THE GRAIN BUG. 



Fig. 5. — The grain bug : Nymph, second 

 instar (in early stages of the instar). 

 Much enlarged. 



Ventrally: Color uniform black, divisions of " shelf " white, rostrum light 

 brown, extending three-fourths length of venter; legs black. The legs are 

 sparsely pubescent in all stages of the insect. 



Described from 15 specimens. 



SECOND INSTAB. 



Length 2.2 to 2.53 mm. ; width of thorax 1.21 to 1.275 mm. ; width of abdo- 

 men 1.54 to 2.117 mm. 



During the development of the nymphs in the second instar a 

 change occurs in the color, 

 markings, and pubescence which 

 is not accompanied by any 

 visible molt. The description 

 of the nymphs in the early 

 stages of this instar (fig. 5) 

 follows: 



Dor sally: Head black, finely punc- 

 tate, sparsely pubescent throughout ; 

 eyes dark brown, prominent ; anten- 

 nae 1.375 to 1.485 mm. in length, light 

 salmon or brown, three terminal seg- 

 ments sparsely pubescent. Thorax 

 black, coarsely punctate, sparsely 

 pubescent on dorsum and at edge of 

 " shelf " ; four irregular yellow-white areas on anterior borders of prothorax 

 and mesothorax, with two small dots of same color on posterior border of meso- 

 thorax ; " shelf " white; Abdomen black, with a pale yellow double band ex- 

 tending transversely across the anterior border and 

 becoming enlarged near the margin ; posterior to 

 this band the mid-dorsal section is occupied by five 

 irregular bands of the same color and two brown, 

 slightly raised, elongated, elliptical areas bearing 

 the scent glands ; posterior margin sparsely pube- 

 scent ; " shelf " white. 



Ventrally: Uniform black except the white 

 " shelf " ; rostrum light brown, extending three- 

 fourths length of venter ; legs black. 



Fig. 6.— The grain bug : "^^^ following changes are observed in late 



Nymph, second instar stages of this instar (fig. 6) : 



(in later stages of the 



instar). Much enlarged. Borsally: Head pubescent only on anterior border, 

 anterior half impressed with two parallel sutures 

 on each side of median line. These parallel sutures persist in all the re- 

 maining stages of the insect. Antennae black. Thorax with a faint tinge of 

 green, no pubescence, finely punctate, no yellow-white areas. Abdomen with 

 decided tinge of green ; a narrow transverse yellow-white band occupying two- 

 thirds of the anterior border, and posterior to this band the mid-dorsal sec- 

 tion occupied by a small circular yellow-white area, two curved bands of the 

 same color, and two wider black irregularly ovoid areas, bearing the scent 

 glands ; " shelf " red-orange. 



Ventrally: " Shelf " red-orange on the abdomen. 



Described from 15 specimens. 



