8 BULLETIISr 438, U. S. DEPARTMENT OF AGRICULTURE. 



THE ADULT. 



Female. — Length 4.5 mm., very short and robust, shiny; head densely punctured, 

 rather opaque ; clypeus very slightly emarginate ; frontal wanting or very slightly indi- 

 cated; antennae very short, not as long as head and thorax, filiform, third joint longest; 

 intercostal nfearly at right angles with costa, interstitial with basal ; venation otherwise 

 normal; stigma short, broadly ovate at base; apex of costa strongly thickened; sheath 

 broad, slightly emarginate beneath and acuminate at tip; claws simple. Color black; 

 angles of pronotum, tegulse, trochanters, apices of femora (particularly anterior pair), 

 tibiae, and tarsi yellowish ferruginous; the posterior tibiae and tarsi particularly some- 

 what infuscated; veins, including stigma and costa, dark brown; wings hyaline. 



The females are more robust than the males. Upon issuing from the 

 cocoon the adult cuts a small circular hole almost all the way around 

 the end of the cocoon and issues by pushing up this "lid." Adults 

 (fig. 3) fly preferably in the fuU sunshine, but also in cloudy weather. 

 Their flight is jerky, and when captured they feign death. A great 

 amount of time is spent running about over the unfolding leaves and 

 buds, the antennae vibrating incessantly. They take food from the 



Fig. 3.— Pear sawfly, the adult of the pear leaf-worm. Much enlarged. 

 (Original.) 



nectaries of the leaves, and from observations it appears probable 

 that they also make shght incisions with the ovipositor and suck up 

 the moisture which collects at these wounds. (PI. I, fig. 1.) 



When ovipositing they run about in the same way, and at intervals 

 the abdomen is bent down and the tip of the ovipositor inserted in the 

 leaf, always on the under side, the leaves being mostly as yet unrolled. 

 Sometimes the place selected appears to be unsuitable, for the ovi- 

 positor is withdrawn after several seconds and inserted in another 

 place (PI. I, figs. 1,2). The whole process of oviposition occupies a 

 little less than two minutes. The ovipositor (fig. 4) normally lies in 

 its sheath, point up, and the abdomen must be curved under, so that 

 the point, which is extruded a httle way, may be inserted into the 

 leaf. The saws immediately begin to work back and forth, and after 

 about 30 seconds the ovipositor has been driven far enough into the 

 leaf epidermis so that it no longer needs the support of the sheath. 

 At this juncture the abdomen is straightened out, leaving the ovi- 



