14 
BULLETIN 964, U. S. DEPARTMENT OF AGRICULTURE. 
EGG. 
Fig. 10. 
Egg cylindrical, roundly pointed at caudal end, broadly truncate at cephalic 
end. One side decidedly convex, opposite side slightly concave. Chorion smooth, 
lustrous, pearly white, semitransparent, free from sculpture, except surface of trun- 
cate end, which is roughly shagreened. Truncate end apparently with a collar, 
below which the egg is slightly constricted, end ellipsoidal in outline. Dimensions, 
long diameter, 0.21 mm., short diameter, 0.10 mm. Length of egg, outer angle 0.71 
mm., length of inner angle, 0.56 mm. Diameter at widest point, 0.20 mm. 
NYMPH. 
Figs. 11-15. 
The nymph resembles the adult in general outline and structure 
but differs in color, and has, in the place of wings such as the adults 
Fig. 10.— Halticus citri: a, Eggs in alfalfa leaf: b; egg greatly 
enlarged. 
Fig. 11.— Halticus citri: First 
nymphal instar. Greatly 
enlarged. 
have, dark-colored wing pads, these being most pronounced in the 
fifth stage. In the first nymphal instar the body is less robust and 
of a pale clay-yellow color at hatching which turns to pale green 
after feeding. During the period from the second to the fifth 
instars, inclusive, the thorax and abdomen increase in size laterally. 
The body gradually becomes more robust, and at the fifth instar it 
has assumed almost the shape and form of the adult. The color of 
the body varies from a light to a dark green. 
The period of time consumed in the development of the nymph 
ranges from 10 to 18 days, or an average of 14 days, as shown in 
Table V. 
FIRST INSTAR. 
Fig. 11 
Length 0.70 mm., width 0.19 mm. (average of 6 specimens). Number of body joints 
13. Segments of abdomen 10. Head, thorax, abdomen, and all appendages pale clay 
color. Head as wide as body, as long as wide. Eyes lateral and prominent, oval 
shaped, with hexagonal facet structure, carmine in color. Beak 0.21 mm. long; three 
joints, dark at apex. Antennae tubular; composed of four joints, first slightly swollen, 
length 0.08 mm., second 0.15 mm., third 0.20 mm., fourth 0.25 mm. ; total length 0.68 
mm. . 
