52 INSECTS NOXIOUS TO AGRICULTURE. 
Mytilaspis pomicorticis, Riley; Fifth Rep. State Entom., 
Missouri, p. 95. 
Mytilaspis pomorum (Bouché), Signoret; loc. cit., 1870, 
p. 98: 
N:Z. Trans,, Vol. XI., 1878, p. 192. 
The common apple-scale. 
(Plate V., Fig. 5.) 
Female puparium usually brown,* sometimes white; elon- 
gated, mussel-shaped, convex, slightly curved, sometimes straight ; 
length, about =,in. 
Male puparium not known in New Zealand. In America it 
is statedt to be small, “straight or nearly so, and with the 
posterior part joined to the remainder of the scale by a thin 
portion which serves as a hinge.” 
Adult female greyish, yellowish, or white; elongated, seg- 
mented. Rudimentary antenne present. At the edge of each 
segment two or three strong spies. Abdomen ending in two 
large lobes, with two others much smaller on each side; the 
median lobes are trifoliated. Between and beyond the lobes 
some spines. Five groups of spimnerets; numbers of orifices 
variable (see below) ; a few single spimnerets. 
Male unknown in New Zealand and Europe, doubtful in 
America. Colour stated by Riley (Fifth Missouri Report, p. 95) 
as “ translucent corneous-grey.” 
Habitat in New Zealand—On apple, pear, plum, peach, 
apricot, lilac, ash, thorn, sycamore, cotoneaster, and other 
plants, passim. 
An introduced European species, known in America and 
elsewhere as the “ oyster-shell bark-louse of the apple.” It 
is the commonest, apparently, of the Diaspidine ; and does great 
damage in orchards. 
This species has been referred to by many writers under the 
specific name “ conchiformis;” some authors include it under 
the genus Aspidiotus, others under Coccus, and one—Réaumur 
—under Chermes. In the Quarterly Journal of the Royal 
Microscopical Society, February, 1885, Mr. A. Michael refers 
to it as Coccus (Mytilaspis) pomicorticis. 
The groups of spinnerets have been stated above to be 
* Dr. Signoret says, “ brun noirdtre.”’ Myr. Comstock calls it ‘“ash-grey.” In 
reality the colour varies somewhat with that of the bark of the tree. 
} Comstock; Rep. of Entom., U.S. Dept. of Agric., 1880, p. 325. 
