I have tried as much as possible to avoid scientific names, but the
misfortune is that there are hardly any popular names in use which can be
attached for certain to any particular species, and unless this can be done
it is of no use using vague names like the "Carpenter Bee", the "Mason
Bee", etc. There are many carpenter bees and many mason bees, and though
their habits may be alike in this one particular they differ among
themselves in the way they use their tools, and it is necessary to know
which one we are talking about. It is a common thing to hear people
inveighing against Latin names, etc., but they forget that there are no
English ones in use, and what is more important, that Greek and Latin names
are common property to all nations, so that we can all know what we are
talking about, whereas if we call an insect by an English name and the
Russians {56} call it by a Russian name, the difficulty of coming to a
mutual understanding is very great. This is only an aside to justify the
use of classical names. I quite feel that for popular use in this country a
good series of English names might be useful, but we have not got one, and
it would require a great deal of care and thought to frame a nomenclature
which would really be useable by the persons who require it.
I have made these remarks here because _Osmia_ is a genus whose members
vary very much in their habits, and some species of which, like sensible
beings, adapt their habits to their surroundings, so that no name such as
carpenter bee, etc., would apply to all the species, or, as a rule, even to
one. _Osmia rufa_ especially adopts several methods of nesting. This little
bee is clothed more or less all over with yellowish hairs; it is compact in
shape like all the other species of _Osmia_, and like them collects its
pollen on the underside of the body. It may sometimes be seen flying up and
down the walls of a house looking for a crevice to build in, but it is not
the least particular as to where to form its cells. In one memorable case
the female selected a flute {57} which had been left in a garden-arbour.
The bee constructed fourteen cells in the tube of the instrument,
commencing its first cell a quarter of an inch below the mouthhole. The
flute is preserved in the Natural History Museum at South Kensington. At
other times this species burrows in the ground, at others it makes its
cells in crevices of old walls; it has been known to build in a lock, and
is said sometimes to inhabit snail shells. Other species of _Osmia_ almost
always burrow in banks, but in no case does a habit seem to be uniformly
adopted by a species. One well known and rare species, _Osmia leucomelana_,
is a regular bramble-stick species, tunnelling down the pith in the centre
of the stalks, but I once found it to my surprise in fair numbers nesting
in a sandy bank. Other species again, as a rule, select snail shells to
build in; they find an old disused shell lying about in some sheltered
place and adapt it to their purposes, commencing their cells singly in the
narrow whorls of the shell and side by side as they approach its mouth,
i.e. if the shell be a wide-mouthed one like the common garden snail
(_Helix aspersa_). F. Smith, who gives a very interesting account of these
{58} creatures in his _Catalogue of British Hymenoptera in the British
Museum_, mentions a case where the bee finding the larger whorls of the
shell too wide constructed two cells across the whorl. Another very
interesting case given by Smith is of a nest of many cells of the rare
_Osmia inermis_ (which in his days was known as _Osmia parietina_). A slab
of stone, 10 inches by 6, was brought to him with 230 cocoons of this
_Osmia_ attached to its under side; when found in the month of November,
1849, about a third of them were empty; in March of the following year a
few males made their appearance and shortly afterwards a few females, and
they continued to come out at intervals till the end of June, at which time
he had 35 cocoons still unopened; in 1851 some more emerged, and he opened
one or two of the closed ones and found that they still contained living
larvae; he closed them up again, and in April, 1852, examined them and
found the larvae still alive; at the end of May they changed to pupae and
appeared as perfect insects, the result being that some of the specimens
were at least three years before reaching maturity. {59}
There is a nest of yet another style adopted by one of our species (_Osmia
xanthomelana_). This is formed of a series of pitcher-shaped cells made of
mud, constructed at the roots of grass. The species which makes it is rare
and seems to have its headquarters on the coasts of Wales, although it has
occurred in the Isle of Wight and elsewhere. This species also is not
constant in its habits, as it has been known to make its cells underground.
A very curious habit was noticed some years ago by Mr. Vincent R. Perkins
in another species of this genus (_Osmia bicolor_; pl. D, 28); the species
nests in the ground or in snail shells, but, in the case under his
observation, Mr. Perkins found that the little bees covered up all the
snail shells in which they had built their cells with short pieces of
"bents" so as to make a little hillock over each about two or three inches
in height, somewhat resembling a miniature nest of _Formica rufa_, the
large horse ant, each mound containing hundreds of pieces. This is the only
record I know of this habit, which must entail a large amount of labour for
the bee.
These varying habits in the same species {60} show pretty clearly that
these little creatures are not driven by any blind instinct in the adoption
of their methods of nest building: they appear to have a distinct power of
choice and adaptation according to their environment, unless of course it
can be shown that the offspring of, say, a snail shell inhabitant follows
its parents' habits, and that that of a ground borer does the same--but
even that would not explain the case given by F. Smith, and quoted above,
where an _Osmia_ had filled up the whorls of a shell and then, finding the
final whorl too large, placed two cells horizontally to fill it: that seems
to indicate distinct design on the part of the bee and would be hard to
explain as due to instinct. Unfortunately, with the exception of a very
few, the species of _Osmia_ are rare in this country, so that few
opportunities are available for studying their habits, which are certainly
amongst the most interesting of any genus.
[Illustration: PLATE D.
24. _Anthophora pilipes, male._ 25. _Anthophora pilipes, female._ 26.
_Melecta armata, female._ 27. _Anthidium manicatum, female._ 28. _Osmia
bicolor, female._ 29. _Bombus terrestris, female._ 30. _Bombus lapidarius.
female._ 31. _Psithyrus rupestris, female._
[_face p. 61._ ]
{61}