of nests is as follows: On
July eighth we took a straw with a wasp as she went
in with her spider. The cell was not sealed up. It
contained fourteen specimens of three species of orb-
weavers, and the egg was apparently just laid. The
spiders were pushed in very tightly, and the legs and
abdomens were, in many cases, bent to one side. All
were limp, but alive. By July tenth, four were dead ;
on July eleventh the egg hatched. By July thirteenth
all of the spiders were dead.

It is unnecessary to give the history of other nests in
detail, since these facts make it clear that there is a great
variation in the degree of severity with which the spiders
are stung, so that while with some the paralysis is com-
plete, with others it is only partial. Some were killed
outright, others lived two or three days, while still others
survived for two weeks. Compared with the work of
the Pelopaei it would seem that a smaller number of the
spiders are killed at once, while a larger number die
after the lapse of a few days. None of the victims of

187

WASPS, SOCIAL AND SOLITARY

Trypoxylon live so long as the most perfectly paralyzed
spiders of the mud-daubers. Two of them lived ten and
fifteen days respectively, while with Pelopaeus one sur-
vived until the thirty-eighth and one until the fortieth
day.

The egg requires from forty to sixty hours for its de-
velopment, and the larva feeds for seven or eight days
before spinning its cocoon. Those that we watched
usually disposed first of the abdomen and then of the
cephalo thorax ; sometimes they would consume several
abdomens before attacking the other parts. After the
body was devoured the legs were picked up and eaten.
When the supply of food was generous, portions of the
spiders were sometimes left untouched. The cocoons
resembled in general appearance and structure those
of Pelopaeus.

When a female returns with her load she usually
hunts about for a few moments before finding her nest,
sometimes entering, first, two or three that are empty
or are occupied by other wasps ; but we do not wish to
cast any reflection upon the sense of locality of a crea-
ture that is able to find one particular straw out of the
many thousands in an expanse of stack twenty feet
high by twelve wide. We ourselves can testify, from
experience, to the extreme difficulty of the task.

188

THE WOOD-BORERS

After the storing process is completed the female
seals up the nest with mud. In the case of one rubro-
cinctum that we were watching, she began to close the
opening at four in the afternoon and finished her work
just thirty minutes later. In this time she made ten
journeys for mud, bringing it in pellets in her mandibles.
In another case, also a rubrocinctum, the female, after
bringing so many spiders that the cell was full up to the
very door (which we saw in no other case), went away
without closing it, and never returned. The male seemed
uneasy at her conduct, and several times flew away,
staying an hour or two and then returning ; but after a
time he too deserted the nest. Whether some evil fate
overtook the female or whether there was some failure
of instinct on her part, can only be conjectured; but the
latter hypothesis is not untenable, since out of seventy-
six nests that we had under observation seven were
cleaned out and prepared and were then sealed up
empty. We have often found similar cases among the
nests of the blue mud-dauber wasps, where it is not a
very uncommon thing for the absent-minded females to
build their pretty little cylindrical nests with infinite
care and patience, and then to seal them up without put-
ting anything inside.

Cocoons of rubrocinctum that were gathered in the

189

WASPS, SOCIAL AND SOLITARY

month of August remained over the winter and hatched
in May and June.

Almost as interesting as rubrocinctum is the slightly
larger species, T. albopilosum. This wasp has a great
liking for the posts that support the balcony of our cot-
tage, a preference that is very convenient for us, as it
enables us to sit in the shade and watch their doings at
our ease.

One afternoon as we sat, literally, at our posts, a fe-
male of albopilosum came humming along, looking very
important and energetic, as though she had planned
beforehand exactly what to do. She entered an empty
hole, head first, and at once began to gnaw at the wood,
kicking it out backwards with considerable violence.
After a few minutes she changed her method of work,
and began to carry out loads of wood dust in her mandi-
bles, dropping it in little showers just outside the nest,
and then hastening back. In forty minutes she carried
out, in this way, upwards of fifty loads. She then flew
awav, but returned in ten minutes with a male. She

* *

alighted, he took his place on her back, and they went in
together.

After a time they came out and both flew away, but the
next morning they came back and the nest was stored.

In this species the male does not always come out of

190

C .. ., . M . - -- . ,

L-" - ,v-i, ,),,',-"";•' <? . /-''''«/•' , .," .. .-,, -^. ^ ;,(>- »»:*- ;., /;.

MALE TRYPOXVLON AWAITING THE FEMALE

THE WOOD-BORERS

the nest when the female brings a spider, the nest being
enough larger than in rubrocinctum to accommodate
them both comfortably. As a usual thing, however, he
enters on the back of the female. The spiders brought
by albopilosum are larger than those used by rubrocinc-
tum. They sometimes bring such heavy specimens of
Epeira insularis that they are carried with difficulty,
the wasp alighting and dragging the spider into the
hole instead of flying directly in as usual.

We watched a number of albopilosum nests during
the second summer, finding them in several instances
through the loud humming of the female while she was
pushing the spiders into her hole. From our not very
extensive study of the spiders taken by this species we
are of the opinion that some are killed at the moment
of capture, while others that are only paralyzed die in
the nest from day to day.

Mr. W. H. Ashmead has noted that albopilosum
stores its nest with aphides, but in the cases that we
observed they used only spiders. There can be no mis-
take on this point, as we more than once took the spider
from the wasp as she was entering the nest. In a recent
letter Mr. Ashmead says that his notes were made in the
field, and that he probably mistook some closely allied
species for this one.

193

WASPS, SOCIAL AND SOLITARY

We are not as familiar with the habits of T. bidenta-
tum as with those of the other two, but we have a few
notes relating to the female. This little worker is the
smallest of the three, and like her sisters is a confirmed
spider-hunter. Once, when out among the raspberry
bushes, we had the good fortune to witness a capture.
The wasp seized the spider, as it rested on a leaf, by the
top of the cephalothorax, and, holding it firmly, curved
her abdomen under and stabbed the ventral face of the
cephalothorax. All her motions were deliberate, and
after the operation she delayed a moment before picking
it up by a leg and flying off. We often found raspberry
stems which had been filled with spiders by this wasp,
but we do not know the length of time required for the
development of the egg, nor how long the larva eats be-
fore pupation. The cocoon is very different in appear-
ance from those of rubrocinctum and albopilosum, be-
ing exceedingly long, slender, and almost white, instead
of short, wide, and brown. The perfect insects come
out in September, and the last cocoon formed is the first
one to hatch. This was also true of the cocoons of
rubrocinctum formed in straws.

Years ago, when we found that many of the orb-
weavers laid enormous numbers of eggs (A. cophinaria
from 500 to 2000), we wondered what became of the

194

THE WOOD-BORERS

thousands of spiderlings. An acquaintance with Trypo-
xylon has shown us their fate, and has given us an illus-
tration of how closely the two groups are related. To
make a very modest estimate there must have been twenty
wasps at work in our straw-stack. During the six weeks
which make the busiest part of their working season
each of these must have stored, at the very least, thirty
cells, putting an average of ten spiders into a cell. It may
then be considered certain that the straw-stack, with its
working surface of twelve by twenty feet, was the mauso-
leum of six thousand spiders, and it is very probable that
twice as many were interred within its depths. It must
be remembered, too, that before the spiders have grown
large enough to be interesting to rubrocinctum, biden-
tatum has had her turn at them, and that those that are
allowed to grow too large for rubrocinctum are preyed
upon grade after grade, first by albopilosum and finally
by Pelopaeus, Pompilus, and other genera.

The wasps of this genus lose their interest in family
affairs about the second week in August, though after
this time they may still be seen taking their well-earned
holiday on the blossoms of the aster and the golden-rod.

Chapter IX

THE SPIDER-HUNTERS

WHILE Ammophila provides caterpillars for her
larva, and Bembex, after the manner of the
social wasps, feeds her young from day to day on dead
flies, the Pompilidae, so far as their habits are known,
all prey upon spiders. The family is a large one in the
United States, one hundred and twenty-seven species
having been described. The members of the group differ
in size, color, and habits, and the individuals of the same
species show the very considerable amount of variation
which seems common to all those groups of animals
which have been carefully studied. Happily the old
notion that habits and instincts, unlike structural pe-
culiarities, are always uniform, is no longer insisted
upon, and there is ample evidence for the opinion that
functional variations are as common as morphological.
We have studied five species of this family, and have
found their respective roles of great interest.
According to Fabre, the French members of this

196

THE SPIDER-HUNTERS

genus, although they do not make their own nests, still
exercise some foresight in the matter by selecting a
suitable crevice before catching their prey. Among the
species that we have studied, quinquenotatus, biguttatus,

TORNADO WASP (POMPILUS QUINQUENOTATUS) DIGGING NEST

fuscipennis, marginatus, and interruptus first catch the
spider and then make the nest; while calipterus and
scelestus prepare the nest before capturing their prey.
Quinquenotatus is usually rather less than half an
inch in length and is black, the abdomen having a
variable number of white bands and a white tip.

197

WASPS, SOLITARY AND SOCIAL

It was on the last day of July that, as we were walking
through the bean field, we saw a cloud of fine dust which
came spurting up out of the ground like water in a foun-
tain. By watching intently we saw that the cause of the
commotion was the rapid action of the legs of some
little creature that was almost hidden in the earth, and
this proved to be our first example of P. quinqueno-
tatus.

She was working away as furiously as though she had
studied the poets and knew her carpe diem by heart.
Faster and faster went the slender little legs; higher
and higher rose the jet of dust above her. Then sud-
denly there was a pause. The burrower had met with
some obstacle. A moment more and she came backing
out of the hole, her feet slipping on its crumbling edges.
In her mandibles she carried a pebble, which was taken
to a distance of four or five inches. Then, moving
quickly, she swept away the dust that had accumulated
near the mouth of the nest, reentered the hole, and re-
sumed the labor of excavation.

We thought that the rate at which she worked was
too violent to be kept up very long; and sure enough,
before ten minutes had passed the nest was deep enough
for her purposes, and we afterward learned, to our cha-
grin, that it was too deep for ours. The wasp came out,

THE SPIDER-HUNTERS

circled round the spot three or four times, and then flew
off like a hurricane. Never have we seen a creature so
fiery, tempestuous, cyclonic. Before we knew her proper
title we took to calling her
the tornado wasp, and by
that name we shall always
think of her.

Her flight was too rapid
to follow, but in a minute
we saw her returning. She
was carrying a spider, a
good - sized specimen of

, . , POMPILUS QUINQUENOTATUS

Epeira stnx, which she had

evidently deposited somewhere in the neighborhood
before beginning to dig. Alighting near by, she left the
spider lying on the ground, while she ran to her nest and
kicked out a little more earth. Then seizing it by one
leg, she dragged it, going backward herself, into the
nest. She remained hidden for about two minutes,
then reappeared, and, seeming to be in as great a
hurry as ever, filled the hole with dirt. To disguise
the spot and render it indistinguishable from the rest
of the field was her next care. Hither and thither she
rushed, now bringing little pellets of earth and placing
them above the nest, now sweeping away the loose dust

199

WASPS, SOCIAL AND SOLITARY

which might suggest the presence of the cache, and
now tugging frantically at a stone which she wanted to
place over the hidden treasure, but which was too deeply
embedded in the earth to yield to her efforts. She did
her work faithfully, although with such eager haste that
all was completed at the end of twenty minutes from
the time we saw her first. So well was the place hidden
that it was only by careful orientation that we could be
certain of its exact locality.

Her task accomplished, away flew our little tornado
as though she were pursued by the avenging spirits of
all the spiders that she had murdered, although more
probably she was off in quest of another of those meek
and helpless victims.

"Now," we said, "we will trace out the nest and
make a drawing of it. We will take the spider home and
note its condition from day to day, watching at the
same time the development of the larva."

Enjoying this little air-castle, we began to excavate.
Having had experience with the nests of Ammophila
and Diodontus, and knowing that the task might not
be so easy as it looked, we went to work with all possible
care. It seemed, however, that some magician's trick
— some deception of the senses - - had been played
upon us. We saw the spider interred ; we at once dug

200

THE SPIDER-HUNTERS

up the place and found nothing. Slowly and carefully
we enlarged our circle. We went down deeper until
the opening was large enough to hold a thousand spiders,

- still nothing. Then we tried another plan. Gathering
all the earth that we had taken out, we sifted it through
our hands - - in vain. At last we acknowledged our-
selves beaten, and trudged home empty-handed.

Our pride was destined to be still further humbled.
Three times within that same week we saw the tornado
wasp bury her spider, and three times we failed, just as
incredibly, to find it. On the last of these occasions we
did not let her fill the nest, attempting to follow the
tunnel and get out the spider as soon as the egg was
laid, but the loose, unstable character of the soil de-
feated us.

Our fifth example, however, dug her nest, not among
the beans but lower down in the potato field, where the
ground was firmer ; and here we made our first success-
ful excavation, - - successful only up to a certain point,
since in getting out the spider we dislodged the egg,
and although it was at once replaced it never developed.
The spider was placed three inches below the surface,
but we could not trace the tunnel. At our next oppor-
tunity, wishing to make good this failure, we placed a
blade of grass in the opening just after the wasp began

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to fill it. On being disturbed she assumed the most
comically threatening aspect, whirling around, lifting her
wings, and then circling about us. As soon as we moved
back she dashed at the grass-blade and pulled it out
with great energy. A few minutes later we made a similar
attempt, and again she frustrated our plan ; but when we
inserted the grass-blade for the third time, the nest being
now half filled, she let it remain. Some hours later,
with this to guide us, we succeeded in tracing the nest,
but much to our disappointment found it transformed
into a banqueting hall. Scores of tiny red ants had dis-
covered this rich store of food. They had eaten the egg
and were rapidly finishing the spider.

Twice afterward, in opening these nests, we found
the same ants in possession before us. It is probable
that they are a formidable enemy to this and other
species of Pompilus ; but they seem to find the spider
by burrowing beneath the surface, so that the elaborate
hiding of the nest from above cannot be meant as a pro-
tection from them.

Pompilus quinquenotatus has a decided preference as
to the spider that she takes. While Pelopaeus and Try-
poxylon are entirely indifferent both as to size and
species, and the more nearly related Pompilus margi-
natus takes Thomisus, Drassus, Attus, Agalena or

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THE SPIDER-HUNTERS

Lycosa, this more fastidious wasp will not be tempted
from the spider of her choice. In more than fifty ex-
amples the victim in the play was invariably Epeira
strix. If she must confine herself to one species she has
made a fortunate selection, since there is no other spider
so common in our neighborhood, not only in the woods,

EXAMPLE OF EPEIRA STRIX THAT HAS BEEN
PARALYZED AND HUNG UP ON BEAN PLANT
BY POMPILUS QUINQUENOTATUS, THAT IT
MAY BE OUT OF THE WAY OF ANTS WHILE
SHE DIGS HER NEST

but around the barns and outbuildings. Most frequently
it was the female that was taken, but this does not im-
ply a preference for that sex, since the females are more

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WASPS, SOCIAL AND SOLITARY

abundant than the males. We have never seen the
spider captured and do not know where the sting is
given, but certainly this wasp wounds her prey very
severely. The spiders that we took from her were either
dead, or so completely paralyzed that it required great
care and the use of a magnifying glass to determine
that they were alive.

The next stage of her proceedings we are familiar
with, as we have frequently seen the wasp carry the
spider. Unlike her sister, marginatus, she usually flies
with it, and seems not at all encumbered by its weight.
In many cases, however, she drags it, holding it by one
leg and running rapidly backward.

A suitable place for the nest being found, the spider
is very prettily taken care of while the work is in pro-
gress. A plant, usually a bean or a sorrel, is chosen, and
the strix is hung in the crotch of a branching stem, where
it will be safe from the depredations of ants. This pre-
caution is not always taken. We have many times seen
the spider left on the ground, although there were plenty
of plants at hand.

The next point is to decide upon the precise spot
for the nest, and here our wasp shows herself very un-
certain and hard to please. Never have we seen one
settle down and complete her work in the spot first

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THE SPIDER-HUNTERS

chosen. She dashes at a place and scratches and digs
away with furious energy for a few minutes, and then,
starting up, she darts wildly hither and thither until a
new place, near by, is fixed upon and another beginning
made. In one instance eight nests were started and
some of them nearly finished, the little worker seeming
to be beside herself with excitement. After the decision
is finally made the tunneling is a rapid process. In one
case it took the wasp a whole hour to complete the work,
but out of the thirty nests that we saw made, nineteen
were finished in from twenty to twenty-five minutes.
Like Fabre's Sphex the wasp interrupts herself three
or four times to visit her spider and make sure that it is
safe. When all is done she brings the strix to within
a foot or two of the opening, runs to the nest to take a
final look, and then, going backward herself, pulls it
inside.

In two instances we saw the fidgety little creature
go through a most comical performance, which again
recalls the Sphex of Fabre. Leaving her treasure on
the ground, she ran to the nest and kicked out a little
more earth; hastening back she dragged it an inch
nearer ; then away she went to the nest again for more
digging, and so on, dropping her spider half a dozen
times before she at last brought it home. In two other

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WASPS, SOCIAL AND SOLITARY

cases in which there was no such anxiety about the
size of the nest, there was, in reality, more reason for it.
Indeed, in one instance the opening had to be enlarged
before the spider could be taken in. There is a wide-
winged parasitic fly that, having nothing else to do, lays
prodigious numbers of eggs, not in any particular nest,
but at the edge of holes wherever it may chance to see
them. It hovers about over the ground until it comes
to an opening, dips down twice or thrice, ovipositing
each time, and then passes along. The habit of scratch-
ing out a little dirt at the threshold, just before the prey
is brought in, seemingly from a desire to enlarge the
nest, or in other cases from mere nervousness, is per-
haps of use in destroying these eggs, which might other-
wise adhere to the spider or caterpillar as it is dragged
over them.

The laying of the egg takes only two or three minutes,
and then the hole is filled up. In this part of her work
quinquenotatus shows a great deal of variation, some-
times coming out of the hole and sweeping in the dirt
with her first legs and sometimes standing in the tunnel
while she draws the earth in with her mandibles and
then jams it down with the end of her abdomen. The
former plan was in vogue in the garden, while the latter
was more common with the wasps on the island. After

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THE SPIDER-HUNTERS

the hole is filled the spot is covered with pellets of earth
and pebbles brought from a little distance, very much
as is done by Ammophila.

When we found that quinquenotatus was a very com-
mon species, and that nearly every day brought us a
fresh example, we thought that we had the question
of its stinging habits in our own hands. What could
be easier than to carry a strix about with us and to ex-
change it, when opportunity offered, for the paralyzed
spider of the wasp? The good results obtained by
Fabre and Marchal from this manoeuvre made us con-
fident of success. We did not doubt that when the wasp
came for her spider and found it livelier than it ought
to be, she would repeat the stinging operation before
our eyes.

Accordingly, the next time that we saw quinquenota-
tus digging we made a diligent search for her spider,
and soon found it on a bean plant five feet away. Just
as we discovered it, however, the wasp swooped down
and carried it to some purslain, close to the hole, where
she hung it up again, while she went to make her final
preparations at the nest. We seized our chance, and
quickly substituted a fresh strix for the one that had
been paralyzed. According to the habit of its species
when danger threatens, it kept perfectly quiet, and when

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WASPS, SOCIAL AND SOLITARY

the wasp returned it was hanging there as motionless
as a piece of dead matter. How she knew the difference
was a mystery, but she would not touch it. She seemed
to think that she had made a mistake in the locality
and that her own spider must be hanging somewhere
close by, for she hunted all over that plant and then
over several others near to it, returning continually to
look again in the right spot. After five minutes she gave
it up, circled about three or four times, and flew off in
the direction of the woods to catch another spider.

Why did she go to the woods? When she realized
that the strix she had stung was gone and that she must
have another, why did she not take the one that hung
there in plain view? Our failure could not have been
due to the fact that we had handled the spider, since,
when on other occasions we took one that had been
paralyzed, examined it and then returned it to the wasp,
she accepted it without hesitation.

Disappointed though we were at the irrational con-
duct of our wasp, we resolved to await her return and
to try again. In forty minutes she came back with an-
other spider, but instead of taking it into the nest she
hung it upon a bean plant near by and then proceeded
to dig a new hole a few inches distant from the first.
Foolish little wasp, what a waste of labor ! Truly, if

208

THE SPIDER-HUNTERS

you are endowed with energy beyond your fellows you
are but meagrely furnished with reason.

Again we availed ourselves of our opportunity, and
substituted our spider for hers. This time it had grown
weary of playing its motionless role, and frequent read-
justments were necessary in order to keep it in position.
At the moment that the wasp came back to take it, the
spider scrambled from its place and began to make its
way along the stem. The wasp evidently saw it, for she
hovered over it a moment. She then flew to the next
plant, where she hunted about over the leaves and
branches in search of her lost treasure. After a time
she returned. The spider had now come to a standstill,
and the wasp examined it attentively, although without
touching it. She then flew away without circling at all,
which might, perhaps, be taken as an indication that
she had no intention of returning to a place where she
had fared so badly.

Just at this moment we chanced to see another para-
lyzed strix hanging near by. Again the exchange of
our specimen was accomplished; but when the second
wasp came to find her spider she gave us no more satis-
faction than the first. The substitute hung there quietly
enough. We ourselves could not have distinguished it
from the original, but quinquenotatus took a good look

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WASPS, SOCIAL AND SOLITARY

at it, decided that something was wrong, hunted about
a little for her own spider, and then flew away.

We had then, as the fruit of our morning's work,
gained nothing in regard to a knowledge of the stinging
habits of our wasp, but at least we had secured three
freshly paralyzed spiders to add to our laboratory col-
lection. As to the strix that had so kindly assisted us
in our experiments, we placed it on a bush in the plea-
santest and most secluded corner of the garden and left
it there, wishing it a long and happy life.

Later on in the season we tried the same experiment.
Taking her spider from quinquenotatus as she was
dragging it to her nest, we offered her a very lively strix
in its place. She would not notice it at all, and soon flew
away. Half an hour later she reappeared, and seemed
to be looking for a place to dig. As she ran about on
the ground we offered her another spider, dropping it
on the ground in front of her. This one behaved ad-
mirably, drawing up its legs and keeping perfectly still,
not moving even wrhen she felt of it and turned it over,
but it was left without any display of interest or emotion.

One day we saw a quinquenotatus finish her nest and
go after her spider. She was absent for some time, and
when an ant passed by, dragging a paralyzed strix that
had evidently been stolen from some wasp, we thought

210

THE SPIDER-HUNTERS

that the one we were watching had been robbed, and
rescuing the spider, placed it in the doorway of the
nest. We had judged wrongly, for a moment later our
wasp came back bringing her own spider, and dropping
it near by, ran to look at her nest. She was disturbed
at finding the way blocked, and dug out a little earth
to one side of the strix. Then she flew to some holes in
the ground not far away and dug a little, first in one and
then in the other. After this she took a look at her spider,
and then went back and dug a little more at her own
nest. Finally she seized the impeding strix by a leg,
dragged it out of the way and paid no further attention
to it, storing her own spider and departing, although
the one she had rejected might have saved a hunting
expedition.

At another time we saw two wasps digging their nests
two or three feet apart. One of them finished before the
other, and being unable to find her own spider (probably
it had been carried away by the ants), she seized that
of her neighbor and bore it away. The rightful owner
saw from a distance what was happening, and ran to
the rescue. A violent scrimmage ensued, the two wasps
clinching and rolling over and over together. The rob-
ber escaped and made off, but was followed and caught
again. She fought so well for her ill-gotten treasure,

211 •

WASPS, SOCIAL AND SOLITARY

however, that she finally conquered the other and hur-
ried off with her prize. She showed by her manner that
she felt the need of haste, for instead of laying the spider
down and looking at the nest, she dragged it directly in,
as though she feared another attack. This was the first
time that we had ever seen these wasps fighting over
their prey, and we were surprised to find that they would
take spiders which they had not captured themselves,
since when we had tried to exchange with them they had
refused to carry out our scheme. This was clearly an
intelligent act, and could not be an affair of instinct.

Once again we witnessed a similar struggle. One of
these wasps was laboriously dragging her strix up a
steep hillside, when a much bigger one of the same spe-
cies descended upon her and seized the spider. She was
loath to give it up, and they both pulled until it seemed
as though the poor creature would be dismembered.
The highway robber came off victorious, and after flying
to a distance hung the spider up while she finished a
partly made nest, and then stored it away. It may be
said in extenuation of her conduct that since she had a
nest started she had probably been robbed herself, and
therefore felt that she was entitled to a spider.

The nests of quinquenotatus vary considerably ac-
cording to the kind of soil in which they are made, the

212

THE SPIDER-HUNTERS

firm clay of the garden giving a result quite different
from the fine dry earth of the island, in which they are
usually much larger, and scarcely to be distinguished
from the holes of Bembex spinolae. In both localities,

NEST OF P. QUINQUENOTATUS

however, the nest consisted of a short tunnel, running
obliquely downward, with a slight enlargement at the
end, but with no change in the direction of the gallery.
In the loose sand of a steep hillside we found that the
wasps had a different method. Their tunnels in this
place filled up nearly as fast as they could dig them,
and when they had reached a depth of half an inch they

213

WASPS, SOCIAL AND SOLITARY

turned off at a right angle, and excavated in an entirely
new direction. They probably derived some advantage
from this variation, for we saw four in succession follow
the same plan, which certainly appeared to be an in-
telligent adaptation of means to ends.

We once saw a wasp of this species digging her nest
on the Bembex field. When finished it was a large hole
which could not have been distinguished from those
of spinolae, which were open all about, the weather
being bright and sunny. She flew off, and soon reap-
peared with her spider, which was dropped three feet
away while she ran to make sure that all was right;
and now followed something that we had never seen
before - - she could not find her nest. She flew, she ran,
she scurried here and there, but she had utterly lost track
of it. She approached it several times, but there are
no landmarks on the Bembex field. We have often
wondered how they find their own places. After five
minutes our wasp flew back to look at her spider, and
then returned to her search. She now began to run into
the Bembex holes, but soon came out again, even when
not chased out by the proprietor. Suddenly it seemed
to strike her that this was going to be a prolonged affair,
and that her treasure was exposed to danger ; and hurry-
ing back she dragged it into the grass at the edge of the

214

THE SPIDER-HUNTERS

field, where it was hidden. Again she resumed the hunt,
flying wildly now all over the field, running into wrong
holes and even kicking out earth as though she thought
of appropriating them, but soon passing on. Once
more she became anxious about the spider, and carry-
ing it up on to a plant suspended it there. Now she
seemed determined to take possession of every hole
that she went into, digging quite persistently in each,
but then giving it up. On one that seemed to be un-
occupied she labored at enlarging the entrance, until we
thought that she had mistaken it for her own, or at
least had determined to use it. At last, however, she
made up her mind that all further search was hopeless
and that she must start afresh ; and forty minutes from
the time that we saw her first she began a new nest close
to the spider, as though she would run no more risks.
This nest was successfully completed, and the spider
was stored away without further misadventure.

The egg of quinquenotatus can be but lightly attached
to the spider, for only once, out of many attempts, did we
succeed in getting it out without displacing it. In this
case three days elapsed before it hatched. The larva ate
for a day or two, but then pined away and died. An-
other nest was opened on the tenth day after the egg
was laid, and in this the spider had been entirely eaten

215

WASPS, SOCIAL AND SOLITARY

and the larva was just spinning its cocoon; so that the
larval stage probably occupies about a week.

A summary of our notes shows a very wide variation
in the condition of the spiders stored by this wasp. Out
of eleven that were stung three were killed at once, two
lived four days, one five, one eleven, one twenty-three,
one twenty-five, one thirty-one, and one at least forty
days and probably longer.

We look back with much pleasure upon our acquaint-
ance with this gay, excitable little wasp. She was so full
of breezy energy that it was always delightful to meet
her, and she showed so wide a variation in individual
character that we seldom watched her without learning
something new.

Pompilus fuscipennis, a little smaller than P. quinque-
notatus, is black, with the red girdle that appears so
frequently among the solitary wasps. The first time
that we ever saw this wasp she was running rapidly
backward over the bare ground, the brilliant red of her
body flashing in the sunlight as she dragged along a little
spider of the genus Thomisus. Presently she carried it
up on to a leaf and began to bite at it, but being dis-
turbed by an ant, hurried on with a much agitated man-
ner. Soon she stopped again and resumed her attack,
biting savagely at the legs near their junction with the

216

THE SPIDER-HUNTERS

body, and now, looking closely, we saw that two of them
had been completely cut off. While occupied in this way
the wasp was evidently intensely excited. She lay on
one side with the abdomen bent under, turning the
spider over and over as she worked. After a time she
carried it onward to the potato-field, where the plants
afforded some shelter, and placing it upon a leaf, well
above the ground, began to dig near by. She worked
almost entirely with her mandibles, lying sometimes on
her side and sometimes on her back as she cut away
the earth, which was pushed out with the end of her
abdomen. When she had worked for ten minutes and
had gone in the length of her body, she picked up the
spider and rapidly made off with it, several times rising
on her wings and flying backward for a few inches. A
little further along she again deposited it on a leaf and
began to dig in a fresh place. At the end of twenty min-
utes the nest was ready, but in bringing the spider she
missed her direction and carried it to one side. Drop-
ping it on the ground, she began to hunt about for her
hole, but was distracted with excitement and ran so
far afield that we feared she would never find it. At
last, however, she came to the place, ran in for a mo-
ment, brought the spider nearer, dropped it and ran
to the nest once more, caught it up again, and tried to

217

WASPS, SOCIAL AND SOLITARY

back in with it. She was holding it by the under side
of the body, the venter being toward the hole, and the
legs spread out and stopped its entrance. A moment's
tugging convinced her that this would not do, and she
then turned the spider over, holding it by the back,
whereupon the legs at once folded themselves across
the underside of the thorax, and it was drawn out of
sight.

After the egg was laid the wasp came up to the edge
of the hole, and drawing in some earth with her mandi-
bles began to dance up and down upon it, jamming it
into place with her abdomen. Afterwards she came
up higher and drew the dirt in with her first legs, not
getting out of the hole until it was entirely filled up.
Then began a remarkable performance. Bracing herself
firmly on her legs she used the end of her abdomen as
an instrument, and with it she now pounded the earth,
now rubbed it, like a pestle in a mortar, and now used
it as a brush to sweep away loose dust. Sometimes she
would throw a little earth back under her body with her
mandibles and rub it down with her abdomen. This
part of the work being finished, she spent a few minutes
in sweeping the ground with her first legs, and then
brought a quantity of small objects and placed them
over the nest, - - a little stick, the petal of a faded flower,

218

THE SPIDER-HUNTERS

a scrap of dead leaf, and so on, until ten or twelve things
had been collected. This artistic finishing up of her
duties recalled Ammophila ; but among our subsequent
examples of fuscipennis we never saw one do her work
with such nicety. They were usually contented to fill
in the nest more or less compactly, sometimes doing
much of the work from the outside, to brush off the
surface without any rubbing or pounding, and then to
bring two or three little pebbles or lumps of earth
to place over the spot.

So far as we were concerned this was one of the most
fearless of the wasps, not even interrupting her work
when we once placed a glass over her as she was filling
her nest; but the approach of an ant would throw her
into a perfect panic, and seizing her spider she would
make off with every sign of terror. It is difficult to under-
stand why wasps of this species, as well as of biguttatus,
never offer combat to the ants that rob them right and
left, but invariably seek safety in retreat. Their attitude
toward other robbers is quite different. We once saw a
fuscipennis that was dragging a Lycosid attacked by a
bigger wasp of the same species. Number One left her
spider on the ground and chased Number Two to a dis-
tance; but no sooner had she returned and taken it up
than Number Two, bold and unashamed, was at her

219

WASPS, SOCIAL AND SOLITARY

heels again, and the scene was repeated. The object
of the robber was to seize a leg of the spider, and when-
ever she succeeded in doing this she jerked it free, and
made off with it very rapidly ; but when the owner pur-
sued and caught up with her she relinquished the prize
without a struggle. Why did she? She was the bigger
and the stronger, and possession is nine points of the
law in Waspland as elsewhere ; but conscience made a
coward of her, while the other was strong in her right-
eous cause. After a time we captured the little pirate;
but now the nerves of the rightful owner were completely
upset, and she flew away, deserting the spider for which
she had battled so bravely.

The most interesting thing about fuscipennis is her
habit of biting the legs of her victims. The instinct is
very irregularly developed, since four out of ten spiders
had not lost any legs, while the others had been deprived
of one or two. No one who has watched the wasp can
doubt that the habit is related to the fact that she makes
a very small nest in comparison to the size of her prey.
The spider never went in easily, always requiring to be
shifted and turned and tugged at. There was an especial
tendency to bite at the legs at this point of time, when
the wasp, standing within the tunnel, was trying to drag
the spider down. In one instance she managed to get

220

THE SPIDER-HUNTERS

it past the entrance, but it stuck in the gallery ; and after
working at it in that position for a time she brought it
out, subjected the legs to a severe squeezing, and then
tried again. It was still a very bad fit, but by turning it
about and pulling at it she succeeded in getting it in. It
may be that the object of biting the legs is not to remove
them, but to render them limber so that they will bend
easily. Whatever the process may be, it is repeated at
intervals from the time the spider is captured. As she
carries it, the wasp pauses again and again, now on
bare ground and now in a sheltered place or on some
plant, to renew her efforts at getting the legs into a satis-
factory state.

P. fuscipennis rarely circles about when leaving a
place ; this is unfortunate, since her sense of locality
seems to be particularly weak. She nearly always has to
hunt for the plant upon which she has placed her spider,
and always loses track of her nest when she tries to
bring the spider to it. We once caught her as she was
carrying her spider, and then released her on the same
spot; but she became so much confused that without
our assistance she would never have found it again.

Our acquaintance with Pompilus marginatus began
in the middle of July. She is a small creature, only
half an inch long, and is dressed in black, with a bright

221

WASPS, SOCIAL AND SOLITARY

orange spot on each side of the anterior part of the ab-
domen. We were watching the pretty little Diodonti, as
they filled their holes with aphides, when we saw her
going backward, dragging along a medium-sized spider.
Soon she came to an onion flower that was lying on the
ground. Here she stopped and, after a moment's hesi-
tation, drew her prey in among the blossoms of the
cluster so that it was hidden from view. It was not long
before she came out and began to fly about near the
ground, frequently alighting to poke her head into
cracks and to run again and again into little chance
holes. Never did an insect behave in a more demented
manner, and although there may have been a method
in her madness it was difficult to discover it. No hole
nor cranny pleased her, and back she flew to the onion
to see whether her booty were safe. For fifteen minutes
she ran and flew now here, now there, hurry and anxiety
in every movement, returning frequently to reassure
herself about the spider. Several times she entered a
hole at the base of a weed, not a made nest, but an acci-
dental crevice ; and this spot was at length chosen either
as a temporary or a final resting place for her spider,
since she dragged it from the onion and deposited it
here. We tried to capture the wasp; but having failed
in this, we dug out the spider. It was three inches

222

THE SPIDER-HUNTERS

POMPILUS MARGINATUS

down, the hole being deeper than it looked from the
outside. There was no egg upon it. Evidently the work
had not been finished, for the restless creature returned
fifteen times within an hour to the broken nest, either
for the purpose of laying her
egg or to remove the spider to
another resting-place on her
homeward way.

This was our first specimen
of marginatus, and a month
passed before we met another.
It was while watching some
Bembecidae that we saw the
pretty little orange-spotted worker dragging a small
Thomisid across their nesting-ground. The spider was
so small that she held it in her mandibles well above
the ground, and we speak of her as dragging it only
because she walked backward and acted as though she
were obliged to exert herself. Quite often the spiders
taken by this species are too large to be carried, and
then it is necessary to drag them; this habit is so in-
grained that when it would be much more convenient
to go straight ahead they stick to the ancient custom,
and seem unable to move in any other way. This little
wasp was in a frantic hurry, running backward into the

223

WASPS, SOCIAL AND SOLITARY

Bembex holes and then scrambling out again, until she
had crossed the field and had turned to one side, having
gone, since we first saw her, about fifteen feet. Here
she dropped the spider and began to skim over the
ground - - it could not be called running and yet it was
not flying — until she found a circular hole in the
black earth, which looked as if it ran vertically down-
ward. At the time we thought that this was a nest that
she had made for herself, but we afterward concluded
that it had been excavated by some other creature,
that she had found it and determined to make use of
it, and that she was bringing her prey to the spot with
that end in view. Without entering she rushed back to
the spider, but after carrying it a few inches, dropped
it and ran to take another look at the nest. By this
time, however, she was too much excited to know what
she was about, and for five minutes she scurried over
the ground without finding it. During this time she
picked up the spider four times, carried it a little way,
and then dropped it. The last time she carried it to the
edge of the grass and stowed it there, this being her first
attempt at concealment. She now found the hole again
and brought the spider nearly to it, but by this time she
was perfectly beside herself. The spider was seized
again and again, only to be dropped the next second,

224

THE SPIDER-HUNTERS

while the wasp rushed back and forth between it and
the hole. In time this method of procedure brought
it close to the nest, but it was carried around the edge
once or twice even then. At last, accidentally as it
seemed, it fell in, when the wasp quickly ran in also
and pulled it down. For half an hour she remained in-
side, and when she came out we caught her to make
sure of her identity. As we set her free immediately
we expected her to go to work at covering her nest, but
in this we were disappointed, for she did not return.
We left the place undisturbed from the thirteenth to
the fifteenth of August, when we dug up the nest. The
Thomisid was there, but we could find neither egg nor
larva. The spider was alive, as was shown by a quiver-
ing of the legs. This quivering grew fainter and fainter,
until upon the nineteenth it was scarcely perceptible,
and on the twenty-first the spider was dead. Our first
spider had been stung to death at once, while this one
lived seven days and a half after being stored.

On September first, while out in the bean patch, we
saw a large Lycosid running madly, first in one direc-
tion and then in another. Hovering eagerly and ex-
citedly just above was our marginatus, dashing down
at the spider again and again as it came into view for
an instant, and then circling wildly around until it

225

WASPS, SOCIAL AND SOLITARY

appeared once more. Now she pounced upon the
frightened spider but missed her aim, now she really
grasped it but was shaken off. At last the end came.
The wasp descended upon the doomed spider, and there
was a violent struggle, both the combatants rolling over
and over upon the ground, while all that we could distin-
guish was the flashing of the red upon the body of the
wasp. In an instant it was over, and the wasp rose,
leaving the spider limp and motionless upon its back.
In our other examples of marginatus the spider taken
had been so small that the wasp might easily have held
it and thrust her sting into any spot that she pleased,
but this Lycosid was a different antagonist. Where the
two were so nearly matched, there could have been
but slight opportunity for skillful surgery. In point of
strength the wasp was at a disadvantage, and she
must have come off victor by the quick use of her sting.
Under these circumstances she must have struck when
and where she could, without selecting any particu-
lar spot. That she quite realized the power of her foe
was shown by her next action. With the utmost cir-
cumspection she settled down upon the spider and
made a prolonged and careful examination of the
mouth parts. The investigation was satisfactory, and
without any further stinging she seized the spider by

226

THE SPIDER-HUNTERS

one leg, and this time really dragged it off. It was a
good load for her, and it evidently required all of her
strength to pull it along. Not far away was a lump of
earth, under which the treasure was stowed; and then
began the usual hunting performance, which soon re-
sulted in the discovery of another cavity which had a
very small opening.

She crept in, remained a minute, and then came out
and brought her spider to this new hiding-place. The
head went in easily, but it took a great deal of tugging
to get the rest to follow. At last both spider and wasp
were out of sight, and everything remained quiet for
so long that we began to think that this time we were
really to see the final act in the play. But no; when
the little wasp came creeping out it was only to start
off on another extended tour, in which we did not at-
tempt to follow her. She doubtless selected another
halting-place, for when she returned it was to try to
get the spider out of the hole by pulling at one of its
hind legs. The task, however, was not an easy one. She
exerted all her strength, so that we expected to see the
victim torn to pieces before our eyes, and still it did
not come. At last she seemed to realize that there
was more than one way to accomplish her end, and
turned her attention to cutting away the earth to make

227

WASPS, SOCIAL AND SOLITARY

the opening larger. After a few moments' work she
tried again, and although the passage was still much
too small for convenience the spider was at length
dragged forth, looking much the worse for wear. As
she moved away we alarmed her by lifting some vines
that prevented our keeping her in view, and she flew
up, leaving the spider on the ground. We seized the
opportunity to bend and twist the plants this way and
that so that the ground might be left uncovered. The
changes that we made probably disconcerted her, for
she seemed to lose track of her prey. For over half an
hour she hunted about, circling above the place and
running around and around over the ground. She
often came so close to the spider that we could not
understand why she did not see it. At last it was re-
covered, and again she started off. We tried to follow
her, but the vines were so thick that, in spite of our
efforts, she soon disappeared into the undiscovered
country which we had thus far been unable to penetrate.
Up to this time we had been entirely unable to under-
stand the actions of marginatus, and each new example
added to our confusion instead of clearing it away.
We were inclined to think that she never made a nest
for herself, but caught her spider and then hurried
about for a good place to store it, and that her absurd

228

THE SPIDER-HUNTERS

conduct was the result of an indecision of character
which made it extremely difficult for her to choose a
place and be contented with it. The last part of this
judgment holds true, even now when we know her whole
history, but we have at last learned that she does dig
her own nest.

We had watched a wasp for some time as she car-
ried her spider from place to place, and finally saw
her take it into a crevice among some rough lumps of
earth which she had previously examined. We ex-
pected one of the long spells of eventless waiting to
which she had accustomed us, but on lying down and
peering into the hole we found that there was an open-
ing on the further side, for a ray of light feebly penetrated
the interior. Moving about in this dim illumination
was our wasp, and after a little, we could see, quite
distinctly, that she was digging a hole. This then is
her method - - to find some sheltered hiding-place
where she may secretly make her nest, that no creature
may know where her treasure is hidden.

We have twice seen a marginatus pick up her spider
and fly with it backward for a long distance - - as much
as four or five feet. This recalls the wasp which is said
to fly backward before a moving horse and catch the
flies that are hovering over it.

229

WASPS, SOCIAL AND SOLITARY

P. marginatus is not troubled by any notion as to
the family connections of the spider that she takes.
Anything will do provided she is strong enough to over-
come it and carry it to her nest. The effect of her sting
is quite variable, since in some cases the victim was
killed at once, while in others it was but little affected
in the beginning and lived for eighteen or twenty days.

At eleven o'clock on the morning of a warm day in
mid-August we saw the steel-blue Pompilus scelestus
dragging a big Lycosid across a field. The spider was
sixteen millimeters long and wide in proportion, while
the wasp was but thirteen millimeters long and very
slender, so that the weight of the spider was at least
three times that of its captor. The necessity for going
backward was evident in this case, but the wasp moved
rapidly considering the load that she was dragging.
As she worked her way along she made frequent pauses,
stopping for two or three minutes at a time in some little
hollow, or under leaves or weeds. She spent a good
deal of time, during these pauses, in cleaning herself,
and a good deal of time also in doing something to the
spider which we could not understand. She seemed to
be biting the legs, near the body, beginning with an an-
terior leg on one side and working backward, and then
repeating the operation on the other side. She went

230

THE SPIDER-HUNTERS

through this squeezing process again and again, and
to us it looked as though she might be trying to force
back the juices from the legs into the body preparatory
to cutting them off; but after a time she would seize her
prey and start on again. She had made her way along
in this fashion for some ten feet, when a second wasp
appeared and alighted on a weed near by. This inter-
loper was a trifle smaller than the other, and from her
actions was evidently greatly interested in the paralyzed
spider. When the Pompilus stopped for a moment the
other moved from stem to stem in a stealthy manner
just as a cat stalks a bird. The rightful owner of the
prey was disturbed and dashed at her, driving her away
again and again, but she flew only a short distance and
was soon back, always creeping nearer and nearer to
the spider. We, too, were watching with closest atten-
tion, but our desire was to see the speedy homecoming
of Pompilus and to learn whether she cut off the legs
of her victim; and so, interesting as was the contest
between the wasp and the wasp-inquiline, we decided
to interfere and remove the intruder. This was very
easily accomplished, since the little insect was so intent
upon following the spider that she was oblivious to our
presence, and allowed us to place a bottle over her as
she stood eagerly looking for a chance to advance. Her

231

WASPS, SOCIAL AND SOLITARY

removal gave great relief to the other wasp, as was
manifested by an entire change of manner. Before, she
had been constantly on the lookout, moving only with
the greatest circumspection, but now she relaxed her
vigilance. With the Ceropales in our vial we, too, felt
relieved, and now the path of discovery seemed clear
before us ; but scarcely had things assumed their old
status when a second enemy, a much larger and bolder
Ceropales, threw both the Pompilus and ourselves into
consternation. Again we took the side of our wasp and
drove the other one off, but only to see it return a few
moments later. The Pompilus now flew at it in a most
gallant fashion and pursued it far afield, but when she
came back the enemy was but a few seconds behind
her. Here we again interposed and removed the second
Ceropales from the field of action.

All cause for anxiety being over, the wasp now re-
sumed her journey. Before long she came to a shallow
depression in the ground which was partly sheltered by
an overhanging lump of earth, and under this covering
she dropped the spider and again began to squeeze its
legs. After a moment she removed it to the other side
of the depression, where it was subjected to further
manipulation. Next, her toilet was attended to, and
then the spider was carried back and placed again

232

THE SPIDER-HUNTERS

under the lump of earth. At least ten times was that
limp and helpless creature dragged from one side to
the other of the little depression, a distance of about
two inches, the time between being filled in by the wasp
with cleaning herself and squeezing the legs of her
victim. After forty minutes of this tedious delay the
moment came when she picked up her burden with
renewed determination and started rapidly on her way.
We kept very close to her, but she did not allow our
presence to interrupt her work, and, indeed, paid no
attention to it. After she had gone along for a distance
of about eight feet there was another pause, of only
five minutes this time, and when she resumed her on-
ward march it was in a new direction. Thus far she
had gone almost due south, but now she turned and
went six feet toward the west. Suddenly the spider
was dropped. There was no hole in sight, but the wasp
seemed to feel that some important crisis had arrived.
Her whole manner was excited and flurried, and we
thought that surely we had reached the neighborhood
of the nest. How little we understood her! Her nest was
still far away, and it may be that she had just begun to
realize that the task she had undertaken was too heavy
for her accomplishment — that at her present rate of pro-
gress her strength would be exhausted before she could

233

WASPS, SOCIAL AND SOLITARY

reach her goal. At any rate, something was wrong. The
spider was left unprotected on the ground while she
made a number of long excursions without it, sometimes
being gone as much as fifteen minutes. On coming
back from these trips she would return to the task of
squeezing the legs with such energy and persistence
that we expected to see them drop off. Then she would
run over the ground in all directions, looking under
lumps of earth and stones and poking her head into
every little hole. Was she trying to find some suitable
spot near at hand to take the place of the one which
she had prepared or selected at a distance?

One hour from the time of her arrival at this place,
and two hours from the time that we began to watch
her, she flew away and was gone for an unusually long
time. We can only suppose that when she absented
herself in this way she was visiting the spot to which
she wished to convey her booty. On her return she seemed
to be filled with a new idea, for after climbing to the
top of a tall stout weed that grew near by, she came
down, seized the spider, and tried to drag it up the stem.
Perhaps she meant to lift it to such an elevation that
she could fly with it, but it was too heavy for her and
fell after she had raised it to a height of three inches.
She then flew away again, and on her return we caught

234

THE SPIDER-HUNTERS

her, fearing that she was becoming discouraged and
that she might presently depart to be seen no more.
Had there been any prospect of her solving the diffi-
culty that beset her our patience might have held out
to the end, but this was evidently a case in which there
was a failure of instinct, or intelligence, or whatever
faculty was concerned.

More than a year passed before we had another op-
portunity of solving this problem of scelestus, and the
pleasure with which we hailed her second appearance
in our garden may be easily imagined. This time the
wasp had made her nest, but was not ready to fill it, and
when we first saw her she was running about without
any particular aim in view, although at the time we
supposed her to be hunting. Before long she went and
took a look at the neat round hole which she had made
near the fence that separates the garden from the woods.
The earth that had been taken out either had been
carried to a distance or had been swept away after the
digging was completed, for there was no pile to be seen.
This was at two o'clock of a cloudy afternoon. It may
be that she needed the stimulus of sunshine to make
her hunt, or perhaps she realized that what was left of
the day would not give her sufficient time to capture her
spider and bring it home. At any rate, she spent the

235

WASPS, SOCIAL AND SOLITARY

remainder of the afternoon in making short excursions
around her nest, attended, at a little distance, by a
smaller blue wasp, Pompilus subviolaceus, whose pre-
sence she did not seem to notice. These trips took her
from ten to twenty feet from the nest, each occupying
from fifteen minutes to half an hour. At every return
to the nest she flattened herself out on the ground and
wriggled in the dust, and then dragged herself all
around it in the strangest manner. Perhaps these ac-
tions were indications of pleasurable emotion. We had
seen them once before, in Priononyx atrata just before
she carried a locust into her nest.

At a little after four o'clock she began to investigate,
very carefully, the plants and grasses that immediately
surrounded her hole, showing an especial interest in
one bunch of clover that grew four inches away. Into
this she finally vanished, and peering curiously among
the greenery, we discovered her hanging to a leaf, which
was sheltered by thick foliage on all sides. Here she
remained motionless and probably fast asleep until
sundown, when we left her for the night.

When we went to the garden at eight o'clock on the
following morning, subviolaceus was on hand, but
scelestus was still sound asleep in her leafy bower.
We thought it best to awaken her, for a large spider

236

THE SPIDER-HUNTERS

had spread its web just below, and if the wasp should
drop upon it nothing could save her. We therefore
aroused her gently, whereupon she crept slowly up the
stem and, taking her stand on the highest point, sur-
veyed the world. Then, after stretching herself sleepily,
she made her toilet, cleaning off her wings and legs,
and washing her face with her feet like a cat. When
these duties were finished she walked slowly about for
an hour, visiting her nest every now and then. Sud-
denly, at half past nine o'clock, her whole manner
changed, and seeming very much excited she ran rapidly
along, parallel with the fence, for fifteen or twenty feet,
and then, rising on her wings, flew far away into the
woods. She had evidently gone hunting at last, and
we watched eagerly for her return. She was not suc-
cessful at once, however, for at half past ten she came
back without anything, stayed at the nest for a few
minutes, and then flew to the woods again with the
same excited manner as before. Perhaps she had al-
ready caught her spider at some far distant spot, and
was getting her bearings preparatory to bringing it
home ; but it was half past one when she suddenly ap-
peared, five or six inches from the nest, coming back-
ward through the fence, and dragging a large Lycosid.
This she laid down close by, and began to bite at the

237

WASPS, SOCIAL AND SOLITARY

legs quite after the manner of the wasp we had seen
the year before. Her movements were full of nervous
excitement, in marked contrast to those of the previous
day. Presently she went to look at her nest, and seemed
to be struck with a thought that had already occurred
to us - - that it was decidedly too small to hold the
spider. Back she went for another survey of her bulky
victim, measured it with her eye, without touching it,
drew her conclusions, and at once returned to the nest
and began to make it larger. We have several times seen
wasps enlarge their holes when a trial had demonstrated
that the spider would not go in, but this seemed a re-
markably intelligent use of the comparative faculty.
Her method of work was peculiar. Standing in the tun-
nel with her head down and her abdomen curved under,
she bit the earth loose with her mandibles and pushed
it under her body and beyond the tip of the abdomen.
When a little had accumulated she backed out, holding
it in this way.

While she was thus employed the spider was attacked
by a very tiny red ant, that could not by any possibility
have stirred it. When the wasp caught sight of this
insignificant marauder she fell into a fit of wild fury,
and bending her abdomen under, seized the ant again
and again in her mandibles, and flung it backward

238

THE SPIDER-HUNTERS

against the tip of her sting. The little creature finally
escaped, seeming none the worse for the rough han-
dling to which it had been subjected, while the wasp,
still trembling with excitement, grasped her spider and
rushed off to a distance of several feet, carrying it up
on a weed and depositing it there. The labor of ex-
cavation was then resumed, and after a half-hour's
work the nest was completed to her satisfaction.

Coming up head first, she flattened herself out on
the ground, and sprawling thus, dragged herself all
around it. The spider was now brought to the nest,
being left once on the way while she ran in and out again,
and was taken in after a new and original fashion.
Backing in herself, she seized it by the tip of the abdo-
men and dragged it down without any trouble, since
the legs were gently pushed up over the head and made
no resistance.

In two minutes she emerged from the opening, and
standing on the four posterior legs, with her abdomen
hanging down into the hole, scratched the earth back-
ward with the front legs and mandibles. As it fell in
she pushed it down with the abdomen, and as the hole
filled she raised herself higher and higher on her legs,
still using the tip of the abdomen to work the material
into place.

WASPS, SOCIAL AND SOLITARY

When the filling of the nest was nearly completed,
we caught the wasp, and after taking the spider, threw
back the earth into the hole. Subviolaceus, who had
watched the homecoming from a respectful distance,
now felt that her turn had come, and descending upon
the spot began to dig. Not finding anything, she shifted
her position several times, and worked industriously,
even returning after we had frightened her away.
Sharp says that a Ceropales has been observed to ovi-
posit on a spider, not while it was being carried in, but
subsequently by entering the nest for the purpose ;
and the actions of subviolaceus pointed to similar in-
tentions on her part. We have watched her for an hour
at a time running into the open nests on the Bembex
field, sometimes coming out again directly and some-
times remaining inside for several minutes. It is not
likely that she would utilize the flies of Bembex, but
it may be that she was looking for the Pompelid nests
that are often made in the same locality. Scelestus did
not notice subviolaceus, and it is difficult to see why a
wasp should be disturbed by the presence of a para-
site. In making and storing her nest she is the blind
instrument of an impelling power ; she knows what she
must do, but not why she does it. Her descendants are
in most cases as completely outside of her experience

240

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THE HOME-COMING OF SCELESTUS

THE SPIDER-HUNTERS

as her ancestors, and how should she guess that the
presence of a certain fly or wasp means danger to her
race? Of what happens to her egg after she leaves it
she is so absolutely ignorant that she might easily look
on with serene indifference at the destruction of her
own larva by that of the intruder. In Astata we see, as
might be expected, a calm tolerance of the visits of the
Chrysis fly, but the uneasiness of scelestus herself at
the sight of Ceropales and the valorous defense of Try-
poxy Ion show more highly developed instincts. Bem-
bex, too, deeply resents the presence of parasites, al-
though after the deed is done she feeds their young
without questioning their right to her care. Among
bees, Andrena, and Nomada, which is parasitic upon it,
are said to live on most friendly terms; but in other
genera there is a deep-seated enmity between host and
parasite.

In the literature of the Hymenoptera references have
been made from time to time to certain wasps that cut
off the legs of spiders or other creatures before storing
them away; but observations on the subject have been
rare and not very definite. Brehm, in the "Thier-
leben," says that Agenia punctata builds nests of mud,
and places in each cell one moderately large spider
from which she has first removed all the legs. The

243

WASPS, SOCIAL AND SOLITARY

most interesting notes on the subject have been made
by M. Goureau, who gives an account of finding two
spiders that had been mutilated by wasps, one of them
having had all of the legs cut off, and the other all but
the first pair. At another time a wasp that was flying
near him let fall a spider, which he captured before it
could be recovered by the owner. The wasp escaped,
so that he could not determine the species, but the
spider's legs had been removed. He concluded that in-
stead of stinging the spiders the wasps had mutilated
them so that they could not run away. He does not seem
to realize that death would certainly result from such
an operation.

Vespa germanica often cuts off the wings of a dead
wasp, or even cuts its body into two parts, before flying
away with it, but this is only when the captured insect
is too large to be handled in any other way; and Pom-
pilus fuscipennis sometimes cuts off one or more legs
from her spider, although without any regular method
of procedure.

Agenia bombycina finds a nesting-place to her liking
on our smoke-house, in the crevice between the bricks
and the wooden door-frame, where she makes clusters
of little mud cells, putting one mutilated spider into
each, and storing about one a day. Her locality sense

244

THE SPIDER-HUNTERS

is unusually poor, owing apparently to her intense
nervousness and excitability, but some
individuals are better endowed than
others in this respect.

On a bright morning in the middle
of August we stationed ourselves by the
smoke-house at eight o'clock, and half
an hour later an Agenia began to bring
lumps of earth, working out of sight NEST OF AGENIA
under the door frame. She kept at it BOMBYCINA
steadily, spending three or four minutes in getting a
load and one or two in placing it. At twelve o'clock,
her nest being ready, she flew away to hunt
for a spider. So long as a wasp comes
and goes at frequent intervals time slips
away rapidly, but to keep one's attention
unflagging through hours of watching is
weariness to the flesh. We saw no more
of our Agenia until three, when she ap-
peared, half walking, half flying through
the grass, going forward. Her spider was LYCOSA KOCH",

FOUND IN NEST

held by the spinnerets, and being larger OF AGENIA BOM-
than she was it trailed behind her. On BYCINA
reaching the wall she began to climb ; but the weight of
the spider made her fall again and again, and forty

245

WASPS, SOCIAL AND SOLITARY

minutes passed in wearisome toil before it was safely put
away. The egg having been laid, she began to bring
earth for closing, and we felt thankful that our task as
well as hers was nearly over. She worked slowly now,
taking ten or fifteen minutes for a trip ; but after bringing
in the sixth pellet she took on a livelier air, and before
long we were convinced that she had begun to build
a new cell. For two hours longer we watched her un-
remitting labor, and when we left her at six o'clock she
was flying back and forth as briskly as ever.

Another Agenia, less ambitious, brought her spider
at three o'clock and then went to bed in an empty cell,
head in, tail sticking out. We cut away a section of the
door-frame that covered the spot without disturbing
her slumber. This one could never remember where
her nest was, but had a long hunt for it every time
she brought a pellet ; and when she had caught the
spider she lost herself completely on the brick wall,
going to the very top, and even around the corner
on to the side of the building. Every little while she
would fly back to the grass at the threshold and start
up afresh, and in this way she finally stumbled on
the right spot by accident. This seemed very stupid
of her, as she made many locality studies. Her be-
havior was in striking contrast to little Rhopalum's

246

THE SPIDER-HUNTERS

unerring choice of one tiny pin-hole among hundreds
just like it.

The larva of bombycina cocoons nine days after the
egg is laid. The spiders that we found in the cells were
dead even when taken on the day of storing. There
was no rule about the degree of mutilation, one having
seven legs left, two five, one two, and four none. We
have no doubt that the object of this curious habit is to
save room in the nest.

Chapter X

THE ENEMIES OF THE GRASSHOPPER

EARLY in September a little black Tachytes sud-
denly became very common in the garden. The
first one that we saw was going forwards in a series of
long jumps, carrying a small grasshopper which was
held by the base of the antennae. She soon doubled on
her tracks, and it became evident that she did not know
her way; but after going about in circles for two min-
utes she ran into her nest. When she came out she
spent a long time in circling around, flying close to the
ground in wavy, snaky lines, occasionally alighting to
run a few steps; but in spite of this locality study, ten
minutes later, when she came jumping along with her
second grasshopper, she had lost her nest again and
hunted about just as before, twice going directly over
it without seeing it. While she was thus occupied an-
other wasp of the same species attacked her and tried
to get possession of the grasshopper, but the rightful
owner was able to defend it. At last it was stored away,

248

THE ENEMIES OF THE GRASSHOPPER

and she proceeded to fill the nest, scratching the earth
in with her first legs and working it down with the tip
of the abdomen. She worked quietly but steadily for

TACHYTES

ten minutes, closing the place neatly, and then brought
bits of leaf and pieces of earth to cover it all over.

On the same afternoon we saw another of these wasps
digging her nest, but she was so much disturbed when
we came anywhere near her that we were obliged to
retire. On the next day we saw her astride of a small
grasshopper, jumping along like the one of the day
before. She too had great trouble in finding her way.
When she reached the nest she laid her prey down
while she went inside for a moment, and then, coming

249

WASPS, SOCIAL AND SOLITARY

out, seized it by the antennae and backed in with it,
instead of taking it in forwards as was done in the other
case.

Another wasp of this species carried a much larger
grasshopper, which was so heavy that she could not
jump with it, but was obliged to keep to the ground.
In this case only one was used instead of two, which is
the usual number. This wasp was first seen at a distance
of twenty feet from her nest, and yet she went straight
to the right spot without the least confusion, showing
that some individuals of the species have a better idea
of locality than others.

The nest is a short, shallow tunnel with an enlarge-
ment at the end, within which are placed the grass-
hoppers, on their backs, with their heads in. Earth is
packed solidly into the tunnel, but not into the cavity
at the end.

We took two eggs of this species. Each was placed
across the thorax of the grasshopper at the base of the
neck, on the ventral side. Both hatched at the end of
thirty-six hours from the time they were laid, ate for
three days, and then spun their cocoons. One of them
ate only one small grasshopper, leaving a second one
untouched, while the other finished the large grass-
hopper that formed her sole provision.

250

THE ENEMIES OF THE GRASSHOPPER

The grasshoppers taken from the nests, five in num-
ber, were in all cases alive, there being a quivering of the
mouth parts, and in some cases of the legs also, without
any stimulation. This condition lasted for twenty-four
hours from the time the poison was injected. After
that they became quiet, but remained alive until they
were destroyed by the larvae.

It is a curious thing that in these wasps is found the
perfection of that method of paralyzing the prey which
is so much dwelt upon by Fabre, although from their
habits this fine workmanship is not of the slightest use

NEST OF TACHYTES

to them. They entomb their victims underground,
where the conditions are favorable to their preservation,
and the extremely short period that elapses between

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WASPS, SOCIAL AND SOLITARY

the laying of the egg and the spinning of the cocoon
makes it a matter of indifference whether the grass-
hopper is alive or dead, since in any case it would be
eaten before decomposition set in.

We deserve no credit for discovering a second species,
Tachytes peptonica, for by her loud buzzing, slow flight,
and persistent hovering over the nest she gave us every
assistance in her power. She looks and acts like one
of the large leaf-cutting bees, and this resemblance is
heightened by the fact that the grasshopper which she
carries is frequently of a leaf-green color. Her nest,
which is sometimes on the bare ground and sometimes
in the grass, has no external sign to mark it, and when
with a great deal of fuss and buzzing she descends
and burrows, it closes behind her and disappears from
view, so that unless one marks the exact spot there is
no way of detecting it afterward. On her exit a very
slight amount of scratching closes the hole and leaves
it looking exactly like the surrounding surface; so that
in comparing her work with the protracted labor of
Ammophila and some species of Pompilus in disguis-
ing the locality of the nest, we were struck by the suc-
cess to which she attained with a very trifling amount
of effort.

It takes peptonica thirty or forty minutes to catch

252

THE ENEMIES OF THE GRASSHOPPER

a grasshopper, and at each visit she remains for ten or
fifteen minutes inside the nest. The grasshopper is car-
ried in the mandibles, supported by the second and third
pairs of legs. We never succeeded in opening a nest of
this species, but a grasshopper taken as the wasp was
bringing it home did not die until the sixth day.

In our summer work we often found ourselves wish-
ing that we could be in half a dozen places at once
and could chase several wasps at the same time. Never
did we feel these desires more keenly than on the twenty-
ninth of July, when, after spending the best part of an
hour in watching the hunting of an Ammophila, we were
obliged to choose between following her to a possible
conclusion, and giving our attention to a little jet-black
wasp, Lyroda subita, which we now saw for the first
time. This wasp was running around a bunch of clover
in a nervous, agitated manner, as though she were
oppressed by some great anxiety. The chance of dis-
covering something entirely new decided us to relinquish
our Ammophiline hopes, and we sat down at the feet of
our new teacher.

We could not see anything remarkable about that
bunch of clover, but certainly the spot had some strong
attraction for the uneasy little wasp. She ran off first
in one direction and then in another. She circled about

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WASPS, SOCIAL AND SOLITARY

and made short flights now this way and now that, but
always returned. At last she betrayed the secret of her
interest by descending to the ground and picking up a
small black cricket which had been lying close by all the
time. She flew up into the air with it, but even now did
not leave the neighborhood, continuing to fly about from
place to place, alighting now and again on the bean
plants.

After this performance had lasted for five minutes
she brought her burden back to the same spot that it
had occupied before, laid it down, and without vouch-
safing to us any explanation of her conduct, began to
burrow into the soft earth. She went down head first,
backing out with the dirt, which she carried with the
front legs. While she was thus occupied we defended
her booty against two hunting parties of ants which, at
different times, fell upon it and would certainly have
carried it off if we had not been at hand.

It took the wasp twenty minutes to open the burrow,
although, as we afterward learned, it had been exca-
vated before. At the end of that time she turned around
inside, came out head first, and dragged the cricket
within.

We at once opened the nest, but found it impossible
to follow the tunnel on account of the crumbling of

254

THE ENEMIES OF THE GRASSHOPPER

the earth. Indeed, we almost concluded that we were
doomed to complete failure, for it was not until we had
gone down between six and seven inches that we found, in
a little pocket, our wasp in company with three crickets,
upon one of which was a larva a day or two old. At the
time we knew nothing of the habits of Bembex spinolae,
and we were much astonished to find a wasp which evi-
dently fed her young from day to day.

The contents of the nest were carefully conveyed to our
wasp-nursery at the cottage. The cricket that we had
seen taken in was dead, as was also the one upon which
the larva was feeding. The third one was alive, as was
shown by a rhythmic movement of the palp on the right
side. By the next day, however, this one also was dead.

On the morning of the third day, July thirty-first,
the larva had eaten all of the first cricket and the greater
part of one of the others, leaving only the large hind legs.
Supplying the place of the mother, we killed two more
and put them into the tube. One of these was eight
millimeters long, this being about the size of those which
the wasp herself had caught, while the other was of
another species and much larger, being thirty milli-
meters long. Its size and kind, however, made no differ-
ence to the larva, which attacked this one next, although
there were two small ones yet untouched. It ate only

255

WASPS, SOCIAL AND SOLITARY

half of this big one, however, and then passed on. On
August second we gave it two more small crickets, and
for that day and the one following its good appetite
continued, but on August fourth it stopped eating. We
thought that its larval life must be completed, and ex-
pected to see it spin its cocoon, but something was lack-
ing which we were too ignorant to supply, and on August
fifth it died. It had eaten six small crickets and half of
the large one, which was equal to about two more. Thus
ended our only acquaintance with this interesting little
wasp.

The second week of August furnished such good play
n our garden that island life was neglected; but one
brilliant morning we rowed over to the home of Bembex
and Philanthus, hoping that something new was in store
for us. We were not disappointed, for as we climbed the
crest we met a splendid Chlorion cceruleum dressed in
shining blue, cricket in mouth, plunging down the hill-
side through the long grass. Twenty-five feet below,
she reached her underground home, vanished for two
or three minutes, and then, coming to the entrance,
turned her head from side to side as though listening.
Some indiscreet insect was chirping loudly not far away,
and before long the wasp ran out into the grass, flew to
a stump, dropped to the ground, flew to the top of a tall

256

CHLORION AND THE INDISCREET CRICKET

THE ENEMIES OF THE GRASSHOPPER

weed, dropped again, and ran into a hole. A moment
later she came out, dragging a very limp cricket. An ant
that crossed her path was chased vindictively, and then
the cricket was placed on its back and scraped from
head to foot four or five times with the mandibles. She
then ran a little farther, laid it down again, and re-
peated the operation, after which it was taken into the
nest.

To find ourselves on the track of a lively wasp at the
beginning of her day's work was great good luck, and
as Madam Cceruleum was perfectly fearless and did
her hunting on foot, instead of disconcerting us with
the long flights by which many of our wasps made
the chase hopeless, we had every chance to learn her
ways.

It was a fatal day for the crickets. Between nine
o'clock and one, sixteen had been packed away, enough
to provision three cells, as we knew from former obser-
vations. Her manner was brisk and energetic, as she
ran about poking her head into every likely hole. At
one time we saw her dislodge a cricket which tried to
escape by hiding under some brush. She pursued, there
was a lively scrimmage, and it was pulled out quite limp
and was then held in the mandibles, back up, while she
gave it a prolonged sting under the neck, after which

259

WASPS, SOCIAL AND SOLITARY

it was carried home without further manipulation. At
another time she paused in her home-coming to give the
victim one long squeeze at the neck. The crickets were
placed in pockets, neatly arranged on their backs with
their heads inward and their long legs projecting into
the main tunnel. They were alive when taken, but died
from day to day in the laboratory, the larvae eating
them in this state without criticism.

While we were watching we noticed a much smaller
wasp hovering about, and presently she slipped into
the nest. When the owner returned and found her,
there was a slight commotion in the passage-way, and
then the inquiline appeared, shaking her wings in a
flippant manner, as though she cared nothing for an
encounter with the Big Blue. Instead of coming out
immediately as usual, cceruleum stayed inside for twenty-
five minutes. We should like to think that she was
occupied in finding and destroying the egg of the para-
site, but we have no reason to suppose that she could
recognize that menace to her fortunes.

Cceruleum lives in her nest and enlarges it from day
to day to fit her necessities. On going over to the island
one morning we found a cricket sleeping calmly in the
entrance way, little guessing how dangerous was its posi-
tion. It did not budge until the wasp came creeping up

260

THE ENEMIES OF THE GRASSHOPPER

from below, when it jumped away to a place of safety.
Before the day's hunting began, a long study of the
locality was made on foot, tufts of grass, weeds and
stones being carefully noted, and this accounts for the
ease with which the nest is afterward found.

One July afternoon we saw a little red Tachysphex
tarsata on the Bembex field of the island. She had a
very anxious air, and was running about wildly and
rapidly, holding a small grasshopper with the third
pair of legs. She let it drop four or five times, and when
she picked it up again she seemed to sting it, but of
this we were not quite certain. At last she left it and
began to rush about, investigating the Bembex holes,
entering one of them and perhaps throwing out a little
dirt as though she intended to use it, and then hurrying
off to another. We have no doubt that her confusion
was the result of her having lost track of a hole that
she had made, as was the case with P. quinquenotatus
in one of our earlier observations. The Pompilus, after
a long search, resigned herself to the necessities of the
case and made a new nest ; but this little wasp could not
adjust herself to a break in the system of her instinctive
activities, and at last deserted her prey and disappeared.
We waited for an hour; and then, as she did not re-
turn, we took possession of the grasshopper. It gave no

261

WASPS, SOCIAL AND SOLITARY

response to stimulation and never revived, a very careful
examination later showing that it was quite dead.

On the next morning we again saw this wasp on the
Bembex field. She was looking for a nesting-place, and
when she had selected one she began to work ; the
weather was warm and sunny, so that the Bembecids
were in the full swing of their obstreperous activity, and
perhaps resenting the presence of the little red wasp, or
perhaps in a spirit of teasing, they kept snatching her
up and carrying her off to a distance of two or three
feet. She took these interruptions with the most phi-
losophic composure, hurrying back to her work as soon
as she was released, without any display of resentment.
When the nest was finished, she made a careful locality
study both on foot and on the wing and then flew away.
In twenty minutes she came back, apparently to re-
fresh her memory, for she again made careful notes of
all the points that could help her to identify the place.
She dug a little more and then departed, to return five
minutes later, on foot, with a grasshopper. In spite of
all the precautions she had taken, at this exciting mo-
ment she was unable to remember just where her nest
was, and spent some time in running wildly about, but
when she did find it she went in without delay. We
caught her as she came out, and dug up the grasshopper,

262

THE ENEMIES OF THE GRASSHOPPER

but found no egg, so that she probably would have
brought in a second victim had we let her go. The
tunnel ran in obliquely for an inch and a half, the
pocket at the end being two inches below the surface.

A few days later we saw Larra quebecensis, another
little grasshopper wasp, with the same red abdomen
as tarsata, going to and fro about her nest, occasionally
throwing out a little sand. She ran about near by all
through the afternoon, but was not in a mood for work.
On the next morning at ten o'clock, we found her touch-
ing up the nest a little, after which she left it open and
flew away. In an hour she came leaping along like
Tachytes, holding a small grasshopper in the third legs.
This was placed inside the door while she turned around,
and was then pulled in. She came out immediately,
and in twenty minutes brought a second, and in ten
more a third grasshopper, staying within this time for
some minutes, after which she closed the nest. We took
out the grasshoppers, one of which bore an egg under-
neath, in the middle, in front of the first pair of legs.
The grasshoppers lived for five, six, and seven days, but
the egg did not develop. We once saw a quebecensis
that had laid down her grasshopper while she hunted
for her nest. She was moving in sinuous lines up and
down the face of a cliff, with incredible rapidity ; we

263

WASPS, SOCIAL AND SOLITARY

could not distinguish her, but could see only a black
streak with an occasional flash of crimson. When she
rises on her wings, too, she is wonderfully quick, dis-
appearing as if by magic, it being quite impossible to
even guess at the direction she is taking.

Chapter XI

WORKERS IN CLAY

THE nests of Pelopaeus cceruleus and Pelopaeus
cementarius, our two mud-daubers, are common
under eaves and in other sheltered places, and many a
country boy on opening them has been astonished to
find that they do not contain wasps, but are crammed
with spiders. Let them alone, however, and the wasps
will arrive, for somewhere in the mass is an egg; and
when it hatches the spiders will serve as breakfast, din-
ner and tea for the larva, until the change from the
Arachnida to the Hymenoptera has been accomplished.
Poor spiders ! it is a wonder that there are any left, such
thousands and tens of thousands are destroyed by these
tremendously energetic enemies.

Of what is Pelopaeus thinking as, humming loudly,
she jams her paralyzed and benumbed victims into her
little cylindrical tubes? If only we could get inside of
that little head ! If only we could be wasps for a day,
and then come back and tell about it, how much vain
speculation would be saved ! We can understand her

265

WASPS, SOCIAL AND SOLITARY

when she soars gayly into the blue, the sunshine flashing
from her brilliant wings ; we too have felt the delight of
health and freedom. She is still comprehensible when,
at the close of day, she and her sisters quarrel for the
favorite sleeping-places among the carvings of the porch
pillars ; but we cannot follow her mental processes
when, at the moment of building, she surrenders herself
to the mysterious sway of instinct, doing she knows not
what, but doing it joyously, and preserving through it all
the precious possession of her own individuality. Every
aspect speaks of pleasure as these wasps gather at well
or spring, and, singing contentedly, stand on their heads
to gather their loads of mud. Briskly and gayly they
fly back and forth, pausing at the nest long enough to
pat the soft building material into shape. A single load
makes half a ring at the larger part of the nest or a
whole one at the bottom ; and since one dries before the
next is put on, the contour of each ring is visible when
the tube is done, giving a very artistic effect. This is
only accident, however ; the wasp cares nothing about
the beauty of the structure, for her next step is to daub
the whole with lumps of mud, the walls being thus
thickened and strengthened. About forty loads are
necessary for each cell, and to build and provision one
is a good day's work.

266

WORKERS IN CLAY

It is strange enough that with no one to teach her
Pelopaeus knew how to make her cell; but now she must
do her hunting, and it is stranger still that she should
be impelled to catch nothing but spiders. How does
she know a spider from a fly, and why should she pre-
fer one to the other? Not so unreasonable as some
wasps, however, she demands nothing further than that
her prey shall belong to this great group, and passes
lightly over differences of species and genera. Her
powerful sting fits her to cope with anything she may
meet ; but as the size of the cell must be taken into con-
sideration, and the victim must be carried home on the
wing, she is on the lookout for something not too large.
Here then she ceases to be an automaton, and to some
extent makes use of her wits.

How does Pelopaeus seize her spider ? When and
how many times is it stung? Is the wound given with
discrimination, a certain point in the ganglion being
pricked, so that the spider may be paralyzed, but not
killed? Is there any malaxation?

These were important questions to us, and we were
therefore greatly excited over our first hunt. One of
the blue wasps came flying along, alighted on our cot-
tage wall, and began her search, creeping into corners
and cracks and investigating cottony lumps of web.

267

WASPS, SOCIAL AND SOLITARY

In a few moments a small Epeira strix (the only species
to be found on the cottage) was dislodged, and at once
dropped to the floor of the porch. The wasp paid no
further attention to it, but went on with her search.
Three more spiders, one after the other, were disturbed
and dropped to the floor without being followed. The
fifth one discovered was a little larger than the others,
and was seized by the jaws and first legs of the wasp
before it had time to escape. It was then rolled into a
ball, or at least so it appeared, and stung, then rolled
a little more and stung again, and then carried off. We
had scarcely drawn breath after this performance
when a second wasp appeared. This one dislodged two
spiders, and then caught a third, which was seized and
stung without any rolling, and then instantly borne
away. A third wasp seized the first spider that she
found, and started on her flight at the same moment,
stinging it on the wing.

So the game went on, while we waxed warm with the
excitement and fascination of the chase. As the hours
went by some of the yellow mud-daubers appeared,
adding to the interest of the scene, although we could
not see that their method differed in the least from that
of cceruleus.

Rarely did they succeed in catching a spider until

268

WORKERS IN CLAY

they had dislodged two or three. Sometimes the spiders
were followed as they dropped, and were caught on the
floor, but oftener the wasp let them escape and continued
her search on the wall. At the moment of capture we
could see that she bent her abdomen under and in-
flicted a sting, but although we concentrated our atten-
tion on the point we could not be sure as to just what
part was touched. It is our impression that this first
sting was given anywhere, at random, with the object
of producing a condition of temporary quiet in the
victim, so that the next part of the operation could be
carried on with deliberation.

The second step in the procedure was commonly for
the wasp to alight upon some neighboring object, usu-
ally the branch of a bush or tree, and sting the spider
a second time, being evidently in no haste ; but the
difficulty of following her as she flew, and her habit
of alighting above our range of vision, made it almost
impossible to see just what she did. She certainly re-
mained on the branch for some moments, either resting
quietly or rolling the spider around and around, and
had every opportunity to sting it as carefully as she
wished; but we afterward found that she followed no
exact method, since two thirds of the spiders were
killed at the moment of capture, and most of the others

269

WASPS, SOCIAL AND SOLITARY

died within a week, while a few lived for thirty-five or
forty days. In this study we opened five hundred and
seventy-three cells and handled over two thousand spi-
ders, watching over them from day to day with a mag-
nifying glass, that no sign of life might be neglected.

When Pelopasus has filled her cell, she seals it up and
makes another close to it, clusters of from six to twenty
being found in one spot. Any especially desirable place
is used by great numbers ; and they make a lively scene,
working eagerly at their nests, dashing off for more mud
or bringing in their victims. All animated by the same
compelling instinct, they are still individuals, and the
character of each enters into her work. One picks up
the first spider she sees, no matter how tiny it may
be, and makes twenty-five or thirty journeys before
her cell is filled, while another seems to have a calcu-
lating turn of mind, using four or five big spiders in-
stead of a quantity of small ones. Has she made a note
of the calibre of her cell, and determined to save herself
trouble by looking farther and selecting the largest
ones that will go in?

Most of them place their cells vertically; but a few
prefer the horizontal position, while still others, unde-
cided as to the matter of direction, make clusters in
which some are horizontal and others upright. Occa-

270

WORKERS IN CLAY

HORIZONTAL CELLS OF THE
MUD-DAUBER

sionally there is a remarkable innovation in building-
material, as where in a group of fifteen, four cells in the
centre were constructed of pure white plaster, forming
a striking contrast to the surrounding mud color. One
wasp built an entire cluster after an original fashion,
following the beaten track
until the cell was completed,
and even bringing mud
enough to daub it over, as
her sisters were doing, but
sticking it all in one spot, so
that when the group was
complete irregular lumps
were attached here and there, leaving visible the elegant
architecture of the individual cells. Did she think they
were too pretty to spoil ? or was she merely one of those
radical spirits that rebel against conventionality and
demand change for the sake of change? It is these
variations that furnish Natural Selection with its ma-
terials; but rigid as may be the rules regarding the
non-survival of the unfit, we find that the race of Pelo-
paeus still produces many absent-minded wasps, that
after spending hours in carefully constructing their
nests, seal them up empty, forgetting to put in the
spiders or to lay the egg.

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WASPS, SOCIAL AND SOLITARY

When a cell is sealed, the mother wasp ceases to take
an interest in it, but she has done all that is necessary.
In two or three days the egg hatches, after which the
larva spends ten or fifteen days in eating, and then
spins its cocoon. Here it remains, perhaps for only a
few weeks, — for there are two or three generations in
one season, — or perhaps through the long months of
winter.

Fabre gives a most entertaining account of a French
species of Pelopaeus which nests in the wide-mouthed
chimneys of the peasant. Undisturbed by the steam
of washing day or the bustle of dinner-getting, the wasp
enters the open door, passes unconcerned among the
human inhabitants, and makes her cells against the
smoky bricks, out of reach of the flames. This species
kills her prey at the moment of capture, by which act
she falls in the estimation of Fabre, who respects a
wasp in proportion to the nicety with which she delivers
her sting. He says, however, that at least she follows
a logical method in turning to account these spiders,
menaced with early decay. In the first place the prey is
multiplied in each cell. The piece actually attacked by
the larva is soon a disorganized mass, likely to decay
speedily ; but it is small and is consumed before decom-
position can advance, for when a larva once attacks a

272

WORKERS IN CLAY

spider it does not leave it for another. The others then
remain intact, which is enough to keep them fresh during
the short period of larval life. When, on the contrary,
the prey consists of a single large piece, it is necessary
that the organic life should be maintained, and a special
art must also be observed in eating it. It is well then
that Pelopaeus is inspired to take numerous small pieces.
The egg, moreover, is always placed on the first spider
brought in, whether the storing of the nest is completed
within a few hours, or whether, as in some cases, it
occupies several days; and this M. Fabre considers a
very happy arrangement.

The French Pelopaei differ from ours at nearly every
point. Ours kill only about two thirds of their victims,
many of the others being paralyzed so perfectly that
they live for two or three weeks. Again, ours, instead
of placing the egg upon the first spider, almost invariably
lay it upon the last one brought in. Another point of
difference is that our larvae frequently start in by eating
up the soft abdomens, like children who first devour
the plums in their pudding, returning later to the tough
parts that are left, a rash and reprehensible course of
action of which their better-taught French cousins are
never guilty. When one comes to compare the two sets
of facts furnished by the two groups of species, the

273

WASPS, SOCIAL AND SOLITARY

deductions which Fabre has drawn as to the importance
of the instincts of the French group are seen to be un-
founded. The American species violate nearly every
principle which he considers necessary to their existence,
and yet they flourish and multiply. For our part we
find nothing in the actions of Pelopaeus that needs to
be explained — nothing that is not well adapted to the
conditions under which each species works. The mea-
sure of praise or blame which we mete out to these
depredators is merely a way of saying whether we would
or would not follow their methods in provisioning our
houses and rearing our children. Perhaps we would
always use large spiders and would always have them
fresh; but it is evident that tastes differ, and the matter
is so purely a subjective affair that it will have to go
unsettled. In any event, whether her victims be strong
or feeble, old or young, big or little, fresh or dry, they
certainly serve admirably in enabling Pelopaeus to rear
brood after brood, and to people the different parts of
the earth with abundant representatives of her kind.

Chapter XII

SENSE OF DIRECTION

WE once made a number of experiments to dis-
cover in what way the social wasps came back
to the nest on returning from their hunting expeditions.
Were they endowed with some innate power which
made memory of places unnecessary, and enabled them
to fly in a straight line to any point they wished to reach,
or did their return depend upon the more common-
place method of remembering the appearance of the
countryside ?

One morning at half past eight, we placed a wasp
cage over the opening of a yellow- jacket hole that had
been closed since the night before, and caught fifty-
five workers, after which the nest was again closed, one
of us taking the cage out on to the lake, while the other
remained to watch for their return.

At seven minutes before nine, twenty of the wasps
were liberated an eighth of a mile from shore near the
end of the island. All, without exception, flew toward

275

WASPS, SOCIAL AND SOLITARY

the island and away from the nest. Whether they set-
tled could not be determined. The boat was then
moved an eighth of a mile beyond the island to the
north, where, at ten minutes after nine, the remaining
wasps were set free. They seemed a good deal con-
fused, and flew in all directions. Many returned to the
boat and alighted, but soon flew away again. Two that
settled on the boat were knocked into the water; but
they instantly rose and circled up into the air until out
of sight.

Of the fifty-five wasps that we set free, thirty-nine
returned to the nest by ten o'clock, five of them belong-
ing to the lot that flew to the island, since they soon
found their bearings and came directly home, reaching
the nest before the wasps of the second lot were liberated.

Of the thirty-five wasps that were set free at the sec-
ond point, at least twenty started in wrong directions.
Adding these to the first twenty, we have left only fif-
teen that appeared to know where to look for their
home, and yet thirty-nine reached the nest in a little
more than an hour from the time the first wasps were
set free.

On another morning we caught thirty- eight workers
and took them to a boat-house on the shore of the lake,
in the second story of which was a large room with two

276

SENSE OF DIRECTION

good-sized windows; one looked west over the lake and
away from the nest, the other east toward the nest, and
both were wide open. The west window was the brighter,
but the other was light, the sun being on that side of the
house.

We placed the cage in the middle of this room and
opened the door, stationing ourselves well to one side
so as not to interfere with the movements of the wasps.
They came out very naturally, pausing a moment before
flying, and followed each other so slowly that we could
easily see which window they went out by. Twenty-
two flew through the west window away from the nest,
and sixteen through the east toward the nest.

At another time we took fourteen wasps from the
nest of a different species and carried them seventy-
three yards to the southeast. The cage was opened so
that they could fly out in any direction they chose, and
they all started in a straight line for the nest. Later on
the same day, we took forty-five from this nest, and set
them free one hundred and seventy-six yards to the
south. Seven flew north toward the nest, twenty-one
south, eight west, and seven east, while the other two
circled around as they rose higher and higher, until
they were lost to view. None in this experiment returned
to take a fresh start.

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WASPS, SOCIAL AND SOLITARY

Again, we took twenty-three wasps three hundred
yards southeast of the nest and liberated them in an
open field ; thirteen flew east or south away from the
nest, seven west or northwest toward the nest, and four
returned to the starting-place and seemed unwilling to
venture out again.

These observations show that the two species of
wasps with which we experimented have no sense of
direction in the form of a mysterious additional sense,
nor yet in the form of a power by which they keep a
register of the turns and changes in a journey and are
thus able to retrace their way. Our cage was of wire,
and so open -that they could see all about, as we carried
them from place to place; yet when they flew out, they
most frequently started in a wrong direction and toward
a point that we had not passed. In many instances,
however, these wasps returned to the nest, and it seems
highly probable that as they rose higher and higher into
the air, circling as they went, they discovered some lofty
treetop or other object that had before served them as a
landmark, and that in this way they were able to make
their way home. Bee-keepers know that if young
workers which, in strong hives, pass the first ten or
fifteen days of their lives in feeding the larvae without
going abroad, are taken out and set free only a short

278

SENSE OF DIRECTION

distance from home, they are unable to find their way
back, and perish, while those that have passed beyond
the nursing stage and have begun to do outside work
may be carried long distances away and still readily
regain the nest.

With the solitary wasps we attacked the problem
from the other end. We observed what the social wasps
did in attempting to return to the nest ; with the soli-
taries, we watched them when, after making the nest,
they prepared to leave it to go out into the fields or
woods in search of food or prey, thinking that the pro-
cedure of different species under these circumstances
would afford a clue to the faculty upon which they de-
pended to find their way about. If they were furnished
with an innate sense of direction they would not need
to make a study of the locality of the nest in order to
find the way back, but if they were without this sense
it would be only common prudence to take a good
account of their bearings before going far afield.

The sight of a bee or a wasp returning to its home
from some far distant spot, without hesitation or un-
certainty, is indeed marvelous. When we saw our first
Ammophila perform this feat we were filled with won-
der. How was it possible for her to hunt for hours, in
all directions, far and wide, and then return in a direct

279

WASPS, SOCIAL AND SOLITARY

line to a nest which had been so carefully covered over
that every trace of its existence was obliterated ?

To say that she is a creature of instinct, however, is
not quite fair to her ladyship's intelligence, as a better
acquaintance with her would prove. In reading much
popular natural history one might suppose that the in-
sects seen flying about on a summer's day were a part of
some great throng which is ever moving onward, those
that are here to-day being replaced by a new set on the
morrow. Except during certain seasons the exact op-
posite of this is true. The flying things about us abide
in the same locality and are the inhabitants of a fairly
restricted area. The garden in which we worked was,
to a large extent, the home of a limited number of cer-
tain species of wasps that had resided there from birth,
or having found the place accidentally, had settled there
permanently. To make this matter clear let us suppose
the case of an individual of A. urnaria. In June she
spent her time in sipping nectar from the onion flowers
or from the sorrel that grew on the border of the garden.
In July came the days of her courtship and honey-
moon, and these too were passed in going from flower to
flower, from one part of the garden to another. Many a
day we have followed her when she flew from blossom
to blossom along a row of bean plants, turning, when

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SENSE OF DIRECTION

she reached the end, and wending her way leisurely
back along the next row. Then comes a day when we
see her running over the ground and looking carefully
under the weeds for a good nesting-place. At last a spot
is selected and she begins to dig ; but two or three times
before the work is completed she goes away for a short
flight. When it is done, and covered over, she flies
away, but returns again and again within the next few
hours, to look at the spot and, perhaps, to make some
little alteration in her arrangements. From this time on,
until the caterpillars are stored and the egg laid, she
visits her nest several times a day, so that she becomes
perfectly familiar with the neighborhood, and it is not
surprising, after all, that she is able to carry her prey
from any point in her territory in a nearly direct line
to her hole — we say nearly direct, for there was almost
invariably some slight mistake in the direction which
made a little looking about necessary before the exact
spot was found.

After days passed in flying about the garden — going
up Bean Street and down Onion Avenue, time and
time again — one would think that any formal study
of the precise locality of a nest might be omitted; but
it was not so with our wasps. They made repeated
and detailed studies of the surroundings of their nests.

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WASPS, SOCIAL AND SOLITARY

Moreover, when their prey was laid down for a moment
on the way home, they felt the necessity of noting the
place carefully before leaving it.

Of the species that catch their prey before making
the nest we have good examples in Pompilus quinqueno-
tatus, the tornado wasp, and fuscipennis, the Pompilus
with the red girdle.

The tornado wasp may make her nest anywhere from
one to ten feet from the spot on which she has deposited
her spider, while fuscipennis never goes more than four-
teen inches away. During the process of excavation
both of these wasps pay several visits to the spider, and
frequently they have difficulty in finding it. As an ex-
ample of this kind of trouble we give a diagram of the
course followed by an individual of fuscipennis after
she had finished her nest, in trying to find her spider
and in bringing it home. This and the other similar
diagrams that are given are reductions of large tracings
that were made on the spot. Although not absolutely
correct they are exact enough for all practical purposes,
since wherever there is an error it is necessarily in the
direction of making the path pursued by the wasp
appear shorter and less complex than it really was.
The individual in question had placed her spider on a
cucumber vine which lay on the ground, not hidden by

282

SENSE OF DIRECTION

leaves, but fully exposed to view. The nest was only
eight inches away, but when it was finished and the

COURSE FOLLOWED BY POMPILUS FUSCIPEN-
NIS IN FINDING HER SPIDER AND IN
RETRACING HER STEPS TO THE NEST 1

wasp went to bring the spider, she found it only after
a search of three minutes ; and then when she went

1 The nest being completed, the wasp went skimming over the
ground as indicated by the line, until the spider, which had previ-
ously been stung and placed upon a leaf, was found. She then
dragged it some distance beyond the nest to the point 2, from which
place she took it to the nest.

283

WASPS, SOCIAL AND SOLITARY

back to the nest she at first passed to one side and went
some inches beyond, so that she had to retrace her
steps.

Marchal notes that some wasps are very unskillful
in finding their way about, showing by their errors and
hesitations not only that they have no sense of direction,
but that they are badly served by their memory and by
what senses they have. He draws this conclusion from
his own observations, one of which had for its subject
Pompilus seriaceus, which nests, conveniently for him,
in the walls of the rustic summer-house which he uses
for a laboratory. A wasp of this species, having caught
her spider, had a most wearisome experience in getting it
to the nest, which had been previously excavated near
the ground. She first carried it straight up, not only
passing the opening, but going to the very top of the
wall. Realizing that she had gone wrong, she laid it
down, and after a prolonged hunt up and down, to
the right and to the left, found the nest ; but on leav-
ing it again to go for the spider, she started in exactly
the wrong direction, down instead of up; and not until
forty minutes had been spent in searching alternately
for spider and for nest did she finally bring the two
together.

The best evidence that wasps depend upon a know-

284

SENSE OF DIRECTION

ledge of the place in returning to their nests is given by
the pains they take to. acquire that knowledge. When
Sphex ichneumonea was ready to dig her nest, she had
great difficulty in finding a place that suited her. Many
a spot was merely looked at and passed by, while others
that seemed more attractive were left after they had
been excavated for a little way. At last, the nest dug,
she was ready to go out and seek for her store of pro-
visions ; and now came a most thorough and systematic
study of the surroundings. The nests that had been
partly made and then deserted had been left without
any circling. Evidently she was conscious of the differ-
ence and meant, now, to take all necessary precautions
against losing her way. She flew in and out among the
plants, first in narrow circles near the surface of the
ground, and now in wider and wider ones as she rose
higher in the air, until at last she took a straight line and
disappeared in the distance. Very often, after one
thorough study of the topography of her home has been
made, a wasp goes away a second time with much less
circling or with none at all.

If the examination of the objects about the nest
makes no impression upon the wasp, or if it is not re-
membered, she ought not to be inconvenienced nor
thrown off her track when weeds and stones are removed

285

WASPS, SOCIAL AND SOLITARY

and the surface of the ground is smoothed over; but
this is just what happens. Aporus fasciatus entirely
lost her way when we broke off the leaf that covered
her nest, but found it, without trouble, when the missing
object was replaced. All of the species of Cerceris were
extremely annoyed if we placed any new object near
their nesting-places. One Ammophila refused to make
use of her burrow after we had drawn some deep lines
in the dust before it. The same annoyance is exhibited
when there is any change made near the spot upon
which the prey of the wasp, whatever it may be, is de-
posited temporarily. We learned from experience how
important it was not to disarrange the grass or plants
on such occasions. The wasps are in many cases so
prudent as to conceal their booty among the leaves ; and
this made it very inconvenient to keep our eyes upon
the captured prey, as was quite necessary if we wished
to follow it on its travels. To avoid the discomfort of
lying on the ground or of twisting the neck at some im-
possible angle for half an hour at a time, we sometimes
gently moved the intercepting objects to one side ; but
even such a slight change cost us dear in time and pa-
tience, as it threw the wasp out of her bearings and made
it difficult for her to recover her treasure. We recall
one exceedingly warm day in September when we were

286

SENSE OF DIRECTION

delayed in this way for forty minutes, when she would
have seized the spider and gone on her way without a
pause had we not interfered.

Very often the wind would shake the plant so that
the spider or caterpillar would fall to the ground. Under
these circumstances the wasp was not at all disconcerted,
but, on not finding her prey where she had left it, dropped
at once to where it was lying. This is probably only an
extension of their ordinary habits. A wasp that takes
spiders learns to follow them as they drop from the web
on being disturbed. In this they are evidently guided
by sight, but perhaps they are also aided by the sense
of smell under other conditions, — to the extent, at least,
of recognizing the place upon which their prey has lain.
With so much to build upon, it is easy to see how natural
selection may have perfected the habit. We are delaying
a long time over details, but we feel that to invoke an
unknown sense is permissible only after a careful study
of the daily life of the animals in question has left the
problem unsolved.

Among the wasps that first make the nest and then
provision the larder, Astata bicolor is one of the most
interesting. She makes a permanent abiding-place,
and probably uses it until all of her eggs are laid. It
is evident that since she comes and goes many times

287

WASPS, SOCIAL AND SOLITARY

during the several weeks of her occupation, she does
not need to make a prolonged study of the environment
at every departure. Her first survey, just after the nest
is completed, is most thorough; and, as a usual thing,
when she first comes out on each succeeding morning,
she reviews the situation more or less carefully. Indi-
viduals differ in this respect, however, some studying
their local habitat much more than others. In this as

well as in all other mat-
ters our observations
are in complete accord
with those of Sir John
Lubbock, who says :
"Indeed, many of my
experiences seem to
show not only a differ-
ence of character in the
different species of ants,
but that even within the limits of the same species

1 The wasp flew from nest to I, paused a moment, then flew back;
then to 2, paused and flew back ; then to 3, paused, then to 4, paused
and flew back to nest ; flew to 4, 5, 6, 7, 8, and 9, pausing at each spot,
and flew back to nest along 10; flew, successively, along n, 12 and
13, resting at the spots designated; from 13 she circled around nest
in direction of arrow points and departed.

288

LOCALITY STUDY OF ASTATA BICOLOR

SENSE OF DIRECTION

there are individual differences between ants, just as
between men." 1

This little bug-hunting Astata bicolor made her
study in a different way from Sphex ichneumonea. She
first flew from the nest
to a spot near by and
settled there, returning,
after a moment, to the
nest, or else flying to
another resting-place.
After pausing in a
number of places (in
the case of the one fol-
lowed in the diagram,
thirteen), she finished
by a rapid zigzag flight.
Another wasp of this
genus, unicolor, differed from bicolor in not returning
to the nest from the different resting-places, and in

1 Ants, Bees, and Wasps, p. 95.

2 The continuous line shows the course walked over by the
wasp, the short marks at right angles representing resting-places;
the broken line indicates flight. Line i shows the first study, lead-
ing back to the nest, and line 2 the second, ending in flight and
departure.

289

LOCALITY STUDY OF ASTATA UNI-
COLOR 2

WASPS, SOCIAL AND SOLITARY

walking from one to another of them instead of flying,
although the last part of the study was made on the

wing.

Cerceris deserta was one of the wasps that objected
strongly to our presence, and she also made a great deal
of fuss about leaving her nest. Nearly all the species
circle before leaving a spot to which they intend to
return, but deserta begins her flight with a series of

SECOND LOCALITY STUDY OF A. UNICOLOR !

short zigzags in the form of a half circle on one side
of the nest. C. nigrescens, too, begins with semicircles,
while C. clypeata flies entirely around and around the

1 The continuous line shows the course walked over by the wasp ;
the short marks at a right angle indicate resting-places ; the broken
line indicates flight.

290

SENSE OF DIRECTION

opening. The contrast between the deliberate move-
ments of Astata and the rapid flight of Cerceris is very
striking.

We have now given a sufficient number of instances,
from widely separated genera, to show the care that is
taken by wasps to acquaint themselves with the sur-
roundings of their nests. It has also been shown that
in spite of all this care they frequently have trouble in
rinding their way about. All these facts have led us to
conclude that wasps are guided in their movements by
their memory of localities. They go from place to place
quite readily because they are familiar with the details
of the landscape in the district they inhabit. Fair eye-
sight and a moderately good memory on their part are
all that need be assumed in this simple explanation of
the problem.

Chapter XIII

INSTINCT AND INTELLIGENCE

OUR study of the activities of wasps has satisfied
us that it is impracticable to classify them in any
simple way. The old notion that the acts of bees, wasps,
and ants were all varying forms of instinct is no longer
tenable, and must give way to a more philosophical
view. It would appear to be quite certain that there
are not only instinctive acts but acts of intelligence as
well, and a third variety also — acts that are probably
due to imitation, although whether much or little in-
telligence accompanies this imitation is admittedly dif-
ficult to determine. Again, acts that are instinctive in
one species may be intelligent in another, and we may
even assert that there is a considerable variation in
the amount of intelligence displayed by different in-
dividuals of the same species. We have met with
such difficulty in our attempts to arrange the activities
of wasps in different groups that we are forced to the
conclusion that any scheme of classification is merely
a convenience, useful for purposes of study or generali-

292

INSTINCT AND INTELLIGENCE

zation, but not to be taken for an absolutely true ex-
pression of all the facts. This kind of perplexity is well
understood and allowed for in all morphological work,
but it has never been fully realized in the study of habits.
The explanation is not far to seek. The habits of but
few animals have been studied in sufficient detail to
bring out the evidence that there is as much variation
on the psychological as on the morphological side,
although this field seems fresh and inviting when com-
pared with the researches of the laboratory.

The necessity of interpreting the actions of animals
in terms of our own consciousness must be always with
us. To interpret them at all we must consider what our
own mental states would be under similar circumstances,
our safeguard being to keep always before us the pro-
gressive weakening of the evidence as we apply it to
animals whose structure is less and less like our own.

We arrange the activities of the wasps that we have
studied into two groups, Instincts, and Acts of Intelli-
gence, it being understood that these classes pass by
insensible stages into each other, and that acts that
are purely instinctive when performed for the first time
are probably in some degree modified by individual
experience. In this classification the question of origin
is not considered. The facts are grouped under the

293

WASPS, SOCIAL AND SOLITARY

two heads, the inferences that they warrant being left
for later consideration. Under the term Instinct we
place all complex acts that are performed previous to
experience and in a similar manner by all members of
the same sex and race, leaving out as non-essential, at
this time, the question of whether they are or are not
accompanied by consciousness. Under Intelligence we
place those conscious actions which are more or less
modifiable by experience. It is this power that enables
an insect to seek, accept, refuse, choose, — to decline to
make use of this or to turn to account some other thing.
Many writers prefer the term Adaptation for these ac-
tivities, and it possesses certain advantages. With these
definitions in mind, let us group the activities of wasps
under the two heads.

With the wasps of the genus Pelopaeus we were pre-
sent on several occasions when the young emerged from
the pupa case and gnawed their way out of the mud cell.
They were limp, and their wings had not perfectly
hardened, and yet when we touched them they tried to
attack us, thrusting out the sting and moving the abdo-
men about in various directions. These movements
were well directed, and, so far as we could observe,
quite as perfect as in the adult wasp. Stinging, then,
is an instinctive act.

294

INSTINCT AND INTELLIGENCE

The particular method of attack and capture prac-
ticed by each species in securing its prey is instinctive.
Ammophila pricks a number of gan-
glia along the ventral face of the
caterpillar; Pelopaeus, we believe,
stabs the spider in the cephalo-
thorax, and probably the several
species of Pompilus do the same.
Astata bicolor adopts the same tac-
tics in capturing her bugs, while it
is said of the flycatchers that they
commonly overcome their victims
without using the sting. It is by in-
stinct, too, that these wasps take
their proper food supply, one PARALYZED SPIDER HUNG
worms, another spiders, a third UP ON SORREL BY QUIN-

flies, moths., or beetles. So Strong QUENOTATUS WHILE SHE

DIGS HER NEST

and deeply seated is the preference,

that no fly robber ever takes spiders, nor will the ravisher

of the spiders change to beetles or bugs.

The mode of carrying their booty is a true instinct.
Pompilus takes hold of her spider anywhere, but always
drags it over the ground, walking backward; Oxybelus
clasps her fly with the hind legs, while Bembex uses the
second pair to hold hers tightly against the under side

295

WASPS, SOCIAL AND SOLITARY

of her thorax. Each works after her own fashion, and
in a way that is uniform for each species.

The capturing of the victim and caring for it before
the hole is made, as in the case of P. quinquenotatus, or
the reverse method, pursued by Astata, Ammophila,
Bembex, and others, of preparing the nest before the
food supply is secured, is certainly instinctive ; as is
also the way in which some of these wasps act after
bringing the prey to the nest. For example, S. ichneu-
monea places her grasshopper just at the entrance to
the excavation, and then enters to see that all is right
before dragging it in. Under natural conditions this
order is never varied, although the wasp can adapt
herself to different circumstances when occasion de-
mands. Again, we see Oxybelus scratching open her
nest while on the wing, and entering at once with the
fly held tightly in her legs. Each way is characteristic
of the species, and would be an important part of any
definition of the animal based upon its habits.

The general style of the nest depends upon instinct.
Trypoxylon uses hollow passages in trees, posts, straws,
or brick walls; Diodontus americanus, a member of the
same family, always burrows in the ground, as do Bem-
bex, Ammophila, and Sphex. In the case of Trypoxylon
the passage may be ready for use or may require more

296

INSTINCT AND INTELLIGENCE

or less preparation ; the instinctive part is the impulse
that requires the insect to use a certain kind of habi-
tation. Any one familiar with T. rubrocinctum would
never look for her nest in standing stems or under
stones; to use Mr. Morgan's test, he would be willing
to bet on the general style of the dwelling-place. All of
these acts are similarly performed by individuals of the
same sex and race, not in circumstantial detail but quite
in the same way in a broad sense. Variation is always
present, but the tendency to depart from a certain type
is not excessive. In Cerceris the burrow is tortuous,
this style of work being common to many species in the
genus, and very characteristic. No Sphex nor Ammo-
phila constructs any such tunnel. The adherence of
all the members of a species to a certain style of archi-
tecture is, then, due to instinct.

The spinning of the cocoon, in those species in which
the larva is protected in this manner, and its shape, are
instinctive. We find that closely allied species in the
same genus make very different cocoons, as is seen in
T. rubrocinctum and T. bidentatum. Some wasps spin
no such covering for themselves. It is a well-known
fact that silkworms sometimes omit the spinning of a
cocoon ; but this does not affect the argument, since
the descendants of these individuals make the charac-

297

WASPS, SOCIAL AND SOLITARY

teristic covering. Such cases are probably due to indi-
vidual variation or perhaps to atavism, this throwing
back being not uncommon among forms that are well
known.

Not all of the instinctive acts here enumerated are
displayed by each species studied, although they are
common to most of them. We have doubtless overlooked
some activities that should come under this head, as
we have not made a thorough study of any sufficient
number of species to make a final settlement of the
matter.

As we have seen with Ammophila and Pelopaeus,
faults of instinct are not uncommon, but of all our wasps
the one that shows the greatest aberrations is Pompilus
biguttatus. The sandy beach of Lake Michigan is a
favorite nesting-ground with this species, and is the
scene of many a bold robbery, since they are unprin-
cipled little wretches and

"... the good old rule

Sufficeth them, the simple plan

That they should take who have the power

And they should keep who can."

We once found an unusually tiny biguttatus vainly
trying to drag a large Epeirid which her sting had re-
duced to helplessness. It was as though a feeble child

298

INSTINCT AND INTELLIGENCE

should try to move the body of an elephant. The little
wasp clasped one of the spider's legs firmly in her man-
dibles, and then with braced feet and the wildest flutter
of wings made gallant but futile attempts to get it
started. Now she lost her hold on the ground, and wings
and legs were all whirling desperately in the air. Now
her feet grasped a loose ball of earth, and, feeling that
something was moving, she renewed her efforts. The
pellet was drawn nearer and began to rotate around
the wasp, while she seemed to be under the impression
that she was moving forward. After a few minutes of
vigorous exercise, she paused, perhaps to see how she
was getting on, and the bit of earth rolled away; so
that when the attack was renewed, it was under the old
discouraging conditions. She was the impersonation of
perseverance and energy; but after half an hour (no
one knows how long she had been at it before we came)
she gave it up, and with many reluctant circlings flew
away. It was probably experiences of this kind that
developed in some of her relatives the habit of digging
the grave under the victim, and thus saving the trouble
of transportation.

At another time, we saw a biguttatus trying to run
backward with a little bit of a spider, which she had
lifted from the ground and was carrying in her man—

299

WASPS, SOCIAL AND SOLITARY

dibles,-- trying to run backward, because it is the rule
with this genus to move in that way when encumbered
with a load, it being easier to drag a heavy spider than
to pick it up and go forward. The wasp in question
was drawn in two directions. Instinct made her go
backward, although in this particular case it was need-
less, while she felt a constant desire to turn and go
straight ahead. As a result she waltzed slowly over the
sand in a series of overlapping circles, her head turned
toward every point of the compass in succession, a kind
of progress most amusing to the lookers-on.

Biguttatus is not strong enough to fly when laden,
but it is the habit of the species to climb backwards to
the top of every obstacle in the path, and from this
vantage point to gain time by taking a downward flight
in the direction of the nest. It is only in the case of
tall, smooth-stemmed plants and grasses that the ad-
vantage gained is enough to repay the trouble of climbing,
and we have often thought that the notion costs the wasp
more trouble than it is worth, — as was certainly the case
with one comical little creature that carried the idea to
the extreme of folly. Not only did she scale objects in
her way, but just as old Dr. Johnson felt that he had
to touch every tree and post as he walked along, so
when this wasp saw, out of the corner of her eye, a

300

INSTINCT AND INTELLIGENCE

stone or a plant three or four inches to one side, it called
upon her to climb, and climb she did, although she was
obliged to leave her proper path to do it.

It is obviously more difficult to distinguish actions of
intelligence than of instinct. One must be familiar with
the normal conditions of the insects in question before
he is able to note those slight changes in the environ-
ment that offer some opportunity for an adaptation of
means to ends, or before he is competent to devise ex-
periments which will test their powers in this direction.

We find two classes of intelligent actions among the
Hymenoptera which are sufficiently distinct to be con-
sidered separately, although, like all natural groups,
they grade into each other. The first of these includes
those actions that are performed by large numbers in a
similar fashion under like conditions, while in the sec-
ond class each act is an individual affair, — as where a
single wasp, uninfluenced in any way by the example
of those about it, displays unusual intelligence in grap-
pling with the affairs of life. Examples of the first class
are found in such modifications of instinct as are shown
by Pelopaeus and other wasps in the character of their
habitations. Pelopaeus, instead of building in hollow
trees or under shelving rocks, as was the ancient custom
of the race, now nests in chimneys, or under the eaves

301

WASPS, SOCIAL AND SOLITARY

of buildings. We have found T. rubrocinctum taking
advantage of the face of a straw-stack that had been
cut off smoothly as the cattle were fed through the win-
ter. The same power of adaptation is shown by Fabre's
experiment with Osmia, in which he took two dozen
nests in shells from a quarry, where the bees had been
nesting for centuries, and placed them in his study
along with some empty shells and some hollow stems.
When the bees came out, in the spring, nearly all of
them selected the stalks to build in as being better suited
to their use than the shells. All of these changes are
intelligent adaptations to new modes of life, serving
to keep the species in harmony with its surroundings.
The same thing may be seen when a number of social
wasps work together to replace the roof of their nest
when it has been torn off.

An instance of the second class is seen in one of our
examples of Pompilus marginatus. This species, while
searching for a nesting-place, leaves its spider lying on
the ground or hides it under a lump of earth, in either
of which positions the booty is subject to the attacks
of ants ; the wasp in question improved upon the custom
of her tribe by carrying the spider up into a plant and
hanging it there. We have now and then seen a queen
of Polistes fusca occupy a comb of the previous year

302

INSTINCT AND INTELLIGENCE

instead of building a new one for herself, — showing a
better mental equipment than her sisters who were not
strong-minded enough to change their ways, and so built
new nests alongside of unoccupied old ones which were
in good condition. In Bembex society it is good form
to close the door on leaving home, but sometimes a
wasp will save time by leaving the entrance open. This,
however, is a doubtful case, as the advantage would,
perhaps, be more than balanced by the exposure of the
nest to parasites.

Some years after our first experience with Pompilus
scelestuswe saw a wasp of this species carrying her spider
home. She dropped it close to the nest, and looked
meditatively, first at the hole and then at the spider. It
was unquestionably going to be a very tight fit, but if
she could get it in that would be an advantage; so after
a moment she seized it by the tip of the abdomen and
backing down tried to pull it after. Tug - - tug I No, it
would not go down, and scelestus pushed it out and
carried it to a place of safety up among some clover
blossoms. She then washed and brushed herself neatly,
and took several little wralks, so that it was fully fifteen
minutes before she began to enlarge her nest. All that
time she must have carried in her little scrap of a mind
the idea of doing a necessary act which was outside of

303

WASPS, SOCIAL AND SOLITARY

her ordinary routine ; and we noted with interest that the
change when it was made accomplished exactly what
was needed, — the spider went in, but not too easily.

In an experiment with a French Sphex which has
the habit of laying her cricket down at the threshold,
and going inside for an instant before dragging it in,
Fabre took advantage of the moment that the wasp
was out of sight below to move her prey to a little dis-
tance, with the result that when the wasp came up she
brought her cricket to the same spot and left it as be-
fore, while she visited the interior of the nest. Since he
repeated this experiment about forty times and always
with the same result, it seemed fair to draw the con-
clusion that nothing less than the performance of a
certain series of acts in a certain order would satisfy
her impulse. She must place her prey just so close to the
doorway; she must then descend to examine the nest;
and after that she must at once drag it down, any dis-
turbance of this routine causing her to refuse to proceed.
We once found a Sphex ichneumonea at work storing
her nest, and thought it would be interesting to pursue
Fabre's method and find out whether she were equally
persistent in following her regular routine. We allowed
her to carry in one grasshopper to establish her normal
method of procedure, and found that, bringing it on the

3°4

INSTINCT AND INTELLIGENCE

wing, she dropped it about six inches away, ran into the
nest, out again and over to the grasshopper, which she
straddled and carried by the head to the entrance.
She then ran down head first, turned around, came up,
and seizing it by the head, pulled it within. On the
following day, when she had brought a grasshopper to
the entrance of the nest, and while she was below, we
moved it back five or six inches. When she came out,
she carried it to the same spot and went down as before.
We removed it again, with the same result, and the
performance was repeated a third and a fourth time,
but the fifth time that she had found her prey where we
had placed it she seized it by the head, and going back-
ward dragged it down into the nest without pausing.
On the next day the experiment wras repeated. After
we had moved the grasshopper away four times, she
carried it into the nest, going head foremost. On the
fourth and last day of our experiment, she replaced the
grasshopper at the door of the nest and ran inside seven
times, but then seized it and dragged it in, going back-
ward. How shall this change in a long-established
custom be explained, except by saying that her intelli-
gence led her to adapt herself to circumstances? She
was enough of a conservative to prefer the old way, but
was not such a slave to custom as to be unable to vary it.

305

WASPS, SOCIAL AND SOLITARY

"It hath been an opinion," says Lord Bacon, "that
the French are wiser than they seem, while the Spaniards
seem wiser than they are." We leave it to our readers
to determine whether the wasps are wiser than they
seem or seem wiser than they are.

INDEX

AGENIA, mutilation of spiders,

243* 247-'
bombycina, 244.

Ammophila, 1 5 ; stinging habits of
American and French species,
28 ; Fabre's conclusions con-
trasted with ours, 52 ; sleeping
habits noted by Banks, 1 1 7.

gracilis, great distance over

which prey is carried, 46 ; failure
of instinct, 46.
- polita, 50.

urnaria, 18; sense of locality,

20 ; individuality, 22; using a
pebble as a tool, 38.

vulgaris, losing her way, 46.

yarrowii, Williston's notes on

habits, 40.

Aphilanthops frigidus, 167; los-
ing her way, 171; method of
capturing queen ants uncertain,
174.

Aporus fasciatus, 80 ; habit of
filling up partly made nests,
82 ; depends upon close pack-
ing to keep spider quiet, 83 ;
contrast betwreen two individ-
uals, 84.

Ash mead, W. H., on European
species of Oxybelus, 78.

Astata bicolor, locality study, 288.

unicolor, locality study, 290.

Banks, Nathan, observation on
sleeping habits of Ammophila,
117.

Bates, H. W., on habits of Mone-
dula signata, 136.

Belt, Thomas, on locality study of

Polistes carnifex, 60.
Bembex labiatus, note on locality

sense by Bouvier, 124.
rostrata, account of habits

by Wesenberg, 139; note on

locality sense by Marchand,

125.

spinolae, 119; less numerous

A. S •

progeny than other wasps, 120 ;
habit of feeding young from
day to day, 120 ; quarrelsome
habits, 129; tolerance of para-
sites, 132; number of parasitic
larvae found in nests, 133; ex-
periment to determine number
of nests visited by female at one
time, 139; teasing Tachysphex,
262.

Bouvier, note on locality sense of
Bembex labiatus, 124.

Brehm, on mutilation of spiders
by Agenia punctata, 243.

Brues, on sleeping habits of Prio-
nonyx atrata, 118.

Cerceris clypeata, 147 ; locality
study, 149 ; experiments on
stinging habits, 151.
-deserta, 152; locality study,

153-
fumipennis, 142.

nigrescens, 142.

' Ceropales, following Pompilus

scelestus, 231.
Chlorion coeruleum, 256.
Crabro interruptus, 102; locality
study, 105.

3°9

INDEX

Crabro lentus, 101 ; both flies and
bugs found in nests, 101.

sexmaculatus, 99 ; takes both

flies and gnats, 101.

stirpicola, 106 ; contrasted

with other wasps as to manner,
1 06; works night and day to
finish nest, 108.

wesmasli, said to take both

flies and bugs, 101.

Dunning, S. W., on finding flies
alive in nests of Bembex, 135.*

Fabre, J. H., on automatically
perfect instincts of Ammophila,
52 ; on French species of
Sphex, 69 ; on the habits of
Bembex, 134 ; on Philanthus
apivorus, 162 ; on French
species of Pelopaeus, 273.

Goureau, on mutilation of spiders
by wrasps, 244.

Larra quebecensis, 263.

Lubbock, Sir John, on individu-
ality in ants, 288.

Lyroda subita, 253; feeds her
young from day to day, 255.

Marchal, Paul, on poor locality

sense of Pompilus seriaceus,

284.
Marchand, observation on locality

sense of Bembex rostrata, 125.
Monedula signata, locality study

noted by Bates, 136.
Mutilation of spiders by wasps,

243-

Odynerus, variation in nesting

habits, 95.
anormis, position of egg in

nest, 91.

- capra, 94.
conformis, position of egg,

91.

Odynerus perennis, 89.

reniformis, position of egg,

90.

vagus, wanness, 94.

Oxybelus quadrinotatus, 75; me-
thod of carrying fly, 80.

Passolocus annulatus, 87.
Pelopaeus, 265 ; individuality, 270 ;

forgetfulness, 271 ; difference

between French and American

species, 273.
Philanthus apivorus, sucks honey

from bee, 162.
punctatus, 1 54 ; habits of

colony, 1 56 ; experiments on

stinging habits, 162; nesting

habits of males, 166.
ventilabris, 166.

Plenolocus peckhamii, 95 ; stalk
invaded by bees and other
wasps, 96.

Polistes carnifex, locality study
noted by Belt, 60.

Pompilus biguttatus, unreasoning
conduct, 298.

fuscipennis, 216; afraid of

ants, 219; biting legs of spider,
220 ; sense of locality, 221.

marginatus, 221; capturing

spider, 225; method of digging
nest, 229.

quinquenotatus, 197; con-
fined to one species of spider,
202 ; nest invaded by small
ants, 202 ; hangs spider on
plant while nest is being made,
204; robs her neighbors, 211:
loses her way, 214.

scelestus, 230 ; bites legs of

spider, 230 ; pursued by para-
sites, 231 ; sleeping habits, 236.

seriaceus, poor locality sense

noted by Marchal, 284.

subviolaceus, following sce-

lestus, 236.
Priononyx atrata, note on sleep-
ing habits, 1 1 8.

310

INDEX

Rhopalum pedicellatum, 73 ;
strong power of localization,

73-
rubrocinctum, 74.

Social wasps, general habits, 3 ;
color sense, 5 ; sense of smell,
8 ; affecting plant distribution,
1 1 ; number in one nest, 12.

Solitary wasps, general habits, 1 5.

Sphex, habits noted by Fabre,

69.

ichneumonea, 56 ; nests be-
gun and deserted, 56; locality
study, 58 ; intelligence, 305.

Tachysphex tarsata, 261.
Tachytes sp. ?, 248.
peptonica, 252.

Trypoxylon, immense numbers of
spiders destroyed, 195.

- albopilosum, 190.
bidentatum, 194.

— rubrocinctum, 180; protec-
tion of nest by male, 181 ; male
sometimes assists in storing
nest, 182; order in which eggs
hatch, 1 80.

Vespa germanica, 13.

- maculata, 13.

Wesenberg, on habits of Bem-

bex rostrata, 139.
Wheeler, W. M.,on capture of ants

by Aphilanthops f rigidus, 1 76.
Williston, S. W., on habits of

Ammophila yarrowii, 40.

fiitersi&e press

Electrotyped and printed by H . O. Hoitghton &* Co.
Cambridge, Mass., U. S. A.

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