678 



STATE BOARD OF AGRICULTURE. 



\h 



V 



Figure 13. 



Lecanium oleae. — Antenna ; spiracular setae ; and ventral 

 view of anal-plates ; sa, sub-apical setae ; a, apical setae ; 

 d, discal seta, the apical and discal setae being on the 

 dorsal surface. 



LECANIUM (Sassetia) HEMisrHAERicuM Targ. 



Female about 1/8 inch long, oval and strongly elevated in old ex- 

 amples. Smooth with the edge flaring slightly so as to rest flat on the 

 plant. Color brown with darker mottlings. Younger specimens yel- 

 lowish or dirty-white with a suggestion of a median ridge and two trans- 

 verse ridges. 



Derm in cleared mounts marked all over with rounded, more or less 

 oval, clear spots. There are also many tubular glandular openings scat- 

 tered over the derm. There is also a group of round gland-pores in 

 vicinity of the spiracular setae and often a row of them extending to 

 the spiracles themselves. Antennae slender, usually of eight articles. 



Anal-plates with fairly abrupt angle at cephalic point and at lateral 

 angles; caudal angles more rounded. Caudo-lateral margin longer than 

 cephalo-lateral. There are three or four fringe setae, often i)art of 

 them are very difficult to see. Two or three sub-apical setae, and three 

 aj)ical setae. There is always on each plate a prominent discal seta. 



Anal-ring with eight spines. Spiracular setae in groups of three of 

 which the middle one is long and slender, curved and either tinger- 

 sliaped or sword-shaped and sharj)ly ]x)inted. The two outer si)iracular 

 setae pointed like daggers. Marginal setae slender, some needle-shaped 

 but many with fringed tips and all with Imlbous bases. 



A common scale of green-house plants. Not found on native plants 

 which pass the winter out of doors. 



