76 Wisconsin Academy of Sciences, Arts and Letters. 
EXPLANATION OF PLATE V. 
All figures, except Figure 5, are drawn natural size. 
Fig. 1. Ventral surface of leaf of peach-leaved willow, showing an 
egg in each completed receptacle:— r, receptacle; 3r, three receptacles 
which communicate with one another; mr, mouth of receptacle; pr, par¬ 
tially completed receptacle; e, egg; p, egg parasitized by Trichogramma 
pretiosa; i, incision. 
Fig. 2. Ventral surface of leaf of long-leaved willow, showing the 
semi-circular lid which the larva pushes up in making its escape:— 
a, lid of receptacle; r, receptacle; mr, mouth of receptacle; pr, par¬ 
tially completed receptacle; i , incision. 
Fig. 3. Gashes or incisions which the saw-fly cuts in the twigs:— 
sc, spiral incision; tc, incision which extends completely around the 
branch; c, gash which extends only partly around twig. 
Fig. 4. A willow branch, a number of years after the injury, show¬ 
ing the incision healed over but with a splitting of the bark at ft. 
Fig. 5. Trichogramma pretiosa Riley, parasite of the eggs of Cimhex 
americana Leach. 
