SCALE-INSEOTS. 21 
may often be found, and it is noticeable that where it abounds the 
eggs of the Coccid are often shrivelled or empty. It is not im- 
probable that this Acarus may feed on the eggs. It appears to 
belong to the genus Tyroglyphus, a mite which is not usually 
carnivorous ; but Mr. A. Michael, an authority on mites, seems 
to be uncertam whether Tyroglyphus may not make a meal of 
the Coccid.* No others amongst the Diaspidine appear to be 
directly attacked, nor any of the Lecanidine; but amongst a 
number of Dactylopius glaucus on a leaf there may often be seen 
a minute caterpillar, apparently covered with many tufts of hair. 
This is the larva of the common ladybird (Coccinella), a beetle 
which, in both the larval and perfect states, feeds on Aphides, 
Coccids, and other insects. The larva may sometimes be seen 
holding a Dactylopius in its powerful jaws and devouring it. 
Another larva, smooth and without hairs, performs the same 
functions—it is the young of a small dipterous fly, apparently 
one of the Syrphide, insects also predatory; but this seems to 
be rare. In America, similar larvee are said to feed upon the 
“black scale ” (Lecanium olee). In this country, as far as is 
yet known, Lecanidee are not directly attacked by the lady- 
birds. 
But this direct warfare by other animals is of small conse- 
quence. A more important check on the increase of many 
Coccids is afforded by the indirect action of minute hymeno- 
pterous insects, which make use of them as receptacles for their 
eggs. This plan is adopted by several Hymenoptera, of the 
families Chalcididee, Ichneumonide, Proctotrupidee, &c. They 
do not devour their prey; they allow it to live that they may 
live on it. By means of their long ovipositor they pierce its 
body, and deposit in it an egg. As the victim grows the ege 
matures, changes into a larva, and still remains in the body of the 
Coccid ; changes again into a pupa, and by this time the Coccid 
is at liberty to die, for the parasite has no further use for it ex- 
cept as a shelter; then, when the proper time arrives, the perfect 
fly emerges and departs. All Coccids are by no means equally 
subject to this system. In the United States, according to Mr. 
L. O. Howard,t parasites are found in nearly all genera 
Diaspidine, Lecanidine, or Coccidine. In this country, as far 
as SUS gates shows at present, the ee are the most 
a cqsi Journ. Royal Micros. Soc., Feb., 1885, 
¥ Hepeat of the Entomologist, U.S. Dep. of Agric, uy 1880, pp. 350-371. 
