8 BULLETIN 838, V. S. DEPARTMENT OF AGRICULTURE. 



hederas (Vallot), and Aspidiotus ehrhomi Coleman. None of these 

 have been noted doing any considerable damage. 



Still other associated insects of various orders are: Phymaiodes 

 nitidus Lee, Atimia confwsa Say, Trachykele Mondeli Mars., the 

 cypress moth {Argyresthla. cupressella Wals.), the cypress cone- 

 borer (Cydia cupressana Kear,), a horn-tail wasp (Sirex calif ami- 

 cus Ashm.), the arborvita? plant-louse (Lachmella tujaftlina Del 

 Guer.), and an undetermined tussock moth. 



FOOD PLANTS. 



The known food plants of the cypress bark scale are: Monterey 

 cypress (Cupressus macrocarpa Hartw.), Arizona cypress (C. ari- 

 zonica Greene), Guadalupe cypress (C gwadalupensis Wats.), and 

 incense cedar (Libocedms decurrens Torr.). On one other tree, a 

 deodar cedar (Cednis deodara Loud.), at Santa Rosa, Calif., a dead 

 male was found in its cocoon. 



It seems strange that the scale insect should not occur on all 

 species of cypress if it -will infest two trees as different as Monterey 

 cypress and incense cedar, yet Italian and Oriental cypresses, two 

 varieties of Cupressus sempervirens, are immune to the attack of this 

 insect. They have been found in many instances in close proximity 

 to infested Monterey cypresses and entirely free from the scale insect. 

 In one case, in the Benicia Cemetery, 27 cypresses formed a square 

 about a plot. Two-thirds of these were Monterey cypresses, with 

 every third tree an Italian cypress, touching a Monterey cypress on 

 each side. Every Monterey cypress was infested and dead or dying, 

 while not a scale could be found on the Italian cypresses. 



Specimens of Himalayan cypress (C. torulosa Don.), Macnab cy- 

 press (C. macnabiana Murray), funeral cypress (0. fumebris Endl.), 

 Sargent cypress (O. sargentii Jepson), and Port Orford cedar 

 (Chamaecyparis lawsoniana (Murr.) Pari.) have been examined, 

 although not in large numbers, within the infested areas, and no 

 cypress bark scales could be found upon them. 



DESCRIPTION.! 



THE EGG. 



Egg (PI. IV, A), immediately after being deposited, regularly oval, smooth, 

 and shiny, of a -transparent pale yellow color, with eyes of embryo visible 

 through membrane as two dark spots near one end. Average length of seven 

 eggs 0.34 ; mm. ; width 0.14. 



LARVA. 



FIRST INSTAE. 



Young larva? (PI. IV, B) of both sexes alike. Pale yellow in color, with 

 long, flat, oval bodies 0.43 mm. in length, 0.20 mm. in width. Antennae (PI. V, 



1 The following detailed description of all stages from the egg to adult, both male and 

 female, were made from living and freshly mounted material collected during the study 

 of the cypress bark scale. 



