HABITS OF THE AMERICAN SAW-FLY, CIMBEI AMER¬ 
ICANA LEACH, WITH OBSERVATIONS ON ITS EGG- 
PARASITE, TRICHOGRAMMA PRETIOSA RILEY. 
HENRY H. P. .SEVEEIN AND HARRY C. M. SEVEEIN. 
(With Plate V) 
INTRODUCTION. 
While collecting the American saw-fly, Cirnbex americana, 
for anatomical and histological studies, our attention was 
drawn to the habits of this insect. The specimens were 
usually found on two species of willows, the peach-leaved wil¬ 
low, Salix amygdaloides, Anders., and the long-leaved willow, 
Salix longifolia Muhl. Our observation during the past sum¬ 
mer have been confined to Milwaukee County, Wisconsin, 
where we have had opportunities of watching the daily pro¬ 
gress of the insect. 
i 
DESCRIPTION OE MADE AND FEMALE SAW-FLY. 
As there is a considerable amount of individual variation in 
both male and female saw-flies, it has seemed advisable to de¬ 
scribe both sexes. The head and thorax of the female are 
shining black. Its abdomen is ovoid in shape and of a steel- 
blue color, with three, four or five whitish or yellowish mark¬ 
ings on each dorso-lateral side. The antennae are short and 
end in an egg-shaped knob; they are buff-colored, except to¬ 
wards the proximal end where they are somewhat darker. 
The wings are smoky brown and measure, when expanded, 
