DEPARTMENT BULLETIN 119. 



THIBD INSTAE. 



Fig. 7.- 



-The grain bug : Nymph, third instar. 

 Much enlarged. 



Length 3.08 to 3.19 mm. ; width of thorax 1.925 to 2.035 mm. ; width of abdo- 

 men 2.365 to 2.805 mm. 

 Dorsally: Head black, finely punctate, slightly pubescent ; eyes black, promi- 

 nent; antennse 1.925 to 1.98 

 mm. in length, black, two termi- 

 nal segments very finely pubes- 

 cent. Thorax black with dis- 

 tinct tinge of green, coarsely 

 punctate ; " shelf " white dur- 

 ing early stage of instar, later 

 becoming orange in color. Abdo- 

 men dark green and bearing 

 approximately the same mark- 

 ings as later stages of preced- 

 ing instar, and black coarse 

 punctations ; segmentation em- 

 phasized by black lines in this 

 and in the remaining nymphal 

 instars ; " shelf " orange color. 

 Tentrally: Head and thorax 

 green. Abdomen pale green, a' 

 black circular area on each of 

 the four terminal segments; 

 anal opening black. These 

 black areas persist on the venter 

 of the remaining nymphal instars. " Shelf " orange on both thorax and abdo- 

 men. Rostrum green, extending slightly more than one-half length of venter. 

 Legs: Coxas, trochanters, and femora green; tibiis and tarsi bro^^^l. 



Described from 7 specimens. 



FOTJRTH INSTAB. 



Length 5.2 to 6.6 mm. ; width of 

 thorax 8.1 to 8.75 mm. ; width of 

 abdomen 3.8 to 4.9 mm. 



Dorsally: Head pale green, finely 

 punctate ; eyes reddish black, not so 

 prominent as in preceding instars; 

 antennte 3.4 to 3.7 mm. in length, 

 dark brown or black. Thorax pale 

 green with darker coarse puncta- 

 tions ; wing pads visible as slightly 

 raised areas on both sides of thorax ; 

 " shelf " white with a red-orange 

 edge. Abdomen pale green ; puncta- 

 tions numerous, coarse and darker 

 green in color ; a narrow yellow 

 transverse band occupying one-half 

 median portion of abdomen on an- 

 terior border, and posterior to this 



band the mid-dorsal section occupied by a short narrow yellow band, four 

 circular areas of the same color, and two brown erescentic projections bear- 

 ing the scent glands; black coarse punctations more numerous than in preced- 

 ing instar ; " shelf " white with red-orange edge. 



Fig. 8. — The grain bug : Nymph, fourth 

 instar. Much enlarged. 



