52 ' INSECTS NOXIOUS TO AGEICULTUKE. 



Mytilaspis pomicorticis , Riley; Fifth Rep. State Entom., 



Missouri, p. 95. 

 Mytilaspis pomorum (Bouche), Signoret; loc. cit., 1870, 



p. 96. 

 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 -j^in. 



Male puparium not known in New Zealand. In America it 

 is statedf 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 antennae present. At the edge of each 

 segment two or three strong spines. 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 spinnerets j numbers of orifices 

 variable (see below) ; a few single spinnerets. 



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 Cf oyster-shell bark-louse of the apple." It 

 is the commonest, apparently, of the Diaspidinse ; 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 Reaumur 

 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 noiratre." Mr. Comstock calls it " ash-grey." In 

 reality the colour varies somewhat with that of the bark of the tree, 

 t Conistock; Eep. of Entom., U.S. Dept. of Agric., 1880, p. 325. 



