Feb. 12,1917 
Tetrastichus bruchophagi 
281 
ment indistinct molting is apparent, and fragments of the cast-off larval 
skin may be noticed peeling off of the developing larva. The fully 
developed larva has frequently been found to be almost inclosed within 
the old larval skin. In other cases this cast-off skin has been observed to 
be worked back over the body of the larva. 
Dormant period. —After the larva has become full grown, further 
development toward the pupal stage depends largely upon external cli¬ 
matic conditions to which the seed is subjected. Complete drying of the 
seed containing this parasite delays pupation, and, in fact, may produce 
a dormant period to the larval stage of indefinite duration, or until both 
humidity and temperature are favorable for further development. This 
dormant period frequently begins in early summer and carries the species 
to the following year before further development takes place. Material 
kept in the laboratory showed adults of this species emerging almost two 
years after the seeds containing the parasite larvae had been collected in 
the field. 
Description. —The larva (PI. 78, A) varies in color from clear white to 
smoky white, and some of them have been found to be almost cream 
colored. They average 1.3 mm. in length and 0.66 mm. in diameter. 
The general shape is elliptical when at rest. At times the larva takes on a 
pear-shaped form. It has a small head and 13 body segments. The 
first three body segments back of-the head are slightly wider than the 
others. The body is free from pubescence and smooth, very lightly seg¬ 
mented. The mandibles are very small and almost invisible. 
Length of earvae stage. —The length of the larval stage depends 
greatly upon the duration of. the dormant period into which it enters, 
but under the most favorable conditions this period does not require more 
than about 10 days and pupation follows soon after the larva is fully 
developed. 
Prepupae stage. —Before entering the pupal stage, a prepupal period 
of about 48 hours' duration occurs. During this time the formation of the 
pupa within the larval skin takes place' and the larva loses its normal 
shape. 
PUPA 
PuPATiON.^-After the pupa (PI. 78, B) has formed within the larval 
skin, the latter breaks open along the dorso-anterior margin and is worked 
back until it is free from the body of the pupa. 
Description. —The pupae measured averaged 1.2 mm. in length and 
0.7 mm. in width. At first the pupa is white, but later the eyes take on a 
brown color and the body becomes black. The body of the pupa is 
rather straight, with head bent slightly forward. The appendages are 
folded close to the body and the pupa is covered by a thin pupal skin. 
Before changing to the adult stage the pupa becomes almost black, with a 
blue-green metallic luster. 
