220 MISC. PUBLICATION 4 2 4, U. S. DEPT. OF AGRICULTURE 



April 17, 1922; Q. robxn\ Funchal, Madeira, A. de Moronha. April 

 1923 ; English oak. Department of Agriculture Grounds, Washington, 

 D. C, H. Morrison. July 11, 1924; Webster Grove, Mo., L. Haseman, 

 September 10, 1925; Santiago, Chile, C. E. Porter, November 25, 1926; 

 Q. robur var. monstrosa ciwullata, Berlin, Germanv, intercepted at 

 Washington, D. C, W. T. Owrey, January 27, 1930; Q. robur. Berlin, 

 Germany, intercepted at Washington, D. C, K. G. Cogswell, January 

 27, 1930; Q. pedunculated tho?nasii, Germany, intercepted at Wash- 

 ington, D. C, W. B. Wood, February 8, 1930; from a Mr. Bartlett, 

 September 22, 1932, no further data; Q. sessilis var. mespilifolia, 

 Berlin-Dahlem. Germany, intercepted at Washington, D. G. J. M. E. 

 Adams, March 4, 1936. 



This widely distributed species is well known for its destructiveness. 

 It is closely related to quercicola. 



ASTEROLECAXIUM VENTRUOSUM (Maskell) 



(Fig. 78, Q, R; fig. 79, A-C) 



Described by Maskell in 1895 as Plarwhonia ventruosa (70, p. 63). 



Habit. — ''This insect forms for itself depressions or pits in the bark, adapted 

 to the convexity of its ventral surface; and, when it is lifted out, there remain 

 slender, white, cottony trails, denoting the spiracular regions." {10. p. 63.) 



Test of female. — "Test of adult female green, waxy, flat or sometimes slightly 

 concave. The green colour is in the test itself, and not due to the insect showing 

 through it. Form of test broadly elliptical, or with a very slight posterior 

 tapering. Fringe pink or white." (10, p. 63.) 



Adult female. — Circular, posterior end slightly produced : 0.75 mm. in diameter. 



Margin : 8-shaped pores mostly in a double row but about posterior 16 pores in 

 an irregular single row, terminating about one-half length of an apical seta from 

 setal bases, posterior pores 11 m long and 7 wide, others 12-13 n long and 8 wide, 

 about a pore's width apart where single, and from a pore's width to twice a 

 pore's length apart where double, the 2 rows less than a pore's width apart : 

 quinquelocular pores in a single row interrupted at anterior end opposite 2 

 8-shaped pores and terminating 4-7 8-shaped pores from end of row of those pores, 

 less numerous than corresponding 8-shaped pores near end of row, usually twice as 

 numerous as 8-shaped pores of nearer row elsewhere ; disk pores along dorsal 

 row of 8-shaped pores, terminating sometimes before and sometimes beyond end 

 of row of those pores and less numerous than they are ; disk pores also occurring 

 ventrad of quinquelocular pores, this row terminating anterior to bases of apical 

 setae, the pores as numerous as 8-shaped pores of nearer row. 



Dorsal surface : Minute 8-shaped and disk pores fairly numerous ; tubular ducts 

 27 (i long. 



Ventral surface: Antenna sharply conical, apex spinelike, with 1 seta appar- 

 ently shorter than diameter of antenna ; 2-4 quinquelocular pores between antenna 

 and margin ; beak apparently with 1 pair of setae ; spiracle with bar fairly broad, 

 expanded at inner end, atrium slightly enlarged and containing 3-7 quinquelocular 

 pores, 14-18 similar pores extending from spiracle to body margin in an irregularly 

 single row; multilocular pores, totaling 91 and with 7-11 loculi. apparently 

 arranged in 7 complete rows and 1 interrupted row, the latter anterior to posterior 

 spiracles, the number in each row not readily determinable but posterior row 

 apparently with 14. penultimate row with 9, next with 13, next with 11. next 

 with 19, next with 12, next with 9, and anterior row with 4; a few scattered, 

 dark-rimmed 8-shaped pores ; submarginal 8-shaped pores in a single row terminat- 

 ing near penultimate row of multilocular pores, about as numerous as corre- 

 sponding marginal 8-shaped pores of nearer row ; submarginal setae in a complete 

 row terminating near posterior pair of marginal 8-shaped pores ; 2 pairs of setae 

 in posterior row of multilocular pores and 1 pair in each of the next 2 rows. 



Apex of abdomen : Notch present ; setae, apical 65 /a long, interapical 7.2 ,u long, 

 inner ventral 7.2 fi long, outer ventral 9 n long ; anal ring with 6 setae 28 /j. long 

 and with an inner row of 6 and an outer row of 14 pores, divided on dorsal and 

 ventral sides ; ventral surface of apex weakly sclerotized close to notch, slightly 

 reticulate. 



