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



A. quercicola, as redescribed by Signoret on oak from Paris, and here 

 accepted as the true quercicola (Bonche), is distinct from variolosum, 

 with which it was synonymized by Cockerell in 1899 (21, p. 269), by 

 Sanders in 1909 (8Jx, p. J/31), and by Lindinger in 1912 (61, p. 360). 



HaUt. — Living on bark, in shallow or deep pits. 



Test of female. — Nearly circular, 1.25-1.7 mm. long and 1-1.5 wide, usually 

 1.5 mm. long and 1.4 wide ; slightly to distinctly convex dorsally, with posterior 

 tip flattened, usually with faint transverse striations ; slightly or distinctly 

 convex ventrally ; usually greenish, sometimes brownish yellow, transparent, 

 often shiny, sometimes slightly punctate in lateral areas; marginal filaments 

 same color as test, slightly shorter at posterior end than elsewhere ; elliptical larval 

 exit in dorsal surface at margin. 



Adult female. — Nearly circular, 0.95-1.5 mm. in diameter, posterior end some- 

 times slightly produced. 



Margin: 8-shaped pores in a single row terminating one to three (usually 

 one) times the length of a posterior pore from bases of apical setae, the posterior 

 pores 9-10 ix long and 6 wide, the others 12 \x long and 6 wide, from the width 

 to the length of a pore apart; quinquelocular pores in a single row terminating 

 at a point 10-28 (usually around 20) pores before the posterior pair of 8-shaped 

 pores, the row complete, or interrupted opposite 1-20 8-shaped pores at anterior 

 end, the quinquelocular pores in the proportion of 1 to each 8-shaped pore anter- 

 iorly and 1 to each 8-shaped pore and 1 opposite the interval between every 2 

 8-shaped pores elsewhere, except sometimes 2 to each 8-shaped pore near spiracular 

 pore bands, in this case the row almost double. 



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

 tubular ducts 32 jx long. 



Ventral surface: Antenna thimble-shaped, with 2 setae nearly as long as 

 diameter of antenna ; beak with 2 pairs of setae ; spiracular bar expanded at 

 inner end, roughly triangular ; a group of 8-16 quinquelocular pores outside 

 spiracular opening and a double or triple row of similar pores extending from 

 there toward body margin, this row often becoming 5 or 6 pores wide at the 

 margin, usually a total of 45-65 pores in group and row combined ; multilocular 

 pores in 4 complete rows, posterior row with 8-13 pores (usually 10 or 11) , each of 

 next 2 with 5-10 (usually 7-9), and anterior with 4-7 (usually 5 or 6), or a total 

 of 23-38, the pores with 6-10 loculi ; a loose group of 7-10 dark-rimmed 8-shaped 

 pores each side of mouth parts, some scattered on anterior end, others tending 

 toward arrangement in 2 transverse rows posterior to beak ; submarginal 8-shaped 

 pores in an irregularly double row terminating near the posterior row of multi- 

 locular pores, usually 2 opposite every other marginal 8-shaped pore, but oc- 

 casionally in a slightly different proportion ; submarginal setae in a complete row 

 terminating near the penultimate pair of marginal 8-shaped pores ; 2 pairs of 

 setae in posterior row of multilocular pores, 1 pair in each of the other rows, and 

 1 pair before the anterior row. 



Apex of abdomen : Setae, apical 32-40 fx long, interapical 8-10 n long, ventral 

 8-9 fi long ; anal opening ventral, circular, its margin sclerotized, 2 setae, 3 //. 

 long, on anterior edge. 



Larva. — Nearly elliptical; posterior end sometimes narrowed. 

 Margin: With 28 8-shaped pores, axes of all longitudinal: 2 pairs of setae 

 at anterior end. 



Dorsal surface: 8-shaped pores in a submedian row of 1-4 (usually 1 or 2) and 

 a lateral row of 9, on each half of body, or a total of 20-26, practically same size as, 

 or slightly larger than, marginal pores ; disk pores near lateral 8-shaped pores. 



Ventral surface: Antennal setae, I, 1; IV, 1; V, 0; VI, 2 long, 2 stout, 2 fairly 

 stout, 2 slender ; antennal bases about one-half length of antenna apart ; beak 

 setae, 3 pairs apical ; anterior spiracle with 2 quinquelocular pores or with 1 

 quinquelocular and 1 trilocular pore, posterior spiracle with 1 trilocular or 

 quinquelocular pore ; leg setae, coxa 3, femur 1 on inner margin near base, tarsus 

 1 each on inner and outer margins : tibia one-third as long as tarsus ; 9 pairs of 

 submarginal 8-shaped pores ; 7 pairs of submarginal minute setae on abdomen, 

 1 pair of submarginal larger setae at anterior end; 2 pairs of setae between 

 antennae and mouth parts. 



Apex of abdomen : Setae, apical 66 n long, interapical 7-10 n long, outer ventral 

 4-7 jx long; anal opening apical; anal tube very short, slightly sclerotized; anal 

 ring circular, sclerotized, with 2 setae, each about 7.2-9 /x long. 





