Tachina-like fly, and several species of another genus
of flies, Anthrax, together with several beetles, such as the Meloe
(Fig. 16), Stylops (Fig. 17, male; 18_b_, female; _a_, position in the
body of its host), and Antherophagus prey upon them.

[Illustration: 17. Male Stylops.]

The power of boring the most symmetrical tunnels in solid wood reaches
its perfection in the large Virginian Carpenter bee (Xylocopa Virginica,
Fig. 19). This bee is as large as, and some allied exotic species are
often considerably larger than, the Humble bee, but not clothed with
such dense hairs. We have received from Mr. James Angus, of West Farms,
N. Y., a piece of trellis from a grape vine, made of pine wood,
containing the cells and young in various stages of growth, together
with the larvae and chrysalids of Anthrax sinuosa (Fig. 20), a species of
fly parasitic on the larva. The maggot buries its head in the soft body
of the young bee and feeds on its juices.

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

[Illustration: 18. Female Stylops.]

[Illustration: 19. Carpenter Bee.]

"The tunnels are sometimes taken possession of by other bees and wasps.
I think when this is the case, the Xylocopa prefers making a