MISSOURI BOTANICAL GARDEN BULLETIN 89 
tion of the pseudo-bulbs will reveal the damage done, in 
the form of small holes bored for its exit. On cutting the 
bulbs in half large cavities are disclosed, showing the full 
extent of this injury. In Plate 21 may be seen the effect 
of the insect, the plants in figs. 2 and 3 being grown at the 
Garden for experimental purposes. In their natural state 
the orchids are stronger and are able to withstand these 
attacks without any material damage. Under cultivated con- 
ditions, however, their growth is more or less restrained, and 
unless careful precautions are taken, an attack by these in- 
sects results in the final destruction of the plants. 
The Adult Fly—In the “American Gardening,” Vol. 
XXI, the following description is given: 
“The perfect insect or fly is black, and has clear, shining 
iridescent wings. The female is about one-seventh of an 
inch long, while the male is considerably smaller, being only 
about one-tenth of an inch in length. The head and thorax 
are rough and unpolished, the microscope showing them to 
be covered with tiny pits, from each of which little bristles 
or hairs project. The abdomen is black, smooth, polished 
and shining, and is without hairs except on the smaller last 
segments. The abdomen of the female is pointed and 
somewhat wedge-shaped beneath, while that of the male is 
small, being not more than half the length of the female 
abdomen and terminating bluntly or abruptly. Under the 
microscope the sexes may be readily separated by the 
antennae. In the female most of the joints are about the 
same size and shape, being symmetrical and connected to- 
gether by inconspicuous pedicels; while the male antennae 
are somewhat longer, the chief joints being longer and ab- 
ruptly tapering to a slender neck or pedicel at the anterior 
ends, and lacking symmetry by. being much more swollen 
on one side than on the other. The whorls of hair or bristles 
are very much longer than on the female antennae. 
“The legs at the joints are red, the thighs being black, the 
middle portion yellowish or reddish, except on the hind 
pair—where they are blackish, and the feet (tarsi) are pale 
or dull white and tipped with minute dark claws. 
“The female is provided with a long and extremely slender 
ovipositor, which it inserts into the tissue of the plant when 
depositing its eggs. When not in use this ovipositor lies 
quite concealed by a groove and protecting sheaths.” 
Larva.—The little footless larva is white, a little less than 
a sixth of an inch in length when full grown. This is the 
feeding period, when the growths of the pseudo-bulbs are 
tunneled. From this it develops into a pupa and is black 
