OAK SCALE-INSECTS. 99 
other citrus plants, ou olive, pear, apricot, plum, pomegranate, Oregon 
asb, bitter-sweet, apple, eucalyptus, sabal palm, California coffee, rose, 
cape jessamine, Habrothmus elegans / and elsewhere upon an Australian 
plant known as Brachceton, and also upon a heath. It preferably attacks 
the smaller twigs of these plants, and the young usually settle upon the 
leaves. 
The development of this species is very slow, and it seems probable 
that there is only one brood in a year. Specimens observed by Mr. 
Alexander Craw at Los Angeles, which hatched in June or July, began 
to show the characteristic ridges only in November. Mr. Craw has 
seen the lice, even when quite well grown, move from twigs which had 
become dry and take up their quarters on fresh ones. 
Although carefully looked for, the males, like those of so many other 
Lecanides, have never been found. 
A dark-brown bark-louse has been sent me from Florida, on live oak, 
holly, oleander, orange, and one or two unknown plants, by Dr. R. S. 
Turner, of Fort George, which appears to be identical with Lecanium 
olece. It is, however, by no means as abundant or injurious in that 
State as in California. 
Enormous quantities of the eggs of the black scales are destroyed by 
the chalcid parasite Tomocera californica* described on p. 368 of this 
report. Particulars as to the work of this parasite are given at the 
same place. Upon oue occasion (August 25, 1880), I found within the 
body of a full-grown female a lepidopterous larva, which was very similar 
in appearance to the larvaB of the species of Ddkruma described in ray 
last report as destroying bark-lice. The specimen, however, was lost, 
and no more have been found since. 
A number of beetles of the genus Latridius were found under scales 
which had been punctured by the Tomocera, but probably would not 
destroy the live insect. Many mites were found feeding upon the eggs 
and young. The infested trees were also swarming with the different 
species of lady bugs (Coccinellidce). (Comstock.) 
Adult female. — Dark brown, nearly black in color; nearly hemispherical in form r 
often, however, quite a little longer than bread; average leugth from 4 mm to 5 imn - 
average height, 3 mm . Dorsum with a median longitudinal carina and two transverse 
cariuse, the latter dividing the body into three subequal portions; frequently the 
longitudinal ridge is more prominent between the transverse ridges than elsewhere, 
thus forming with them a raised surface of the form of a capital H- The body is 
slightly margined ; outer part of the disk wiih many (18 to 30) small ridges which 
extend from the margin half-way up to center of dorsum. Viewed with the micro- 
scope, the skin is seen to be filled with oval or round cells, each with a clear nucleus, 
the average size of the cells being from .05 mm to .06 mm in length, while the nuclei 
average .02 mm in diameter. The antenna are long and 8-jointed, the two basal joints 
short ; joint 3 longest, joints 4 and 5 equal and shorter, joints 6 and 7 equal and still 
shorter, joint 8 with a notched margin and almost as long as joint 3. Legs rather 
"This parasite is now known as Dilophogaster californica Howard, Mr. Howard Sav- 
ing changed the name Tomocera on account of its similarity to Tomocerus in Thysanura. 
