10 THE BEAN THEIPS. 
THE ADULT MALE. 
The male resembles to a great extent the female, as the color 
and the - markings are the same, but it is noticeably smaller in size 
and apparently more active. When viewed under the microscope 
the sexual organs are seen to be distinctly different, and in light- 
colored or cleared specimens the testes may be seen as two orange-red 
bodies in the abdomen, and on the middle of each of segments 2 to 6 
on the ventral side are yellowish oval spots. The total length of 
the male is 0.T097 mm. to 0.8002 mm. ; the average, 0.7474 mm. The 
greatest width across the mesothorax is 0.1963 mm. to 0.2114 mm.; 
the average, 0.1978 mm. 
RECENTLY EMERGED ADULTS. 
Both sexes, when just emerged, have the head and thorax a light 
yellowish orange, with the eyes and ocelli bright red. The antenna? 
are white and ringed with brown, while the wings are dusky, crossed 
by bands of a darker color. The legs are 
white, with ends of each segment more or less 
black. Gradually the color darkens, and in 
a day they all have the fully matured colors, 
as described above. 
THE EGG. 
fig. 3. —The bean thrips : The egg (fig. 3) is bean shaped, 0.21 to 
?o?lin*n eatly enlarged ' 0.255 mm. in length and 0.105 to 0.12 mm. in 
width, and is very delicate and thin shelled. 
It is translucent white, with a smooth shining surface. The eggs are 
laid in the tissue of the leaf or in the veins, or even in the stems, and 
in case of beans may be laid in the pods themselves. As the embryo 
within develops, the egg becomes swollen, and the little pocket in 
which it is inserted becomes raised above the leaf surface. The eggs 
may be seen in the leaf tissue if examined with a hand lens before 
the light. Each little egg pocket stands out, because of its lighter 
color, and within the crude outline of the egg may be seen. 
The younger stages of this insect differ distinctly from those of 
Heliothrips 7uemorrhoidalis 1 in the dashes of crimson so generally 
present on the sides. 
THE FIRST- STAGE LARVA. 2 
(Fig. 4.) 
Length, 0.42 mm. ; width of mesothorax, 0.135 mm. General shape fusiform, 
similar to Heliothrips liwmorrlioidalis ; head, antennae, and legs large in propor- 
1 For description of HcliotJirips licemorrlwidalis, see " The Greenhouse Thrips," Bui. 64, 
Part VI, Bur. Ent., U. S. Dept. Agi\, pp. 46-48, 1909. 
2 Description made while larva was very young and before feeding commenced. 
